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	<title>IanVisits - The Blog &#187; subterranean stuff</title>
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		<title>The strange appeal of walking through tube tunnels</title>
		<link>http://www.ianvisits.co.uk/blog/2010/03/12/the-strange-appeal-of-walking-through-tube-tunnels/</link>
		<comments>http://www.ianvisits.co.uk/blog/2010/03/12/the-strange-appeal-of-walking-through-tube-tunnels/#comments</comments>
		<pubDate>Fri, 12 Mar 2010 10:40:42 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[dlr]]></category>
		<category><![CDATA[london underground]]></category>
		<category><![CDATA[rotherhithe]]></category>
		<category><![CDATA[thames tunnel]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=2251</guid>
		<description><![CDATA[It might sound like a rather obscure sort of event that just a few people would be interested in &#8211; yet Londoners have leapt at the chance to walk through the Thames Tunnel at Rotherhithe this weekend.
Tickets for the evening and Saturday visits were sold out almost as soon as they were announced &#8211; with [...]]]></description>
			<content:encoded><![CDATA[<p>It might sound like a rather obscure sort of event that just a few people would be interested in &#8211; yet Londoners have leapt at the chance to <a href="http://www.ianvisits.co.uk/blog/2010/03/04/brunels-thames-tunnel-open-to-the-public/">walk through the Thames Tunnel</a> at Rotherhithe this weekend.</p>
<p>Tickets for the evening and Saturday visits were sold out almost as soon as they were announced &#8211; with the phone line and (decrepit) website suffering under the load of requests. People are now begging for tickets almost as if they are trying to attend a pop-concert.</p>
<p>Thames Tunnel Ticket Touts could make a fortune tonight!</p>
<p>This level of interest in our deep subterranean world shouldn&#8217;t really surprise people though &#8211; as most of us have a weird fascination with the hidden and mysterious. Even the most disinterested person is going to be mildly curious in seeing what lies beyond the dark voids they occasionally see in the tunnels on their daily commute.</p>
<p>I have a long habit of trying to get into subterranean locations &#8211; sometimes with success &#8211; and also do a little lobbying on trying to get places opened up where I genuinely think it is possible.</p>
<p>That latter part has been singularly the most disappointing though &#8211; as people cry that health and safety is a worry (rarely is) or that no one would be interested (oh, boy are they interested!).</p>
<p>It&#8217;s even worse when I don&#8217;t even get a reply though &#8211; as then I can&#8217;t be sure if an idea was evaluated and rejected &#8211; or simply thrown in the bin without consideration.</p>
<p>An example of the later would be an email I sent to the DLR last year when the Xmas closure of Bank station was announced. The proposal was simple. It is just about possible to walk onto the Bank line from a side road just before it dips into the tunnel, so why not open the tunnel up to the general public to walk down over the Xmas weekend before the engineering works started?</p>
<p>I just knew that hundreds, if not thousands of people would have leapt at such an opportunity. Not because the tunnel is historic, but because the opportunity is rare, and the walk would be a singularly unusual event to take part in.</p>
<p>No reply &#8211; not even a &#8220;<em>don&#8217;t be stupid, don&#8217;t you realise there are a hundred and one reasons why that can&#8217;t be done!</em>&#8221;</p>
<p>The Thames Tunnel tour will also include a recreation of the Funfair element, but that is a mere sideshow for most people who seem to be going down under the river. It is the tunnel that is the main event here, so other opportunities to open tunnels shouldn&#8217;t be reliant on being able to put on a big show. The tunnel <strong>is</strong> the show!</p>
<p>Maybe the huge demand for tickets to the Thames Tunnel will encourage more openings like this where possible?</p>
<p>I do appreciate the problems in opening subterranean venues though &#8211; the organisation, the volunteers needed, the inevitable worries about insurance and crowd control &#8211; not to mention ensuring there are no trains using the tunnel at the time!</p>
<p>For that reason, despite people expressing hopes that the Thames Tunnel tour will happen again, I suspect that repeats will be unlikely, simply because you are asking train passengers to lose a fairly important cross-river link. We shouldn&#8217;t forget in our desire to visit these places that they have a primary function, and being a tourist attraction isn&#8217;t it.</p>
<p>I wont mention details in case plans are being plotted, but I did get a &#8220;hmm, interesting&#8221; from a suitably connected person at London Underground a year ago for a proposal to open up a bit of abandoned station and a tunnel for a weekend in a way that got around most of the health and safety worries that come from having loads of people in sometimes constrained areas.</p>
<p>Fingers crossed that it happens, and even if it doesn&#8217;t, at least I know someone read the email and considered the proposal. That simple act is often worth the effort, even if nothing comes of it in the end.</p>
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		<title>Brunel&#8217;s Thames Tunnel Open to the Public</title>
		<link>http://www.ianvisits.co.uk/blog/2010/03/04/brunels-thames-tunnel-open-to-the-public/</link>
		<comments>http://www.ianvisits.co.uk/blog/2010/03/04/brunels-thames-tunnel-open-to-the-public/#comments</comments>
		<pubDate>Thu, 04 Mar 2010 10:45:14 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[Events and Tours]]></category>
		<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[brunel]]></category>
		<category><![CDATA[east london line]]></category>
		<category><![CDATA[london underground]]></category>
		<category><![CDATA[rotherhithe]]></category>
		<category><![CDATA[thames tunnel]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=2208</guid>
		<description><![CDATA[Warning &#8211; tickets are SOLD OUT. You can try turning up in the hope that people have spares, but that is about it. The Brunel Museum will however resume their floodlit tunnel train trips in a few months time.
In the meantime, here is my report of my visit to the tunnels.

On the weekend of the [...]]]></description>
			<content:encoded><![CDATA[<blockquote><p>Warning &#8211; tickets are SOLD OUT. You can try turning up in the hope that people have spares, but that is about it. The Brunel Museum will however resume their floodlit tunnel train trips in a few months time.</p>
<p>In the meantime, here is <a href="http://www.ianvisits.co.uk/blog/2010/03/13/walking-though-brunels-tunnel-under-the-thames/">my report of my visit</a> to the tunnels.</p></blockquote>
<hr />
<p>On the weekend of the 12th-13th March, the <a href="http://en.wikipedia.org/wiki/Thames_Tunnel">world&#8217;s first underwater tunnel</a> &#8211; at Rotherhithe &#8211; will be open to the general public.</p>
<p><a href="http://www.ianvisits.co.uk/blog/wp-content/uploads/2010/03/300px-Thamestunnel.jpg"><img class="alignright size-full wp-image-2209" title="300px-Thamestunnel" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2010/03/300px-Thamestunnel-e1267699351462.jpg" alt="" width="200" height="144" /></a>Neither the <a href="http://www.brunel-museum.org.uk/">Brunel Museum</a> nor the <a href="http://www.ltmuseum.co.uk/">LT Museum</a> websites have any details &#8211; but phone the LT Museum on 020 7565 7298 and grab some tickets.</p>
<p>As it happens, I knew there were plans to do something prior to the line being reopened for trains, but I thought they had been cancelled.</p>
<p>The Brunel Museum used to take a slow tube train through the tunnels with the tunnel lights switched on to show off the structure, but this is presumed to be a walking tour through the tunnels before it is handed over to live trains again.</p>
<p>Woo!</p>
<p><strong>Update:</strong> The<a href="https://ticket.ltmuseum.co.uk/peo/default.asp"> LT Museum website now has details</a> &#8211; and it is indeed a guided walking tour from one end to the other, and back again. Self-evidently, the start/stop point will be the Rotherhithe side as that is where the museum is sited &#8211; along with the soon to be refurbished shaft area.</p>
<p>Note &#8211; Like turning up to a nightclub wearing trainers, there is a dress code and trainers are not permitted. You need to have <em>sturdy shoes</em> for the tour.</p>
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		<title>Riding the last ever fully circular circle line train</title>
		<link>http://www.ianvisits.co.uk/blog/2009/12/16/ridin-the-last-ever-fully-circular-circle-line-train/</link>
		<comments>http://www.ianvisits.co.uk/blog/2009/12/16/ridin-the-last-ever-fully-circular-circle-line-train/#comments</comments>
		<pubDate>Wed, 16 Dec 2009 15:33:29 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[circle line]]></category>
		<category><![CDATA[london underground]]></category>
		<category><![CDATA[twitter]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=1853</guid>
		<description><![CDATA[On Sunday morning, the Circle Line uncurled slightly into a spiral, and to commemorate the death of the circle, a small group decided to take the very last ever train to run right round the whole circle line on the prior Saturday night.
Starting at Tower Hill and looping round the network back to Tower Hill [...]]]></description>
			<content:encoded><![CDATA[<p>On Sunday morning, the Circle Line uncurled slightly into a spiral, and to commemorate the death of the circle, a small group decided to take the very last ever train to run right round the whole circle line on the prior Saturday night.</p>
<p>Starting at Tower Hill and looping round the network back to Tower Hill about an hour later.</p>
<p>Although I had consulted widely to confirm that the timetable was correct, I popped into Tower Hill earlier that evening to double-check with the staff. I needn&#8217;t have bothered as the woman behind the counter seemed completely incapable of understanding the simple question I was asking and kept replying with the same incorrect information about the very last train to leave the station.</p>
<p>Fortunately, the barrier staff understood instantly what I wanted and although not sure of the exact details, agreed that my presumption sounded about right.</p>
<p>A few beers later with friends and over to the station, where we met up with the small contingent of fellow tube geeks who had decided to honour the dying moments of the circle line.</p>
<p>Although the timetable suggested 23:37 was the train to catch, the train indicator was showing delays, so when a train at roughly the right time arrived, we weren&#8217;t actually sure if it was the Very Last Train. No announcements or indications that it was The Train.</p>
<p>Taking a risk, we took that train and as we arrived and waited at Aldgate, the station announcer confirmed that this was indeed the <a href="http://twitter.com/ianvisits/statuses/6613313851">Very Last Train</a>. Much excitement!</p>
<p>Slowly round the line we went until we arrived at Baker Street, and took the last circle line train that would ever travel round the track from the East towards Kensington High Street.</p>
<p>Apart from that it was really just a trip on the circle line round to Tower Hill, although I stuck my head out at almost each station to take a photo of the platforms.There was also some amused looks from some of the fellow passengers at our (gasp!) <a href="http://www.flickr.com/photos/helenduffett/4181499126/">photo snapping antics</a> on the train.</p>
<p>Sadly, considering that it was the last ever trip &#8211; apart from the station announcer at Aldgate &#8211; not a single mention was made on the train or at any other stations.</p>
<p>Eventually arriving at Tower Hill, as we departed for the last time, a crowd got on to catch the train on its partial loop round to Liverpool St Station &#8211; oblivious to the unmarked grave of the circle line they were embarking.</p>
<p>Those of us who turned up were largely there due to messages on Twitter &#8211; so a <a href="http://twitter.com/#search?q=circlelineparty">live commentary</a> was provided though the trip.</p>
<p>I managed to take a &#8220;souvenir&#8221; photo of most of the stations we pasted though &#8211; photos at <a href="http://www.flickr.com/photos/ianvisits/sets/72157623012514656/">Flickr</a> as usual.</p>
<p>Thanks to everyone who came along as well &#8211; it was fun. </p>
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		<title>More on the &#8220;secret&#8221; tunnel under Whitehall</title>
		<link>http://www.ianvisits.co.uk/blog/2009/11/20/more-on-the-secret-tunnel-under-whitehall/</link>
		<comments>http://www.ianvisits.co.uk/blog/2009/11/20/more-on-the-secret-tunnel-under-whitehall/#comments</comments>
		<pubDate>Fri, 20 Nov 2009 16:40:11 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[telecommunications tower]]></category>
		<category><![CDATA[tunnel]]></category>
		<category><![CDATA[whitehall]]></category>
		<category><![CDATA[ww2]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=1760</guid>
		<description><![CDATA[There are many rumours of secret tunnels and facilities under London operated  by the government, and while the vast majority of the rumours are just wishful  thinking, various stories of a secret tunnel network under Whitehall are based  on a very real and substantial tunnel.
During World War 2, the number of telecoms [...]]]></description>
			<content:encoded><![CDATA[<p>There are many rumours of secret tunnels and facilities under London operated  by the government, and while the vast majority of the rumours are just wishful  thinking, various stories of a secret tunnel network under Whitehall are based  on a very real and substantial tunnel.</p>
<p>During World War 2, the number of telecoms exchanges in London was quite  limited, and one of the main exchanges was based in the City of London &#8211; quite  some distance from Whitehall. As above ground phone lines was out of the  question, a hybrid network was created.</p>
<p>In essence, a tunnel under Whitehall was built using conventional tube tunnelling  techniques. Cables from here could be routed up to the then Trafalgar Square  Station (now Charing Cross), run round to the Bakerloo Line and then through  that tunnel down to Waterloo Station. Here, the cables routed round to the  Waterloo &amp; City line and not far from Blackfriars station, a narrow pipe was  sunk to run the cables up to the Faraday Building.</p>
<p>Other cables were routed from Whitehall to systems outside London also by  being laid through the tube tunnels and then to overground networks away from  the main bombing targets.</p>
<p>This secret government &#8220;escape tunnel&#8221; is actually just a service  tunnel &#8211; albeit rather a large one. Q-Whitehall is the (possibly unofficial)  name given to it. Although not really designed for regular human use, it could  be used as a route between Whitehall buildings in emergencies, such as during  gas attacks.</p>
<p>Back onto the rumours, it is widely known that quite substantial upgrade work was carried out  in the 1950s, and the file for that is locked away in the <a href="http://www.nationalarchives.gov.uk">National Archives</a> awaiting declassification. Put a note in your diaries for 2026, as that is when  they will be released. Another unfounded rumour is that a further upgrade was  carried out about only a few years ago &#8211; but that came from just a single, if  usually reliable, source a few years ago.</p>
<p>Also, the Whitehall tunnel is reported to be linked to the deep level  telecoms tunnels (allegedly) constructed by the Post Office during the cold war.  Although British Telecom wont talk about their network, enough reliable, if  anecdotal evidence exists to show that it was a very real project. Not to  mention, a <a href="http://web.archive.org/web/20050422114116/http://www.iptvreports.mcmail.com/Tunneltrip.htm">journalist  who broke one day</a> and took photos!</p>
<p><strong>Why am I writing about it today?</strong></p>
<p>Well, just after WW2 ended, there was a short lived period where the  government talked openly about what it had done during the war, before  everything clamped down again as the Cold War started. In January 1946, the  trade magazine of the post office engineers &#8211; The Post Office Electrical  Engineers Journal &#8211; published a review of some of its activities, and it is one  of the very few sources of reliable information about the Whitehall tunnel.</p>
<p>Earlier this week, I finally managed to find a copy for sale and quite naturally  brought it.</p>
<p>Below, I present an excerpt from an article about defence communications  which details the deep level tunnel under Whitehall and within the tube tunnels.</p>
<p>Enjoy!</p>
<hr /><strong>The Post Office Electrical  Engineers Journal &#8211; Jan 1946, Pages 129-131</strong></p>
<p><em>Line Plant.</em></p>
<p>Although some measure of security was achieved  by the provision of alternative routing, the risk of  extensive damage to the heavy concentration of  trunk and junction cables in the central area was so  serious as to make it imperative to adopt an exceptional  and notable safeguard by diverting a number  of the cables to the public and Post Office tube railways,  and a deep tunnel which was specially constructed  during the war to accommodate Post Office  plant.</p>
<p>The construction of this tunnel, which is 7 ft. in   diameter, and at a depth varying between 70 ft. and   100 ft. below the surface proceeded from three working   shafts, one of which was retained as the leading-in   point for the cables. A lift of sufficient capacity to   take full size cable drums was installed in this shaft.   Owing to the need for conserving iron during the   critical period of the war, the greater part of the    tunnel was lined with reinforced concrete segments   instead of the customary cast iron. Plant was   installed for the ventilating, draining and lighting of   the tunnel. At one point an enlarged offset was constructed   to accommodate loading pots. Among the   arrangements for cabling was the provision of specially   designed roller skates, which were attached to the   cables to facilitate their movement to the appropriate section of the tunnel. A total of 60 cables with an   aggregate mileage of 62 was installed in the tunnel,   in which about 150 cables can ultimately   be accommodated.   A typical view of the tunnel showing the   cables in position is given in Fig. 4.</p>
<p style="text-align: center;"><img class="aligncenter size-full wp-image-1761" title="Image1" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/11/Image1.jpg" alt="Image1" width="500" height="390" /></p>
<p>SAFEGUARDING DEFENCE COMMUNICATIONS</p>
<p>Protection for defence communications was in  general more elaborate and certain in its function  than that provided for public communications, owing  to the fundamental importance of maintaining the  continuity of their service. In London this objective  was finally achieved by putting the plant deep  underground, or in exceptionally strong reinforced  concrete structures having walls several feet in  thickness. The most notable and comprehensive  scheme of this character was the tunnel system  constructed for the Service Departments.</p>
<p><em>Deep-level Protection.</em></p>
<p>This tunnel system is a comprehensive scheme of  deep-level protection in the vulnerable central area  for equipment and cables, carrying vital defence  communications from the buildings of the Service Departments to other parts of the country. Associated with these specially constructed tunnels are the public and P.O. tube railways.</p>
<p>The ultimate scheme represents the accretion of five principal component schemes which were  proceeded with at various times during the war. The   initial scheme, commenced in December, was a   tunnel 12 ft. in diameter and at a depth of about   100 ft., which, intended at the time solely for cable   protection, is connected by short lateral tunnels of 5 ft. diameter to the Service   Departments and Federal exchange. The   latter is a protected exchange in sub-ground   accommodation and was provided   at the outbreak of the war to give an   uninterrupted service for the principal   officers in Government Departments.</p>
<p>Access to the main tunnel for Post Office   personnel is provided by an automatic lift   and emergency staircase in a shaft at an   exchange, which is connected to the main   tunnel by an 8 ft diameter lateral tunnel.   The cables from the buildings of the   Service Departments. after being taken   through 12-in steel bore tubes connected     to the smaller lateral tunnels, are terminated   on the M.D.F. in the main tunnel   A portion of this M.D.F. can be discerned   in Fig. 5.</p>
<p style="text-align: center;"><img class="aligncenter size-full wp-image-1762" title="Image2" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/11/Image2.jpg" alt="Image2" width="500" height="405" /></p>
<p>It was obvious that the main tunnel   would afford absolute security for telephone   and telegraph equipment, the first   installation of which was accordingly proceeded   with and completed in the summer   of 1941 to meet the increasing requirements for defence   communications. This equipment, which has been   added to from time to time, and now provides for   about 4,000 working circuits, includes among the   many constituent items, 71 18-channel V.F. systems,   26 canner systems, 13 coaxial cable terminals and 864 audio amplifiers A small portion of this equipment may be seen in Fig 6.</p>
<p style="text-align: center;"><img class="aligncenter size-full wp-image-1763" title="Image3" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/11/Image3.jpg" alt="Image3" width="500" height="408" /></p>
<p>During 1941-42 major extensions of the tunnel, which more than doubled its length, were carried out,  affording underground access between various Service Departments and accommodating a  teleprinter switched centre.       In all, a, total of 1 mile 740 yards of tunnel has been constructed under the various schemes associated with the  tunnel system and six shafts with passenger lifts provided The tunnel system is  connected via the tube railways to the Citadel building.</p>
<p>These specially constructed tunnels and the public and P.O tube railways have  been extensively used to   give deep-level protection to cables carrying vital  communications. A total of 72 miles of cable has been laid in P.O. tunnels, 116 miles  in public tube railways and 20 miles in the P.O. railway</p>
<p><em>&#8220;Citadel&#8221; Protection.</em></p>
<p>The tunnel system and its connection with the tube railways is an outstanding  example of absolute protection for both telecommunication equipment and cables, but there were many   other schemes  during the war where circumstances only warranted, or made practicable, a lesser degree of  physical protection. The Service Departments had many subsidiary installations for operational control,  which, situated in areas subject to desultory bombing, accommodated very important equipment As this   equipment could not be replaced with sufficient speed   without serous interruption to the operational   control, it was essential to provide very substantial   protection for the installations. The associated line   plant, although equally important could be more   readily restored in the event of damage, and, moreover,   the resulting interruption could be minimized   by the provision of alternative routing. The physical   protection for such installations usually took the   form of a massive reinforced concrete structure,   either wholly or partly below ground, with wails and   roof several feet in thickness and the interior subdivided   to limit blast effects from direct hits which   might penetrate the structure.</p>
<p>In the London Telecommunications Region there   were nearly a dozen such structures, many accommodating   a considerable amount of telephone and   telegraph equipment. Fig. 7 shows a view of the     switchboard installed in one of these     Citadels. In addition, the installation   included telegraph equipment for   123 teleprinters and other equipment for   the remote control of radio transmitters.   Steel pipes for leading in the cables   at alternative points were laid during   the construction of the Citadels.</p>
<p style="text-align: center;"><img class="aligncenter size-full wp-image-1764" title="Image4" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/11/Image4.jpg" alt="Image4" width="500" height="404" /></p>
<p><em>Supplementary Security for Line Plant</em></p>
<p>In London the tube railways were used  extensively to give deep-level protection  for a few miles for the cables radiating  from the central equipment. Beyond the  emergent points from the tube railways,  however, the cable routes were as  vulnerable as any other underground  plant at shallow depth, and with the  persistent and widely dispersed bombing  in 1940-41, the incidence of damage to  these routes was sufficiently serious to  require special measures to mitigate the  effects of the interruptions.</p>
<p>The scheme adopted entailed the linking up, by circumferential cables, of the radial cable routes in   the tube railways at a number of selected interception   centres located not far from the emergent points.   Included in the scheme were many of the surface   trunk cables, which were intercepted at exchanges   adjoining the main routes. At several places where   the circumferential and radial routes intersected, and exchanges were not conveniently situated to intercept  them, substantial pill-box structures, in which an   interception frame was installed, were constructed.   Interruption by bomb damage to any of the radial   cable routes could thus be readily restored by suitable   re-routing of the circuits over the circumferential   cables at the interception centres.</p>
<p>The London scheme, started in the late autumn of   1940 and completed during the following year,   involved the laying of 250 miles of loaded cable of   various sizes An interesting feature in the cabling   work was the completion of the circumferential cable   system across the Thames by using the 12 ft. diameter   pilot tunnel at Dartford, which had been constructed   before the war in preparation for building the main   vehicular tunnel.</p>
<p>The inclusion of the surface trunk cables in the  scheme enabled not only defence circuits to be rerouted,  but also important trunk circuits which had  been interrupted by bomb damage to the radial  routes, a facility which exemplified the duality of  purpose of the Post Office telecommunication   network  in the national prosecution of the war.</p>
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		<title>Ghosts on the London Underground</title>
		<link>http://www.ianvisits.co.uk/blog/2009/10/30/ghosts-on-the-london-underground/</link>
		<comments>http://www.ianvisits.co.uk/blog/2009/10/30/ghosts-on-the-london-underground/#comments</comments>
		<pubDate>Fri, 30 Oct 2009 18:30:19 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[History]]></category>
		<category><![CDATA[Random]]></category>
		<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[aldwych]]></category>
		<category><![CDATA[ghosts]]></category>
		<category><![CDATA[kennington loop]]></category>
		<category><![CDATA[london underground]]></category>
		<category><![CDATA[old bailey]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=1724</guid>
		<description><![CDATA[Considering the dark dark corners, strange noises and abandoned tunnels that litter the soil under London, it is possibly no surprise that stories of hauntings have emerged over the years.
On Wednesday, a couple of authors who have recently written a book on the subject gave a talk on the subject and I wandered along to [...]]]></description>
			<content:encoded><![CDATA[<p>Considering the dark dark corners, strange noises and abandoned tunnels that litter the soil under London, it is possibly no surprise that stories of hauntings have emerged over the years.</p>
<p>On Wednesday, a couple of authors who have recently written a book on the subject gave a talk on the subject and I wandered along to the <a href="http://www.ianvisits.co.uk/calendar/events/index.php?lID=111">Shoe Lane Library</a> to have a listen.</p>
<p>Ghosts are, despite their ethereal nature, quite a contentious topic and not unlike Marmite, they evoke very strong emotions in many people. Indeed, the authors had sometimes faced problems researching the book as people were worried about describing their experiences lest they be mocked in the staff-room.</p>
<p>My personal take on them is that unless you presume lots of people are lying, then something odd is going on &#8211; and I would love to understand the science behind the phenomena.</p>
<p>Interestingly, a survey from a couple of years ago by fairly well respected pollsters, Gallup found that belief in ghosts is higher now than at any time in the past 50 or so years.</p>
<p>Anyhow, the talk itself was a quick run though various hauntings and I&#8217;ll briefly summarise a few of them below:</p>
<p>They started off with a fairly notorious sermon by the Rev. John Cumming, who was not at all keen on the subterranean railways.</p>
<p>&#8220;<em>&#8230;the forthcoming end of the world will be hastened by the construction of underground railways burrowing into infernal regions and thereby disturbing the Devil.&#8217;</em>&#8221;</p>
<p>Certainly there were the odd complaints of this nature about the deep tunnels, but the Victorians were digging deeper coal mines at the time without bumping into Hades or its ilk, so their pronouncements of doom were generally ignored.</p>
<p>One more famous incidents occurs at Aldgate Station, where allegedly there is a log book for ghost sightings. Sadly, getting a glimpse of this log-book proves as elusive as the spectres they detail.</p>
<p>At the station, it was reported that a worker was knocked unconscious after accidentally touching a live power rail and as another worker went to assist him, the ghost of a lady was seen stroking the unconscious man&#8217;s hair. Some stories claim the lady saved the man&#8217;s life, but it seems more that she simply comforted him while help arrived.</p>
<p>Another station, with a similar name is the now disused <a href="http://www.ianvisits.co.uk/blog/2008/09/05/a-tour-of-aldwych-station-on-the-london-underground/">Aldwych Station</a>, which was built on the site of a theatre, and the ghost of an actress has occasionally been seen in the station.</p>
<p>Amusingly, a TV show did a series of investigations into hauntings, and the physic reported seeing in Aldwych the event that had (allegedly) occurred in Aldgate. I suspect someone was doing a bit of reading beforehand and mixed up their stations!</p>
<p>Bank Station is also noted as a site of hauntings, and as the ticket hall is actually the former burial grounds of St Mary Woolnoth Church, many researchers cite that as the possible cause.</p>
<p>The most noted of the Bank hauntings though is nothing to do with the old burial ground &#8211; being the ghost of Sarah Whitehead. Her brother, who worked at the nearby Bank of England was hung for fraud and she spent the next decade or so visiting the Bank each day to ask for her brother until she in turn eventually died.</p>
<p>Neither were buried in the former graveyard.</p>
<p>Over at Bethnal Green is one of the more sombre hauntings. The station entrance was the location for one of the most serious civilian losses of life during WW2 when a panicked crowd tried to seek shelter during an air raid, and 173 people died in a crush by the stairway entrance. What made it more tragic was that the air-raid sirens were a false alarm, and the panic caused by a loud booming sound, thought to be a bomb, was actually a new anti-aircraft gun that had just been set up in nearby Victoria Park.</p>
<p>Since then, there have been repeated reports of unsettling sounds and people feeling uncomfortable in the station.</p>
<p>For reasons that are not fully understood, there is a known tendency for low-frequency sounds to make people feel uncomfortable, and the tube tunnels are certainly replete with plenty of machines that cause similar effects.</p>
<p>However, when a worker reports the clear sounds of women and children screaming in the booking hall, and that it went on for a period of at least 10 minutes, you have to wonder what could possibly cause that effect.</p>
<p>To lighten the mood, back down the Central Line to the old British Museum station &#8211; which is a disused station between Holborn and TCR &#8211; where the ghost of a mummy was reported to have been seen. The reports of this haunting are, to put it mildly, dubious and can be discarded as urban myth.</p>
<p>Incidentally, you can still see what is left of the station as you pass though it on the Central Line. Regardless of which direction you approach it, peer out of the right-side windows and although the platforms have been removed, you can make out the empty remains of the station structure.</p>
<p>One of the more unsettling ghostly experiences is had by staff at Elephant &amp; Castle station where the Bakerloo Trains end their travels and prepare to return northbound. Late at night, a lady is sometimes seen getting onto an empty train which is to be returned to the depot, and when staff go to remove her, the carriage is empty again.</p>
<p>Incidentally, and a sign possibly of how our imaginations are important in ghost sightings &#8211; when it comes to ghostly trains, people rarely report the sound or sight of diesel engines. It&#8217;s always a steam train that is heard. You&#8217;d have thought some diesels would have got in on the act by now, but it seems not. Or maybe we humans cannot imagine a &#8220;modern ghost&#8221; and expect ghostly trains to be only from the steam era?</p>
<p>Back up to the Central Line &#8211; which seems to be overly generous with its hauntings &#8211; and we get to the up escalator at Marble Arch station. Here, several people have reported leaving a late train to ascend the escalator and feeling that someone is standing on the step right behind them, and leaning uncomfortably close towards them. Anyone turning around will find the escalator is empty. One lady reported that out of the corner of her eye she noticed him wearing a hat and smart black overcoat &#8211; and annoyed by his closeness when she also turned to confront him, the escalator was empty. She now wont use that station unless with friends.</p>
<p>The Screaming Spectre of Farringdon is quite famous and thought to be Anne Naylor, a girl adopted by hat maker, Sarah Metyard and cruelly treated until eventually she was murdered. Metyard&#8217;s attempted to disposed of the body into the sewer at Chick Lane, but parts of the body were discovered.</p>
<p>Eventually identified as the murderer, after her daughter turned her in, she was convicted at the Old Bailey in 1768 and sentenced to death. Her body, as was the norm at the time for murderers was handed to the Surgeons&#8217; Hall to be dissected for students to study then put on public display.</p>
<p>The ghost was thought to haunt the region of the sewer for some years, but is now heard quite distinctively at Farringdon Station. That she moved to the station is a bit odd, as the sewer in Chick Lane lead down to the River Fleet, and while the road no longer exists, it was on the site of the now derelict Smithfield meat market buildings &#8211; a good hundred yards away from the station.</p>
<p>Finally &#8211; one I was quite interested in.</p>
<p>The <a href="http://www.flickr.com/photos/ianvisits/3378517541/">Kennington Loop</a> is a bit of track that enables trains on the Northern Line to <a href="http://www.flickr.com/photos/17889585@N03/3612957779/">turn around</a> at Kennington. Passengers are never allowed on trains going round the loop, and drivers are said to quite dislike the tunnel.</p>
<p>Not only is it very noisy as the tight curve makes the wheels squeal on the tracks, but sometimes trains are held at the end of the loop waiting for space at the platform. Here, in the silence, drivers have reported hearing people talking in the carriage behind them and the sounds of doors slamming as if someone is walking through the train, even though they had checked to make sure it was empty before starting round the loop.</p>
<p>I&#8217;ve have the pleasure of taking the Kennington Loop, and in a <a href="http://www.ianvisits.co.uk/blog/2009/06/22/another-trip-on-a-1938-tube-train/">1938 tube train</a>, but sadly we didn&#8217;t stop at <em>the spot</em> to listen for the sounds of passengers long lost to history seeking to commune with us.</p>
<p>&#8211;</p>
<p>That&#8217;s a quick run though of some of the ghosts mentioned at the talk, and I have dug a bit deeper into the Farringdon Ghost story to find the <a href="http://archivemaps.com/mapco/bowles1775/bowles06_02.htm">location of the streets</a> involved. The book they have written is <a href="http://www.amazon.co.uk/Haunted-London-Underground-David-Brandon/dp/0752447467">Haunted London Underground</a>.</p>
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		<title>When the Central Line was used as a fighter plane factory</title>
		<link>http://www.ianvisits.co.uk/blog/2009/10/19/when-the-central-line-was-used-as-a-fighter-plan-factory/</link>
		<comments>http://www.ianvisits.co.uk/blog/2009/10/19/when-the-central-line-was-used-as-a-fighter-plan-factory/#comments</comments>
		<pubDate>Mon, 19 Oct 2009 12:16:47 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[london underground]]></category>
		<category><![CDATA[ww2]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=1684</guid>
		<description><![CDATA[Whilst looking for something totally different on the Discovery TV website, I came across an interesting short video clip about the time when Plessey occupied several miles of tunnel under London and set up a factory inside.
The Central Line extension from Liverpool St was built before the war, but not fitted out for trains until [...]]]></description>
			<content:encoded><![CDATA[<p>Whilst looking for something totally different on the Discovery TV website, I came across an interesting short video clip about the time when Plessey occupied several miles of tunnel under London and set up a factory inside.</p>
<p>The Central Line extension from Liverpool St was built before the war, but not fitted out for trains until the war finished &#8211; priorities being somewhat diverted. After the above ground Plessey factory was bombed by German planes, they decided to move nearly 2,000 people into the newly built tunnels.</p>
<p>The factory specialised in making components for fighter planes and bombers.</p>
<p>The     conversion of the Underground was completed in March 1942 at a cost of     £500,000 and gave Plessey 300,000 sq.ft. of factory floor.</p>
<p>The 4 and a half minute video clip is on the <a href="http://www.discoverychannel.co.uk/video/wartime-london-secret-weapons-factory/">Discovery Website</a>.</p>
<p style="text-align: center;"><a href="http://www.ltmcollection.org/photos/photo/photo.html?_IXMAXHITS_=1&amp;_IXSR_=01yB7NPSBZJ&amp;IXsummary=location/location&amp;IXlocation=Redbridge&amp;_IXFIRST_=19&amp;IXenlarge=i00007ix"><img class="aligncenter size-full wp-image-1685" style="border: 0pt none;" title="i00007ix" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/10/i00007ix.jpg" alt="i00007ix" width="450" height="350" /></a></p>
<p>Incidentally, I was looking to see if Discovery Science is going to repeat a program I saw last night about the Jubilee Line extension. While nearly a decade old, the documentary had loads of good footage of tunnels etc. Sadly, I can&#8217;t find a repeat date, but did notice that next <a href="http://www.discoverychannel.co.uk/tv-schedule/?type=series&amp;country_code=GB&amp;channel_code=SCUK-ENG&amp;series_id=122985">Sunday (25th Oct)</a>, there will be a programme about the building of the Singapore Underground.</p>
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		<title>Chord inside the Kingsway Subway Tunnel</title>
		<link>http://www.ianvisits.co.uk/blog/2009/10/10/chord-inside-the-kingsway-subway-tunnel/</link>
		<comments>http://www.ianvisits.co.uk/blog/2009/10/10/chord-inside-the-kingsway-subway-tunnel/#comments</comments>
		<pubDate>Sat, 10 Oct 2009 15:24:31 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[Events and Tours]]></category>
		<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[kingsway subway]]></category>
		<category><![CDATA[underground]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=1652</guid>
		<description><![CDATA[Today I finally achieved something I have wanted to do for years, and got to see a rather interesting bit of art into the bargain.
Underneath the Kingway road in Holborn lies the Kingsway Tramway that used to carry electric trams until it was closed down in the 1950s. Since then it has been basically a [...]]]></description>
			<content:encoded><![CDATA[<p>Today I finally achieved something I have wanted to do for years, and got to see a rather interesting bit of art into the bargain.</p>
<p><a title="Unlocking the gates at last by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3998222952/"><img class="alignright" src="http://farm4.static.flickr.com/3503/3998222952_0301a174f7_m.jpg" alt="Unlocking the gates at last" width="160" height="240" /></a>Underneath the Kingway road in Holborn lies the <a href="http://en.wikipedia.org/wiki/Kingsway_tramway_subway">Kingsway Tramway</a> that used to carry electric trams until it was closed down in the 1950s. Since then it has been basically a storage dump for the local council and only on very rare occasions opened to visitors.</p>
<p>Over the next few weeks though, a artist has managed to put a specially designed bit of industrial art inside this closed-off tunnel and is letting people in to have a look.</p>
<p>At the top of the ramp leading down to the subway is a set of locked gates that have stood guard over the entrance, mocking the passers-by who can often be seen peering through the railings and wishing they could stand on the other side.</p>
<p>Today, those gates were flung open and a group of us went down the slope to the dark cavern that hinted of wonders within.</p>
<p>After a brief warning that it would be a VERY bad idea to lean on anything as it is filthy down there, we were taken along the tunnel to the old Holborn Tram Station where we lingered for a short while posing for photos and looking around.</p>
<p style="text-align: center;"><a title="Holborn Tram Station by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3997478475/"><img class="aligncenter" src="http://farm3.static.flickr.com/2435/3997478475_fbf652ce16.jpg" alt="Holborn Tram Station" width="500" height="333" /></a></p>
<p>Then down to the art itself.</p>
<p>Basically, two large &#8220;knitting machines&#8221; that slowly rotate to uncoil ropes which twist to produce a single strand as the machines slowly pull apart along a wooden railway.</p>
<p style="text-align: center;"><a title="Chord by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3998231368/"><img class="aligncenter" src="http://farm3.static.flickr.com/2427/3998231368_0f577d6c76.jpg" alt="Chord" width="500" height="333" /></a></p>
<p>The blurb provided said:</p>
<p><em>Chord is concerned with the human perception of time, as both a linear and cyclical notion. The rope becomes a strong structural metaphor, a clear linear entity made up and formed by a cyclical process. Each point on the rope can be traced back to a certain moment during the cycle and duration becomes interchangeable with length, time with length, time with space, an hour becomes 20cm, a day five meters.</em></p>
<p>Which is yes, well, quite.</p>
<p>I sort of understand what he is trying to say, but frankly it is not really relevant for me. Either I will like it, or I wont &#8211; and explaining it may make me appreciate it more, but it won&#8217;t change whether I liked it.</p>
<p>Fortunately, this is something that I liked. Actually, I liked it a lot.</p>
<p style="text-align: center;"><a title="Chord by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3997469659/"><img class="aligncenter" src="http://farm3.static.flickr.com/2426/3997469659_cc00fb64ac.jpg" alt="Chord" width="500" height="333" /></a></p>
<p>There was something about the very crisp clean industrial machine slowly rotating its kitting yarns as it plied out the rope that really worked for me.</p>
<p>Setting it inside a semi-derelict site added to the experience.</p>
<p>One thing that doesn&#8217;t really come across from the photos, or the text I read about it is that the rotating structure moves quite quickly. Although the linear movement is imperceptible, the rotating is reasonably speedy. That seems to make it a much more interesting thing to look at.</p>
<p>Also, unlike some fussy art venues, here is one where people didn&#8217;t walk around in hushed awe, but darted around with cameras taking photos with gay abandon. This is art you don&#8217;t have to be reverential when granted permission to be within its presence.</p>
<p style="text-align: center;"><a title="Chord up close by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3997470499/"><img src="http://farm3.static.flickr.com/2560/3997470499_5b162bc896.jpg" alt="Chord up close" width="500" height="333" /></a></p>
<p>The guides who accompanied us down were happy to chat about the art, the tunnel or just gossip.</p>
<p>A hole in the roof was pointed out and they are going to have to work out how to cover it as the unfurling structure moves slowly down the tunnel. Otherwise you are going to get a wet chord.</p>
<p>That hole has allowed a lot of autumn leafs to fall down into the tunnel, and as a bit of art about time, I do like the idea that over this weekend, the spinning structure will &#8220;pass through&#8221; autumn.</p>
<p>No idea if it was designed that way, or if I am just pretending to be a &#8220;wanky art critic&#8221; when I noticed that.</p>
<p>Thirty minutes is what you get down in the tunnel and then you are eased back out into the sunlit lands.</p>
<p style="text-align: center;"><a title="Inside the Kingsway Subway by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3998235808/"><img class="aligncenter" src="http://farm4.static.flickr.com/3531/3998235808_e32bf04997.jpg" alt="Inside the Kingsway Subway" width="500" height="333" /></a></p>
<p>I went in unashamedly to see the tunnel. After years of anticipation, it was important for me that the art didn&#8217;t spoil the visit, and I am delighted that it added to the experience.</p>
<p>There are a <a href="http://measure.org.uk/show11/ex_11_education.html">range of events</a> around the installation, including a talk about the art and one about the tunnel.</p>
<p>Various other London bloggers I know have been down there already:</p>
<p><a href="http://diamondgeezer.blogspot.com/2009_10_01_archive.html#8683005360767497254">Diamond Geezer</a>, <a href="http://www.timeout.com/london/big-smoke/blog/8886/Tunnel_vision--Chord-in_Kingsway_Tram_Subway.html">Time Out</a>, <a href="http://carolineld.blogspot.com/2009/10/chord-at-kingsway-tram-tunnel-1-artwork.html">Caroline</a> and <a href="http://londonist.com/2009/10/in_pictures_chord_at_kingsway_tram.php">Londonist</a>.</p>
<p>You can book a free visit via the <a href="http://measure.org.uk/measurenews.html">Measure website</a>, but only have until the 8th November before those gates are once again firmly sealed shut in the face of curious visitors.</p>
<p>Some more photos on my usual <a href="http://www.flickr.com/photos/ianvisits/sets/72157622430443331/">Flickr account</a>.</p>
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		<title>London Open House Weekend &#8211; The Thames Tunnel</title>
		<link>http://www.ianvisits.co.uk/blog/2009/09/21/london-open-house-weekend-the-thames-tunnel/</link>
		<comments>http://www.ianvisits.co.uk/blog/2009/09/21/london-open-house-weekend-the-thames-tunnel/#comments</comments>
		<pubDate>Mon, 21 Sep 2009 17:35:00 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[Events and Tours]]></category>
		<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[brunel museum]]></category>
		<category><![CDATA[london open house weekend]]></category>
		<category><![CDATA[tunnels]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=1605</guid>
		<description><![CDATA[Lurking not too far from where I live is a subterranean marvel that is  considered to be one of the most important locations in engineering history. I  am referring to the currently closed off East London Line railway &#8211; for the tunnel  it runs through under the Thames is world&#8217;s first (successful) [...]]]></description>
			<content:encoded><![CDATA[<p>Lurking not too far from where I live is a subterranean marvel that is  considered to be one of the most important locations in engineering history. I  am referring to the currently closed off East London Line railway &#8211; for the tunnel  it runs through under the Thames is world&#8217;s first (successful) sub-aqueous  tunnel.</p>
<p>Not too far from the Rotherhithe tunnel is the <a href="http://www.brunel-museum.org.uk/">Brunel  Museum</a> situated within an old pumping station, but conveniently next to the  original deep shaft that Marc Brunel (father of more famous Isambard Kingdom  Brunel) sunk into the clay soil to get down to the depth where the tunnel would  stretch out under the river.</p>
<p>I won&#8217;t relate the torturous history of the tunnel itself &#8211; as that is amply <a href="http://en.wikipedia.org/wiki/Thames_Tunnel">told  elsewhere</a>, for my visit to was not to the tunnel but to the remains of that  original shaft.</p>
<p>I arrived at at the museum just as a lot of people were filing out to go to  the shaft, so I ahem, joined the crowd. I&#8217;ve been in the museum before as they  used to run tours of the two key stations, Rotherhithe and Wapping and take a  slow train between them.</p>
<p>As part of the refurbishment of the tunnels for the overland railway, the  shaft, which has always been empty from surface to deep underground has had a  slab of concrete installed and the upper space will be handed over to the museum  to clean up and turn into an extension. As the slab was finished off only a few  weeks ago &#8211; the opportunity here was to see the <a href="http://www.flickr.com/photos/ianvisits/3941102143/in/set-72157622425816478/">interior of the shaft</a> before it  is cleaned up again.</p>
<p>Getting in for visitors will be down a replica of the original stair case  that lined the tunnel when it was open to pedestrians &#8211; but our access was  through a <a href="http://www.flickr.com/photos/ianvisits/3941101167/in/set-72157622425816478/">tiny door</a> that you quite literally had to crawl through and then down  some scaffolding to the floor, which is about 3 stories below its roofline (and  about 2 stories below ground).</p>
<p style="text-align: center;"><a title="Inside the Brunel Shaft - 3 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3941884722/"><img class="aligncenter" src="http://farm3.static.flickr.com/2445/3941884722_164788d21e.jpg" alt="Inside the Brunel Shaft - 3" width="500" height="334" /></a></p>
<p>Here lots of photos were taken and a volunteer gave us a brief run through  why the shaft is so important in engineering history and some details of its  construction.</p>
<p>In essence, they had a huge metal ring, upon which they started building a  high wall. As the wall got heavier, it started sinking into the soft soil &#8211;  aided by workers inside digging out that soil. More bricks added, and the shaft  continues to sink into the ground. At one point it got stuck and even adding  50,000 bricks to the top of the shaft wouldn&#8217;t unstick the gigantic pipe.</p>
<p>Here there seems to be two variants of the solution &#8211; in essence, water  leaking into the shaft normally lubricated the sides and one weekend the whole  thing dropped down several metres. Whether this was an accidental switching off  of the water pumps over a weekend that had a fortuitous outcome, or a deliberate  decision seems to vary depending on who is telling the tale.</p>
<p>The shaft finally at its required depth, the tunnel under the river could be  cut out. A similar shaft on the north side was also built &#8211; although two more  shaft, four times wider to allow horses down to the tunnel never got built as  some idiot stuck a bridge at Tower Hill and ruined the finances of the tunnel.</p>
<p>Talk over and a climb back out through the tiny exit, and that was it. A short visit, but this subterranean geek was bouncing with delight to have been able to have a look around.</p>
<p style="text-align: center;"><a title="Leaving by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3941102815/"><img class="aligncenter" src="http://farm3.static.flickr.com/2435/3941102815_588055dec5.jpg" alt="Leaving" width="500" height="333" /></a></p>
<p>I took a quick look around the museum and picked up a guide book that I would  have brought last time I was there, only they couldn&#8217;t take cards and I was out  of cash on the day. I also had a long chat with one of the staff about the  pneumatic railway I am researching and he mentioned something about its  precursor at Crystal Palace I wasn&#8217;t aware of. More research needed. Yay!</p>
<p>It was a shame we couldn&#8217;t go down to the original tunnels &#8211; but I have done  a slow train tour through there before courtesy of the museum.</p>
<p>A slight rant &#8211; they let people into the shaft through a really tiny doorway &#8211; and yet  other underground structures with significantly easier access points refuse to open up for the  public visits due to &#8220;health &amp; safety&#8221; concerns. That really annoys me as it quite evidently isn&#8217;t a problem.</p>
<p>As usual &#8211; more photos over at <a href="http://www.flickr.com/photos/ianvisits/sets/72157622425816478/">Flickr</a>.</p>
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		<title>London&#8217;s Lost Tunnel</title>
		<link>http://www.ianvisits.co.uk/blog/2009/07/11/londons-lost-tunnel/</link>
		<comments>http://www.ianvisits.co.uk/blog/2009/07/11/londons-lost-tunnel/#comments</comments>
		<pubDate>Sat, 11 Jul 2009 18:10:39 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[History]]></category>
		<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[mail rail]]></category>
		<category><![CDATA[royal mail]]></category>
		<category><![CDATA[underground]]></category>
		<category><![CDATA[waterloo and whitehall pneumatic railway]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=1410</guid>
		<description><![CDATA[While tunnel affectionados will be familiar with the &#8220;Mail Rail&#8221; that runs under London, fewer know that it was in fact the second such system, and an earlier tunnel had been built to carry mail from the Post Office&#8217;s national sorting centre &#8211; by today&#8217;s St Pauls tube station &#8211; up to Euston Station.
Alas, a [...]]]></description>
			<content:encoded><![CDATA[<p>While tunnel affectionados will be familiar with the &#8220;<a href="http://www.ianvisits.co.uk/blog/2008/03/21/the-post-office-robot-railway/">Mail Rail</a>&#8221; that runs under London, fewer know that it was in fact the second such system, and an earlier tunnel had been built to carry mail from the Post Office&#8217;s national sorting centre &#8211; by today&#8217;s St Pauls tube station &#8211; up to Euston Station.</p>
<p>Alas, a financial failure, most of the tunnel still lies under London undisturbed save for the occasional intrusion by modern subteranean mechanical moles.</p>
<p>For me, learning about the tunnel was indirectly responsible for my ongoing, infrequent research of the <a href="http://www.ianvisits.co.uk/blog/2008/11/30/more-on-the-waterloo-whitehall-railway/">Waterloo and Whitehall Pneumatic Railway</a> &#8211; as part of that, I came across an article in <em>The Windsor Magazine</em> of April 1900. I managed to find a copy, only to find that the bit I wanted was just a single short paragraph &#8211; a problem that often aflicts my research, but in buying it I learnt of an attempt to resurect that older mail rail tunnel and return it back into use.</p>
<p>The attempt failed &#8211; but the story is facinating, and I transcribe it below for your enjoyment:</p>
<p>(all the images are linked to larger versions on Flickr)</p>
<p><strong>LONDON&#8217;S LOST TUNNEL</strong></p>
<p>£175,000 WORTH BURRIED FOR THIRTY YEARS</p>
<p>By Harry Thompson</p>
<p><a title="Image1 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3710527826/"><img class="alignright" src="http://farm4.static.flickr.com/3456/3710527826_111ac233bf_m.jpg" alt="Image1" width="201" height="240" /></a>Is  there any other city in the wide world where a cast-iron tunnel, 2¾ miles in  length, could lie disused, unknown, lost to the sensory of all but a few  scientists, for over thirty years, excepting London? I doubt it. For this  commercial hub of the universe spins onward at such a rapid rate, that the  doings of yesterday are already shrouded in mist, and those of a decade back  buried as deeply as if the dust of centuries, not years, lay upon them.</p>
<p>So  it is that, under the hurrying feet of millions, even echoing their tramp  through the heart of the great city, for long years has lain this almost  imperishable testimony to the enterprise, courage, and, alas ! mismanagement, of  certain of its citizens of the “Sixties.” Expert  engineers have examined the tunnel and proclaimed it to be composed of the very  best metal – “cast-iron such as is not turned out today,” to quote the  words of a prominent expert and but little affected by earth, moisture, or  disuse, for all its lengthy interment and neglect. Representing as it does the  burial of close on £200,000, is it not simply marvelous that no effort until  the present has been made to rescue this valuable property from the fungi and  huge, whiskered rats, and turn it to some profitable utility? The answer is that  the tunnel had been forgotten, simply lost, and the man who “found” it found  a gold-mine extending from the G.P.O. at St. Martin’s-le-Grand to Euston  Station. Should the sanguine hopes of the discoverer be realized and they are  based on the reports of the leading authorities he has “ struck” a payable  “lead” that is not likely to be “worked out” until flying machines are as  ubiquitous and numerous as hansoms in London streets.</p>
<p><a title="Image2 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3710528330/"><img class="alignright" src="http://farm3.static.flickr.com/2592/3710528330_e233343d23_m.jpg" alt="Image2" width="240" height="209" /></a>Mr.  George Threlfall, a consulting engineer, of 50 Fenchurch Street, “found” the  tunnel, and the story of his discovery is one of surmounting almost interminable  Alps-of-obstacles, and a period of five years occupied with continual struggle  before success crowned his efforts.</p>
<p>The  memorable year of 1863 welcomed the abolition of slavery in America,  shuddered at the fierce fighting of kin against kin in the Battle of  Gettysburg, grieved at the death-beds of three memorable men Thackeray, Stonewall Jackson, and General Sir James Outram-and showered sunshine and good  wishes on the marriage of H.R.H. the Prince of Wales.</p>
<p>It  saw also the opening of the Pneumatic Dispatch Company’s first section of the  tube that later, starting from Eversholt P.O., N.W., passed down Seymour Street  under the Euston Station, along Drummond Street, turning into Hampstead Road,  and continuing the length of Tottenham Court Road until New Oxford Street was  reached, under which it ran, and under Holborn plunging deeply down the Viaduct,  passing below Farringdon Street, shooting up into Newgate Street, and finally  reaching home in the old G.P.O. buildings on the corner nearer Cheapside. The  tube, which measures four feet in height by four and a half in width, was  erected to carry the mails and postal parcels between the two terminal points  and wayside offices by means of pneumatic pressure.</p>
<p><a title="Image3 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709717909/"><img class="alignright" src="http://farm3.static.flickr.com/2654/3709717909_9f2284c118_m.jpg" alt="Image3" width="159" height="240" /></a>A  lad with a pea-shooter utilizes pneumatic pressure in propelling his stinging  pellets by introducing a force of air behind them; in an inverse manner liquids  are imbibed thorough a straw by sucking the air out, when the interior liquid,  thas relieved from pressure, is forced by the weight of the atmosphere on the  outside liquid up through the straw. Both these forms of pneumatic pressure were  utilized to drive the loaded cars of the Dispatch Company thorough the tunnel.  The car ends fitted the tunnel to within an inch all round. The intervening space  was closed so as to be perfectly air-tight by a flange of stout indiarubber,  which clung tightly to tile tube&#8217;s interior.</p>
<p>The  air was sucked out from in front of a train of cars by an ingenious mechanical  arrangement. Two discs of wrought-iron, twenty-one feet in diameter, were  screwed on to the sides of an iron wheel having sixteen spokes. Between these  two discs, and separated from them, stood a third disc of a corresponding size.  Thus this cumbers some wheel, complete, contained thirty-two V-shaped cavities.  Briefly, it may be said that the revolution of these cavities at a great speed,  before huge bell-mouthed pipes, drew by centrifugal force the air out of the  tunnel along which the cars, drawn by suction, sped at a rate of thirty-five  miler per hour.</p>
<p><a title="Image4 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709718301/"><img class="alignright" src="http://farm3.static.flickr.com/2501/3709718301_5eaaf8566d_m.jpg" alt="Image4" width="159" height="240" /></a>The  tunnel as it stands to-day is made up of cast-iron sections in nine feet lengths  and nearly an inch in thickness. Each section was cast in one piece, and in shape resembles a “D” lying on its back, with a groove in the corners along  which the rails are laid. At the stations hermetically sealed spring doors  excluded the entrance of air, so that when necessary a vacuum could be produced  before the departing cars. The addition of an engine to revolve the hollow wheel  I have described completed the whole outfit of a scheme that was to  revolutionise the prevailing forms of carriage and general motion. In a <em>Times</em> leader of February 10<sup>th</sup>, 1863, I have found the following: “Between  the pneumatic dispatch and the subterranean railway the days ought to be fast  approaching when the ponderous goods vans which now ply between station and  station shall disappear for ever from the streets of London.”</p>
<p>Over thirty-six  years have passed, and the railway van is to-day more ponderous, ten times more  numerous and a hundred times greater danger to those who use the streets.</p>
<p><a title="Image5 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3710530070/"><img class="alignright" src="http://farm3.static.flickr.com/2567/3710530070_0c8b05c867_m.jpg" alt="Image5" width="240" height="183" /></a>And  yet we boast of our progress! Nevertheless, the journalists of those days  reveled in dreams of pneumatic enthusiasm; and schemes , that doubtless then  appeared well controlled and feasible, to-day are known to have been of the  wildest and most improbable. Listen to the exultation-cum-wailing of the <em>Seven  Days Journey</em>, a propos of the Pneumatic Dispatch Company, under date December  13th 1862: &#8220;We are fast making London a marvelous and unequalled city; and  if with-all-our improvements and inventions we could only devise some means of  rendering the three millions of dwellers in it safe from the murderous attacks  of garrotters and , burglars we should have just reason to be proud of our  smoke-covered, but unmatched, capital.&#8221;</p>
<p>Well, the smoke is still with us in  greater volume than of old; but the many-tailed cat has tamed the murderous  thief and the Pneumatic Dispatch Company, has been resurrected and is promised a  new life with electricity for its vital power.</p>
<p style="text-align: center;"><a title="Image6 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709719527/"><img class="aligncenter" src="http://farm3.static.flickr.com/2471/3709719527_b883e278b2.jpg" alt="Image6" width="500" height="191" /></a></p>
<p>Yet  another reference to &#8220;olden times,&#8221; and the dead past must give way to  the living present. <em>The London Journal</em>, in 1863, printed this piquant  paragraph: &#8220;Not only have letters and parcels been transmitted, through the  tube but we hear also that a lady, whose courage or rashness &#8211; we know not which  to call it &#8211; astonished all spectators, was actually shot the whole length of  the tube, crinoline and all, without injury to person or petticoat.&#8221;  Following on this came a multitude of proposals for pneumatic passenger  traction. A trial railway was laid at the Crystal Palace, and proved successful.  The Waterloo to Whitehall Pneumatic Railway Company was formed. Great Scotland  Yard was fixed upon as a site for one terminal station, and adjoining the  Waterloo Station in York Road the other. Excavating and tunneling were  commenced. The river was to be crossed in an iron tunnel resting in a dredged  channel across its bed. <em>The Illustrated Times</em> of August 17th, 1862 gave a  full-sized plate, showing the works in progress, and in accompanying letterpress  chimed that, &#8220;in its present form, the pneumatic system is simply an  adaptation of the process of sailing to railways, the wind being produced by  steam-power and confined within the limits of a tube.&#8221; Passengers were to  have perfect ventilation, no smoke (excepting tobacco), no steam, no jolting, no  vibration, no collisions and in fact none of the disadvantages more or less  attendant on any railway line in kingdom to-day. Although Messrs. T. Brassey and  Co. were the contractors for this ideally perfect railway line I cannot say  where it has disappeared to. Evidently it savoured too much of Elysium to be  allowed to remain on earthly shores.</p>
<p><a title="Image7 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3710531284/"><img class="alignright" src="http://farm3.static.flickr.com/2472/3710531284_dde099e402_m.jpg" alt="Image7" width="240" height="175" /></a>Many  persons, however, made the journey in the Pneumatic Dispatch Company&#8217;s cars. The  <em>Evening Standard</em> of April 5th 1868, mentions &#8220;Prince Napoleon and  his secretary&#8221; as being among the passengers, and an illustration on page  623 [image below] shows, the Holborn Station &#8211; which was located in close proximity to the  present Royal Music Hall &#8211; with a  departing car passenger-loaded. For this plate I am indebted to Mr. T. E.  Gatehouse, responsible editor of the <em>Electrical Review</em>, Fellow of the  Royal Society, Edinburgh, a member of the various Institutions of Engineers,  Civil Mechanical, and Electrical, besides being a well-known amateur violinist.  Mr. Gatehouse entered the service of the Pneumatic Dispatch Company in 1869 &#8211;  the days of his fallow youth &#8211; and scores of times made the journey through the  tube lying in the fast- flying cars. &#8220;The central station was in High  Holborn,&#8221; he states, &#8220;and contained the whole of the motive power.  Here the, cars changed from one set of rails to another and the time taken in  completing the whole journey from end to end was nine minutes. It was always an  exhilarating journey, the air being fresh and cool even on the hottest of summer days. From Holborn Circus where the tube dives clown a steep declivity  under Farringdon Street, the speed was about sixty miles an hour, and in the  darkness it felt as if I were sliding down a hill feet foremost.</p>
<p><a title="Image8 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709720623/"><img class="alignright" src="http://farm4.static.flickr.com/3506/3709720623_eae2fb0fc7_m.jpg" alt="Image8" width="240" height="149" /></a>The  impetus of this rush would carry the car up the incline to Newgate Street. To  me, who made the trip for the first time, there was something weird and uncanny  in being shot through a tube at a high rate of speed, so near the surface of the  roadway that the clatter of hoofs and the rumble of vehicles could be distinctly  heard, accentuated frequently by the tallow candle or oil lamp being  extinguished by the draught. I got so accustomed to the journey that I could  tell what corner I was turning. and the streets above precisely at any  moment.&#8221;</p>
<p><a title="Image9 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3710532342/"><img class="alignright" src="http://farm4.static.flickr.com/3436/3710532342_6b510e53a0_m.jpg" alt="Image9" width="240" height="189" /></a>After  a period of eight or ten years the Pneumatic Dispatch Company relinquished  operations. At intermittent times only had the line been worked; and quietly,  without fuss or flurry, as became the collapse of a gigantic scheme, the end  came and pneumatic propulsion on a wholesale scale received its death-blow in  the minds of experts. The insuperable difficulty lay apparently in the  impossibility of rendering the tunnel sufficiently airtight. Leakages of various  extents prohibited the creating of a working vacuum, and after the engine-power  had been increased until it attained six times its original strength, further  efforts were considered useless.</p>
<p>The  Company had been an extremely powerful one, with rights and privileges  guaranteed to it by special Acts of Parliament. Among the directors were the  Marquis Of Chandos, the Hon. W. Napier, Sir Charles J. H. Rich, Bart., Messrs.  W. H. Smith, Thomas Brassy, and others. Mr. John  Aird was the contractor for the line, of which Messrs. T.W. Rammell and J.  Latimer Clarke were the joint engineers.</p>
<p><a title="Image10 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709721715/"><img class="alignright" src="http://farm4.static.flickr.com/3515/3709721715_25132aaa1c_m.jpg" alt="Image10" width="240" height="188" /></a>It  was in 1895 that Mr. Thelfall first entered the disused tunnel after struggling  and squirming through a heap of <em>debris</em> and lumber in a basement of Euston  Station alongside Seymour Street. For many yards from the entrance of this  terminal there was a trough to allow of the air propelling a car to escape and  thus reduce the impacts on the receiving buffers. An incautious step upon the  rotten wooden platform here precipitated the unwary explorer into three feet of  stagnant water, but he nevertheless kept his ardour dry, and after several weeks  practically completed his inspection of the whole tunnel (excluding the platform  below Holborn Viaduct, which he found full of water), and decided that a fair  expenditure would put it in working order for the propelling of cars by  electricity.</p>
<p><a title="Image11 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3710533750/"><img class="alignright" src="http://farm3.static.flickr.com/2480/3710533750_4a5fb5d84a_m.jpg" alt="Image11" width="240" height="223" /></a>Having  discovered the tunnel and realized its effectiveness the still more difficult  duty devolved on Mr. Thelfall of finding its owners, the original shareholders,  or their heirs, together with the necessary plans and papers. It was indeed  strange that the mouth-open tunnel, separated from a busy street by merely an  iron railing and a few steps, should remain  undiscovered even by these of our community whose misdeeds or intentions force  them to hide from the inquisitive  glare of X2671&#8217;s bull&#8217;s-eye lantern and  the clink of his handcuffs. In the troublous times of 1883-4 when misguided  wretches were attacking with dynamite bombs London&#8217;s main thoughfares and  buildings, one shudders to think what the knowledge of the tunnel&#8217;s existence  might have led to on the part of these miscreants. Some dynamite, a line of  wire, and a battery spark, and the Nihilist, Anarchist, or Fenian might have sat in safety and ripped a tract of death and desolation throughout the  Metropolis. But there are no apparent signs that the tube was ever the  hiding-place of any human being. Merely a few, skeletons of rats and,  presumably, cats judging by the size &#8211; what a Homeric combat of &#8220;fighting  against odds&#8221; do these crumbling bones suggest ! &#8211; and here and there  umbrella-shaped fungi where the water condensation is greatest.</p>
<p><a title="Image12 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3710534422/"><img class="alignright" src="http://farm4.static.flickr.com/3472/3710534422_0cdfba5d42_m.jpg" alt="Image12" width="240" height="203" /></a>Stranger  almost than the loss of the tunnel was the disappearance of its owners and the  papers that would tell who they were. After eighteen months hard search in  Government offices and the five parishes through which the tube runs, Mr.  Threlfall realised that neither they nor the original contractors had a single  plan of the route. It was not until after a wearying system of inquiries half  over England and on the Continent that Mrs. Frances Rammell, the widow of the  late T. W. Rammell, a famous engineer, was discovered and, through her  remarkable energy, the original plans were eventually brought to light.</p>
<p style="text-align: center;"><a title="Image13 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709724067/"><img class="aligncenter" src="http://farm4.static.flickr.com/3428/3709724067_f088c35719.jpg" alt="Image13" width="500" height="320" /></a></p>
<p style="text-align: center;"><a title="Image14 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709725457/"><img class="aligncenter" src="http://farm4.static.flickr.com/3502/3709725457_793edc8bee.jpg" alt="Image14" width="500" height="464" /></a></p>
<p>To  realise the commercial value of the tunnel&#8217;s discovery and rehabilitation it is  necessary to have some slight idea of the extent of mails and parcels passing  not only between Euston and the G.P.O., but also between Eversholt P.O., the  other local offices en route, and the two main termini. Practically all the  heavy post to the north of Great Britain passes through Euston Station, and the  heaviest hour of the day sees a total of eleven tons of postal matter leave the  G.P.O. for the North-Western Central Station. At present vans carrying from one  and a half to two tons each, and taking twenty-four minutes under the  most favourable circumstances, make the connecting journey. Heavy traffic, fog,  greasy pavements, or other drawbacks to vehicular motion, may double the time  occupied. The contract time for the delivery of the mails to the various stations  is eight miles an hour, and the enforcement of this rate of speed is one of the  G.P.O.&#8217;s chief difficulties. For a time motor-cars were tried, but without  success. The road to Euston is perhaps the most difficult of all to make  progress along, and there is no doubt the tunnel, when fitted will be an  enormous convenience to the postal authorities.</p>
<p><a title="Image15 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709726065/"><img class="alignright" src="http://farm4.static.flickr.com/3500/3709726065_c33cafd068_m.jpg" alt="Image15" width="240" height="211" /></a>When  the tunnel is ready, a copper strip will be laid in a trough between the rails,  from which an electric-motor drawing a maximum load of seven cars, will pick up  the electric current by a roller contact. The current will be supplied by the  electric lighting companies and there will be therefore no initial expense for  setting up a generating plant. About forty miles an hour, or under two minutes  for the journey, will be the highest speed to be attained; and as each car will  carry a ton of mails or parcels, seven tones will fly from post-office to  station in a twelfth of the time taken by so many horses and vans. There is  nothing chimerical or &#8216;extravagant in Mr. Threlfall&#8217;s scheme. The highest  experts have endorsed it, and a firm of railway contractors, and also of  electrical engineers, now have the preliminary work in hand, on their own  stipulations that not a penny is to he paid them should the line-prove a  failure, and in consideration of shares and debentures in the new company &#8211; the  London Dispatch Company &#8211; being allotted to them.</p>
<p><a title="Image16 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709726845/"><img class="alignright" src="http://farm3.static.flickr.com/2559/3709726845_7bb6c878f1_m.jpg" alt="Image16" width="240" height="210" /></a>Given  the success of this electric postman with all restraint of enthusiasm it may be  hinted that Paddington, Waterloo, London Bridge, Charring Cross and Victoria are  likely to have similar connections to the G.P.O.</p>
<p>Realising  the possibility of this and remembering the many journeys made by passengers on  the pneumatic railway, it does not seem audacious to imagine high officials or  other prominent personages availing themselves daily of this rapid route between  the City and the stations, until finally the mails and parcels are relegated  once more to the vans and the tunnel devoted wholly to passenger traffic at  saloon charges.</p>
<p style="text-align: center;"><a title="Image17 by IanVisits, on Flickr" href="http://www.flickr.com/photos/ianvisits/3709727339/"><img class="aligncenter" src="http://farm4.static.flickr.com/3447/3709727339_7126f01019.jpg" alt="Image17" width="500" height="402" /></a></p>
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			<wfw:commentRss>http://www.ianvisits.co.uk/blog/2009/07/11/londons-lost-tunnel/feed/</wfw:commentRss>
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		<title>Jubilee Line tunnels under Big Ben</title>
		<link>http://www.ianvisits.co.uk/blog/2009/05/31/jubilee-line-tunnels-under-big-ben/</link>
		<comments>http://www.ianvisits.co.uk/blog/2009/05/31/jubilee-line-tunnels-under-big-ben/#comments</comments>
		<pubDate>Sun, 31 May 2009 14:06:13 +0000</pubDate>
		<dc:creator>IanVisits</dc:creator>
				<category><![CDATA[subterranean stuff]]></category>
		<category><![CDATA[big ben]]></category>
		<category><![CDATA[clock tower]]></category>
		<category><![CDATA[houses of parliament]]></category>
		<category><![CDATA[jubilee line]]></category>

		<guid isPermaLink="false">http://www.ianvisits.co.uk/blog/?p=1282</guid>
		<description><![CDATA[A few months ago, I went to a lecture on tunnelling technologies, given by  Professor Robert Mair FREng FRS, and specifically on what is known as  compensation grouting. Meant to write up about it at the time, but it was not  the sort of talk that was easy to write about, as [...]]]></description>
			<content:encoded><![CDATA[<p>A few months ago, I went to a lecture on tunnelling technologies, given by  <a href="http://www-g.eng.cam.ac.uk/125/now/rjm.html">Professor Robert Mair FREng FRS</a>, and specifically on what is known as  compensation grouting. Meant to write up about it at the time, but it was not  the sort of talk that was easy to write about, as the core of the talk needed  the slides to illustrate what was being talked about.</p>
<p>However, the <a href="http://royalsociety.org/">Royal Society</a> &#8211; who  hosted the talk &#8211; put podcasts of their lectures on their website, and today I  finally got round to reviewing the details (mainly as the podcast page only  works in Microsoft browsers!).</p>
<p>Today, I am going to focus only one aspect of the talk, which was also one of  the more famous instances of compensation grouting, and that is the Jubilee Line  work around the Clock Tower, more famously known as Big Ben. Timely, as the  Clock Tower is 150 years old this week.</p>
<p><img class="alignright size-full wp-image-1284" title="image14" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/05/image14.gif" alt="image14" width="185" height="252" />As a Jubilee Line tunnel was tunnelled by the tunnel boring machines (TBM), despite  the best efforts of the workers, there is always a slight gap between the tunnel  wall and the soil outside, leading to some subsidence at ground level. The gap  is only a few millimetres, but when amplified around the entire tunnel diameter,  that actually adds up to quite a bit of missing soil, and can cause significant  problems. Before work starts on any tunnel now, ground surveys and measurements  are taken to calculate the subsidence risks and effects on buildings.</p>
<p>In some areas, where the tunnels are likely to cause significant problems,  compensation grouting is used.</p>
<p>This is basically steel pipes that are drilled into the ground above where  the tunnel is due to be dug &#8211; before it arrives &#8211; that pump in a slurry type  concrete mixture into the ground to &#8220;compensate&#8221; for the missing soil  below.</p>
<p>For the Jubilee Line, this was complicated by the architecture of the  location and the fairly shallow foundations of the infamous clock tower. The big  risk, which was gleefully latched onto by the news media was that the tower would start to  lean sideways towards the tunnel work and may even start to develop cracks or  damage. As the TBM worked its way through Westminster, electronic monitors on  the tower checked how far it was starting to topple, and then pumped grouting  into the soil to basically push the tower back upright again.</p>
<p style="text-align: center;"><img class="aligncenter size-full wp-image-1285" title="image11" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/05/image11.gif" alt="image11" width="550" height="414" /></p>
<p>The compensation grouting was only carried out at night &#8211; as the hole in the  ground where they worked was right in the middle of the road, so covered during  the day to allow road traffic.</p>
<div id="attachment_1288" class="wp-caption aligncenter" style="width: 560px"><img class="size-full wp-image-1288" title="image10" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/05/image10.gif" alt="At night the grouting machine was lowered into the hole, shown by the yellow circle." width="550" /><p class="wp-caption-text">At night the grouting machine was lowered into the hole, shown by the yellow circle.</p></div>
<p>The pipes drilled reaching under the ground were on average 60 meters in  length. The black circles show where the grouting was inserted &#8211; and  on  average about 150 litres of cement grout was pumped in at each point.</p>
<p><img class="aligncenter size-full wp-image-1286" title="image9" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/05/image9.gif" alt="image9" width="550" height="412" /></p>
<p>The following slide shows the movement of the tower. They knew the tower  could withstand about 15mm of movement, measured at the height of the clock face, before action was needed &#8211; and you can  see here how the tower started tilting, then a period where the compensation grouting  was applied and after tunnelling, the period where the tower more slowly (and  safely) settled.</p>
<p style="text-align: center;"><img class="aligncenter size-full wp-image-1287" title="image7" src="http://www.ianvisits.co.uk/blog/wp-content/uploads/2009/05/image7.gif" alt="image7" width="550" height="411" /></p>
<p>Incidentally, the tower was already leaning before the tunnelling work started &#8211; by about 22cm to the North-West, which is said to be just noticeable to the eye.</p>
<p>Without compensation grouting, it is expected that the tower would have tilted by some 10cm at the top &#8211; which would have been obviously unacceptable.</p>
<p>&#8211;</p>
<p>The sides are taken from the podcast on the <a href="http://royalsociety.org/page.asp?id=3093">Royal  Society</a>, where you can watch the entire lecture. Note, the slides wont  display in either Firefox or Chrome web browsers &#8211; so I had to use MSie to watch  see them.</p>
<p>I&#8217;ll later do a write up about the work at Kings Cross as some aspects of  that sound quite interesting, but needs more research work to be carried out.</p>
<p>Incidentally, if you want to climb up the Clock Tower,  visits are fairly easy to arrange &#8211; a review of the <a href="../2008/11/11/visiting-big-ben/">details  here</a>.</p>
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