After a few weeks of lockdown silence, life is returning to Crossrail as test trains have started running through its tunnels once again.
As with much of society, Crossrail had to adapt to a sharply different world in the age of the virus, and while it looks as if work came to a stop, in fact, a lot of work has been going on since the lockdown started, and several important milestones achieved.
All this with minimal staff in the building sites themselves, and that’s in part thank to the stage the construction work is at today with most of the heavy-duty work completed, but in part also thanks to how modern railway infrastructure is designed to work these days.
Had the lockdown happened a few years back, then it would have been far worse for the project. While it’s not that difficult to safely down tools, it’s quite difficult to get started again as often construction sites run to tight schedules with deliveries agreed months in advance. Also, highly specialised equipment can have booking schedules that means a very long delay if you need to rebook them.
Fortunately, the tunnel boring machines long since finished their work, as getting one of those restarted if it had to stop while drilling a tunnel is a nightmare.
Of course, the Crossrail project should by now have handed over to the Elizabeth line, and carrying the few people allowed to travel on trains to work. But that didn’t happen, and there’s still a lot of building sites where there should be live train services.
So what’s going on at the moment?
Not too much at the building sites at the moment, which are now less huge holes in the ground than a warren of corridors and cramped working spaces not at all suited to social distancing.
What’s going on though is a lot of the assurance paperwork that needs to be completed to show to the railway and safety regulators that everything is indeed where it should be and doing what it should do.
As explained by Crossrail’s Technical Director, Colin Brown, as with most companies there’s been a huge shakeup in how they can work, but modern working practices now make working from home, on a construction project not just possible, but as most of us are learning, in some situations, better.
This has surprised some, as people working in the railway industry can sometimes be somewhat conservative in dealing with new things – an asset when handling safety-critical systems – but not so useful when asked to do a file transfer then jump into a Zoom meeting and then Whatsapp the details to Microsoft Teams.
Many of us home workers have adapted to video calls, with some degree of success, and I am sure we’re far more familiar with close-ups of many co-workers double- chins than we ever expected to be. It’s also unlikely that there’s anyone now who hasn’t had a video call end at least once in the past few weeks with someone saying they’ll send over the files, when their teenage kids show them how to.
While there are downsides, a lot of people have reported that meetings tend to be shorter over video links. The 45-minute lockout on free Zoom calls was recently described as the greatest aid to productivity ever. And for an organisation with lots of sites, such as Crossrail, not having to wait until everyone is back in the office to hold a meeting speeds up processes considerably.
Those processes in question being the completion of nearly 200,000 documents to assure some 500,000 individual assets before the railway can be approved for passenger use. It’s checking that cable management, lighting systems, communications, signalling, fire systems, and many more all comply with safety regulations.
As each section is certified, then they can be handed over to TfL.
To do this, very early on in the project, Crossrail invested heavily in a document control platform known as eB, and this has proven not just useful in normal times, but critical now with around 2,000 staff working remotely as it has helped smooth the document certification process.
When Crossrail’s Technical Director, Colin Brown looks at what he calls the trends, how much work is being completed on time, he said that he can barely notice the day that working from home was imposed on the team. Like many other companies, there was about a week of shock at what had just happened, and ironing out the problems of getting IT systems to work from home and the like, and then it’s back to work as normal.
Remarkably, while it’s still far too early to be certain, even with remote working, the lockdown has not had a massive impact on this element of the progress to get the Elizabeth line operational.
There was also a stroke of luck in that a huge paperwork submission they had been waiting for, known as the engineer’s safety justification for the tunnels arrived just before the lockdown, giving people working from home plenty to get on with.
Crossrail also introduced a process they are calling niche working, so where some tests weren’t carried out correctly on site, or the necessary paperwork not completed, they have small teams who can safely enter the stations to complete the work, run the tests take photos, and they can push the assurance process onwards.
Restarting the building sites
Those slumbering sites are starting to wake up now.
For all the size they seem to take up in cities, anyone who works on one will tell you they are often cramped places to work, and no less in the welfare spaces where offices, toilets and canteens are provided. Additional cabins are being added to some sites to help spread out the workers, and at the stations, some of the ticket halls have been converted into enlarged welfare sites for the construction workers.
The tunnels that will one day throng with passengers are also fortunately so wide that it’s been possible to put wide barriers down the middle and let staff back on site while keeping them safely distanced.
Although they’re able to make the building sites safe for socially distanced working, one problem is safely getting staff to and from work, without putting pressure on the public transport network, so they’ve been working on how to provide staff travel services.
The Elizabeth line’s very first “replacement bus service” could be the one used to get the construction workers to work in the mornings.
All this preparatory work enables the final stages of the construction to get started again, and the additional checks when needed for the paperwork assurance to be carried out.
Some of the assurance tests may surprise you. The railway decided early on to rely on LED lighting throughout, which sounds perfectly sensible, but the assurance paperwork was designed for an era of fluorescent tubes and incandescent bulbs. The paperwork simply didn’t exist to approve the use of LED lighting, so a lot of work went into testing LED lights to prove what seems obvious, that they are safe to use.
Issues such as panels not quite lining up as they should, little finger traps that need filling in, cameras not quite seeing all they were expected to see — the things we would never notice but are quite important and need to be fixed before the line can be fully certified for passenger use.
In addition to ensuring that the railway complies with safety regulations through this process, they’ve also been using the time to write up all the maintenance manuals, so that long after the last construction worker has hung up their hard hat, the railway can be looked after.
Getting the trains running again
However, this weekend, one of the biggest restarts took place – testing of the trains.
This had to be paused when the country went into lockdown, as some adjustments had to be made to the train cabs as they need to have two people in them during testing and driver training, so separator screens now run down the middle, and the second seat had to have a new stop plunger added to their side of the cab in case it’s needed to stop the train in a hurry.
Not everything stopped though.
Crossrail has an off-site team based in Chippenham where they test the software that will eventually control the trains on the live service. The staff there are still at work during the lockdown – with two staff in a now very empty office, and 60 more working from home refining the train software systems and running simulations.
Some systems which were typically hardware-based, such as the Control Centre Workstations which give staff an overview of the railway and signalling have been quickly adapted to allow staff to remotely access them. The same approach was taken to the testing regime where they run simulations of a fully functioning Elizabeth line.
That has resulted in the slightly surreal effect for people who do go into the Control Centre of watching the big screens busily jumping between different systems that are switching on and off, even though the room is empty.
A lot of this is possible due to changes in how trains are developed over the past 10-15 years, with software teams working in several countries all able to collaborate and make changes remotely.
An Elizabeth line train will have a train control management software from Germany, that’s then modified for Crossrail by Bombardier in Derby. In addition, there’s the European Traffic Management System, written in Stockholm, the Communications-based train control (CBTC) written in Paris, and they are all bought together in Chippenham.
So what they can do at the moment is software development and simulations.
It’s not been plain sailing, with the occasional office having to close at times, and once a server couldn’t be rebooted unless someone went into an office to turn it off and on again, but considering how work would have ground to a complete halt just a decade ago, the current situation has been a revolution in train development.
The big problem with simulating the sophisticated train control systems used today is that they often work perfectly in the laboratory, but then fail when tested in the real world. That lab to real-world problem is why it can take sometimes many upgrades of the software to iron out bugs or develop fixes before a train can be certified as safe to use on the railways.
Crossrail has the added complexity of needing to handover, at speed, between three different signalling systems.
The core tunnels use a Communications Based Train Control (CBTC) signalling system which is similar to that used on the Jubilee, Victoria, and Northern lines and DLR, and allows for automatic train operation in the tunnels.
The western section out to Heathrow uses the European Train Control System (ETCS), a digital ‘Moving Block’ signalling technology that will be rolled out across the UK’s rail network. The line out to Reading in the west, and from Liverpool Street to Shenfield in the east uses AWS / TWPS, an older ‘Fixed Block’ train protection system still used throughout the UK.
However getting all those systems to talk to each other, and the trains — reliably — has been a challenge. Anyone who has ever worked with radio systems or cabling in industrial areas, and with lots of high voltage mains supplies knows that the laboratory and the real world rarely align.
An example last year, the trains could switch systems when heading west, but couldn’t hand back when travelling east. Trains could go to Reading, but not come back to London. A software patch later, and that problem was solved, and on to the next one.
Frustratingly for the Crossrail team, they were probably not much more than a month away from completing this stage of dynamic testing before the lockdown hit.
Although testing in tunnels was paused for a couple of months, Bombardier was able to start running some tests, at their above-ground test track at Old Dalby a few weeks ago once they adapted their facilities for spaced out working.
All those works build up confidence that the trains are fine, but that still needs testing to take place in the tunnels, and a major milestone was achieved this weekend, when Crossrail was able to resume running trains again.
What they’ve restarted is the final stage of Dynamic Testing. What comes next is the intensive trials to simulate the full railway service, known as Trial Running.
To do that also needed the stations to be completed to a level that would if needed, allow for the drivers and any staff on board the trains to leave via the station. Having train drivers wandering around an unfamiliar building site looking for the exit is not ideal, and not allowed anyway – so each station needs to reach a stage of completion where the evacuation facilities are fully working.
With the stations now ready, Crossrail expects to complete Dynamic Testing fairly soon and then it can move to full Trial Running through the tunnels — effectively simulating the live railway.
They need to run a live service without passengers for hundreds of hours to prove the live is safe, and then they get their certificate to take on passengers.
Before the lockdown, there was a split between works in the stations and the train testing, as it’s not viable to do both at the same time if you have engineering trains delivering to the stations. That allows both sides of the operation to progress, but slowly, and there is some thought being given now to a large block of time being booked out just for train testing to get it done and dusted.
Oddly, that’s only been possible thanks to the lockdown forcing a live testing pause so lots more software testing could be carried out and it also gave the teams time to plan their work more effectively.
Elsewhere, works are progressing where possible, and a couple of weeks ago, little-noticed, there was the formal handover of Custom House station by Crossrail to TfL. The paperwork was completed, all the signatures applied, and in normal times, there would have probably been a bit of a ceremony at the station.
As it was, an email had to do the job.
At the moment, the full impact of the lockdown on the Crossrail project is unknown, mainly as it’s still unknown when society in general will be allowed to get back to work normally again. So while it’s likely that there will be a delay, because they’ve been able to work remotely on so much of this stage of the completion works, the delay wont be anything as bad as it could have been.
The next year or so probably isn’t going to be much fun as the world recovers from the coronavirus — but there’s something to look forward to, the opening of the Elizabeth line.
Article last updated on May 19th, 2021 at 08:25 am