As part of my day down at Chatham Dockyard, which I will write about in a day or two (as I am too tired right now), we went inside a submarine!

In a dry dock is HMS Ocelot, an Oberon-class diesel-electric submarine which put to sea in 1964 and was operational throughout the cold war until 1991 - when nuclear powered submarines suplanted them in their entirity.

When the submarine was decomissioned most of the radar kit was removed, presumably as it is still sensitive, and even to this day its sea missions are still classified.

It is incredibly cramped in there - nothing you have ever seen on a movie cannot prepare you for how utterly claustrophobic the place is. The humans are slotted in to the submarine, almost as an annoying afterthought.

Considering that there are nearly 70 people in this tiny space, one thing which surprised me is how “mechanical” the interior is with pipes, handles and switches all over the place. Quite how they didn’t keep switching things off by accident when trying squeeze past each other is beyond understanding.

Oh, and thanks to the lack of space, each sailor was permitted just one change of clothes for an eight week patrol.

Week one, underpants front to back - week 2, swap to back to front. Week 3, inside out front to back then week 4, swap around to inside out and back to front. Week 5, switch to spare undies and repeat the process. On sponge wash per week, if you are lucky.

As you can imagine - it stank in there, but as everyone smelt the same no one actually noticed.

It was a quite facinating tour - and the tour guide was good without being patronising about dumbing down (our group had no kids, which probably helps!).

Loads of photos at the usual Flickr location.

As I said, I was down there for a whole day - and we were getting a “behind the scenes” tour - which I will write about later.