|
Post by railtechnician on Aug 18, 2016 1:04:40 GMT
I have looked a few more times and appears to me that the guy is either holding the wheel for the photo or is operating it and I think it may be a valve? Yes it will probably be a valve operating wheel, he is probably checking either that it is free to be rotated or that it is secured although I noticed no chain and padlock. What it actually does is another question. I expect it maybe to allow accumulated water, say from a NPA subway or a chamber to drain into a sump from which it will be automatically pumped. Keeping stations dry is a tricky business, especially the deeper ones which are generally wet at the lowest levels most of the year such as the Northern, the south end of the Bakerloo and other places such as the shallow Picc between Hounslow West and Hatton Cross. Remember that water can only be pumped vertically 32 feet and then it has to be pumped again so drainage from one chamber or sump to another is not uncommon. In places like Liverpool Street the escalator LMC sump used to pump the water out to the platform inverts whence it was pumped again once the level had risen enough to start the invert pumps. At stations like Piccadilly Circus the Bakerloo inverts were permanently flooded and at Arsenal the water in the invert was generally four feet deep. Embankment Northern was very wet, Finsbury Park too and of course most of the old East London Line where the pumps never stopped unless they were faulty.
|
|