Monday 20 December 2010

Air is not only essential to humans it’s also very important to trains. The doors and brakes are operated by compressed air, the whistle and the windscreen wipers too though obviously not as vital. Central Line trains, 92s, are made up of four two-car units and one car in every unit has a compressor. With every compressor there is a governor which monitors the air pressure and the whole system is linked throughout the train by pipes so if a compressor on one unit isn’t working the governor can start the compressors on the other units to feed it’s tank. This will be important later.

Monday was meant to be very simple; LES to EPP, EPP to WER, WER to LES, grub, then repeat and go home. To start with my first train was running ten late and when I relieved the TOp he explained that he had a governor stuck in which meant that all the compressors we running at full whack. Obviously if they are constantly working they will eventually overheat and then things get all flamey and generally unpleasent so he’d isolated it and a train technician should catch up with me on the way back. They never did.

As I headed up to EPP Wood Lane informed us that a train at HOP EB had suffered a mainline burst, the pipe that connects all the air tanks. This is a very bad thing because without air pressure on a pair of switches we cannot get the brakes off on the unit with the burst, so we have to isolate it from the healthy units, turn off the compressor and governor so we can empty the compressed air tanks to get the brakes off.

At the same time the air pressure holds back the Emergency Spring-applied Brake, a bit like a hand brake, so this will jam on once all the air is bled off. When we do get moving we have to drag the train through the brake pads, making progress very slow. All in all mainline bursts are considered to be the worst defect that you can suffer.

The absolute worst is a mainline burst on the lead unit as without those the pressure switches I mentioned earlier you cannot get the train moving, so you either need a train behind to push you along or another TOp will be ferried to the back of your train and they will drive in reverse while you instruct them from the front. And the computer was telling the TOp at HOP that the burst was on the lead unit. Not good.

Anyway I got away WB at EPP only a few minutes down and was expecting to be turned around at MAA but when I got to LOU Wood Lane announced that there had been a second mainline burst, this time on the WB between LEY and STR. Now thankfully MLBs are rare so to have two in the space of thirty minutes was incredible and I’m sure I was not the only TOp wondering if it was something to do with the weather and praying that I would be next.

I was held at LOU for a while, then moved up to WOO before being cleared up to SNA and then we got very lucky. The MLB at HOP was actually on the coupler between the first and second units, not on the first unit itself, which mean that the pressure switches were working and the train could move as normal. While I was making my way to SNA we got the all clear at LES-STR too so I guess that was a similar situation; a bullet dodged.

Regardless of our good fortune I was running 20 minutes late by now but Wood Lane decided to “stock and crew” me at SOR. I pulled into the WB platform, another train pulled into the EB platform, we swapped trains, I changed the number on the train I got on to the number of the train I’d got off and hey presto train 666 and it’s driver are back on time. My lunch break was saved.

Except I’d not reached NOR EB before I got a call from Wood Lane asking me to check the id number of my rear car. When I confirmed this the Line Controller informed me that the DDM at the depot did not want that train going through the pipe (I was never told why) and I should turn it around at WHC. As I was due to get off for my meal relief at LES in less than an hour the LC said they’d call WHC and get a spare to take me off. Sadly there were no spares available so there was no choice but for me to take it back to RUG and stick it in the yard which would naturally mean that my meal break and my second train were going to be messed up.

Anyway I got as far as SOR before there was yet another “next platforms and hold” call for a points failure at WER so when I should have been making myself a cup of tea I was sat on the front of a train staring at a red signal. Ten minutes later we got the all clear, I tipped out at RUG, stabled the train and walked out of the depot. I presented myself at the DMTs desk for instructions 30 minutes before I was due to pick up my second train at LES, obviously that wasn’t going to happen especially as my second train had been put away in the sidings at LOU.

I jumped the next available train back east and finally got to LES around the time I should have been leaving there for my second trip up to WER. By the time I had my meal break the line was running smoothly but due to the lack of stock available my train didn’t come back into service until after I’d finished. What really made me laugh in all of this was while I was closing the train up prior to going into the depot the automated PA at RUG was announcing that there was a good service on the Central Line which was at the very least woefully optimistic.

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