Incidentally, that should say 5172 and 5196; the units are numbered from the even cars upwards with the first unit built being 5000 - 6000 - 6001 - 5001 and so on.
A stock trains are formed of 2 four car units, with cabs at each end, during the refurbishment (AFAIK) on the met line trains only 1 cab in each unit was refurbished, and the units were hence made to single cab, and 2 units are permanently coupled back to back.

Actually, it seems that there is now a train shortage on the Met (due to the A stock not being as reliable as it was, possibly caused by Neasden not looking after them properly as they are about to be replaced), so I don't think any more units will go until S stock can be used on normal services.I guess there's been an excess of A-Stock since the ELL closed for conversion?
It was when they were converted to OPO in the 1980s, not all cabs were converted to have door controls. Two units in a train aren't 'permanently coupled'. The 'inner end' cabs are still used for shunting, and single ended units can run out of service on the line on their own. This sometimes happens when a unit has to be turned on the Watford triangle. Before conversion to OPO, the A stock was reversible (you could couple two 'A' ends together). In fact, a unit once ran formed of cars 5042-6042-5043-5056.A stock trains are formed of 2 four car units, with cabs at each end, during the refurbishment (AFAIK) on the met line trains only 1 cab in each unit was refurbished, and the units were hence made to single cab, and 2 units are permanently coupled back to back.
There are still "reversible" units (capable of running as single units) within the fleet, aren't there? For the Chesham shuttle service and ex-ELL?
Slightly off-topic for this thread I know, but does anybody know what has caused some of the 'A' stock to be out of service today, and is it likely to be a long term problem ?
Apparently in the case of the Met it's the current RMT/TSSA overtime ban messing up routine maintenance.
I didn't know we used classes on the Underground...
If you read the stickers you will find out it is a test train, and has computers etc inside.
The train was there, because, shockingly, the S stock is going to go everywhere on the Met one day, and from yesterday can go anywhere apart from Chesham - Chalfont and Baker Street - Aldgate.
"We" as in London Underground staff, ex-Metronet staff, ex-Tube Lines staff, Various public HMRI, Government, Network Rail and National Rail publications, train enthusiasts and anyone else do not use classes on the Underground, just the same as on National Rail we don't call a class 378 "2009 Mainline Stock":roll:
Your missing the point. I admit I made a mistake. However when you use the term 'we' in reference to an organistation such as London Underground, it makes it seem as if you were part of that organisation, which you are not :roll:![]()
Indeed, although last I knew the D stock replacement had been put on hold due to lack of £££. C stock replacement will follow the A stock with the same trains with minor differences such as one less car and less seats.

Yes, S8 is 8-car stock for the Met line only and S7 will be 7-car to replace the C and D stock on the District and Circle and Hammersmith lines.Anyway back to the original topic. I heard LU 'S' Stock will also eventually replace the District line and Hammersmith & City line stock?
Before reading your post, and whilst reading Gavelexs, I did not find Gavelex's post to be as if they were claiming they were LU staff at all myself.
Anyway back to the original topic. I heard LU 'S' Stock will also eventually replace the District line and Hammersmith & City line stock?