Circle Line stock, 1971

Externally I can't think of any other difference, however the internal differences were more obvious, the main being the guards controls were in the cab of the O stock similar to the unrefurbished C stock, with the guard working the doors from the rear drivers cab.

I love pictures of CO / CP / R stocks as well ... more please !

Internally another obvious difference between a CO and a CP was the transverse seats on a CO had tall seat backs, where as a CP had more conventional seat backs coming up to the bottom of the window level. Not sure about a COP trailer though ? Did they match the type they were formed with ?

However thanks to Hindenberg for the long list of differences to the car exteriors ! I'd never have spotted all them !

I'm curious as to why was there no exterior butterfly cock on a CO DM ? How were a set of doors opened in an emergency ?

Maybe the logic was that passengers could be detrained via the cab? Pure guess, though!

All CO trailer cars had the transverse seat backs up to the bottom of the window level as in the CP design.

Yes,basically traction current from the pick-up shoes comes in one end of the machine and it puts out a voltage the other end to work the traction motors,apparently it gave very smooth acceleration but it wasn't very reliable and the system was very complicated,all metadyne machines were removed from the O & P stocks in the mid 50's leaving just a couple of battery locos fitted,these were scrapped in the early 70's.

No, actually, at the time this photo was taken, trains on the Circle were numbered 211-217 inner rail and 201-207 outer rail and they still are. The three normally stabled at Farringdon are all inner rail starts so they all have 21x numbers. The night chargehand fitter there used to set up the train numbers ready for the morning. He only needed to get a call from the foreman at Hammersmith to tell him which train was to get which third digit. That's why you can see 21 + blank on each train. By the time we arrived in the early mornings to prepare our trains he had put the full 3-digit number on the end of each train so we knew which one was ours.

The above mentioned chragehand ran a meat market stall at Romford during the day and got his meat from the Smithfield Market round the corner from the station. He offered us crews meat at good prices too. I remember he did very good sausages. I expect that sort of thing is banned by the EU now.

You've got a great collection of shots there Geoff..well done. I like the mix of old and new. It's interesting to compare these 1970's shots on the Underground with what was happening on the New York Subway at the time. From the Joe Testagrove collection on nycsubway.org graffiti started over there as early as 1968...by 1971 it was looking really trash but not quite how it looked by the early 80's. Anyone whos ridden Rome's metropolitana will know how bad it was...