COP Stock

[Alexh]

Hi Q8 and all,

I have been in the co/cp stock cab in the London Transport Museum, and the cab strikes me as ok but for one thing, the weight on the Deadmans Handle. How did you keep that down all day? Also were they very noisy things to drive, and what was the acceleration / braking up to much on them? I have heard that an R stock speedo was a vertical glass tube with fluid going up and down to show the speed, is this true and did COP stock have the same?

I so wish I'd been around to see all this for myself.

Thank you Q8, the threads have been interesting and informtive as ever.

[igelkotten]

As a bit of an international comparison, here are two pictures of the cab from an old C4 stock car from Stockholm. They were built in the early to mid sixties, and are all now scrapped,by the way.






As you can see, we also used to have the old coffe-grinder handle, which had to be depressed at all times. If you let go of the handle, without having applied a full service brake, you went into emergency. And while the handles were supposed to have a sort of latching mechanism, requring less pressure to keep them in position once they had been depressed fully, that one did not exactly work as planned. These cabs were responsible for a lot if repetitive strain injuries and other workplace injuries, and the stock was relegated to running as middle cars in trains, with other stock leading, for quite some time before they were scrapped. The handles had three very distinct nothces for power, and a fourth coasting position.

The grey handle on the right in the picture is the (removable) brake handle, which you had to carry along with you. Cast iron, about 1kilo. Good for imposing a bit of order on unruly passengers In the picture, it is in the "cab activate" position. The full release/running position would be more or less parallell with the front windscreen.

These units, like the CO/CP stock Q8 describes, never had a speedo, so you had to rely on your judgement. Indeed, while trains were fitted with speedos from the early seventies onwards, they were always considered a non-safety critical device, and were formally not required to work. This changed with the changeover to ATP signalling on the green line, since the ATP display is incorporated in the speedo.

Now, we have always run on a cab signalling system, with the old-style display being mounted on the cab wall above the controller handle in the second picture. This display, as well as a very loud bell and buzzer, told you the maximum permitted speed for a particular section of track.

On newer stock, the train automatically applies a full service brake if you don't bring your speed within these limits within a few seconds. On the old stock, C2-C5, things were a bit different.

If you oversped into a section with a lower permitted speed, you got a warning bell. You then had about two-three seconds (depending on the condition of a time/magnet relay) to apply full service brake, zero the controller and kick an "cab signal acknowledge" pedal located underneath the driver's desk, in a maze of air piping and electrical cabling. And even then, if the (notoriously rubbishy) brakes didn't reduce the speed sufficiently within a few seconds, you would still end up with an emergency.

Of course, to make things even more fun, the tachogenerators providing the speed sensor input for the cab signalling system and their calibration varied from car to car. What one car decided was 45 km/h could be sensed as 52 km/h in another. And the time relays were also quite eccentric. And, since these cars were on their way out when I started driving them, the driver's brake valves weren't exactly well calibrated, either. It was very easy when applying full service brake in a hurry to "go over the notch" and end up with the handle in emergency and all the air dumped with a mighty bang that left your ears ringing.

In other words, driving C4:s gave you very strong incentives to learn exactly were all the code change points along the lines were, and certainly improved your kick with the right leg. And gave you a permanently bruised knee, too. But oh my, how zippy the C4s were when you got a good train and didn't have to stop for the forseeable future.


/Igelkotten, sometime speed demon.

[Deleted]

An excellent question, AlexH, and two superb answers! We drivers/operators/motormen have it easy these days compared with how it was!

Did you ever drive a D78, Q8 or were you away by their introduction? Must have been quite an improvement in working conditions when they were introduced!

[Alexh]

Thank you Q8 and Igelkotten that was very interesting reading, I never thought COP's would be as bad as that, especially the part about an emergency brake application which only left the last car the station. Those C4's in Stockholm don't sound too clever either. The cab certainly looks grim. If you were born in a later age (1982 in my case) and never saw these trains in service you get an impression from books and talking to people that 'the old days were the best' and the trains matched. As Q8 says, this was not always the case and as AlanL says, I can imagine things are easier today.

Thanks for the excellent replies, they've been really helpful

[igelkotten]

Q8 said:

Seeing Mr Igelkotten's picture of the T Bana cab it seems to be a cross between a CP and Q stock. The controller handle on a COP was EXACTLY the same as the one pictured and with all the paraphinalia stuck here there and everywhere is reminiscent of the old Q's.

Tell Me Mr I were the camshaft controlled trains or notching relays accelerated?

Camshafts? Camshafts?!?

That's for weaklings! ;D

Actually, most of our stock used Westinghouse-style electropneumatic contactors for traction/brake control. A fridge-size box with a long row of pneumatically operated 700 V contactors, switching the motors and resistance circuits in and out.

This was used in various incarnations, from the old C1-C2 stock used from the very beginning in 1950, to the C4 from the mid sixties. The C4 contactor differed a bit from the C2 contactor, though, having a larger number of contactors and thus finer control over the notching up and down. That also made their running in mixed trains with C2 stock an interesting experience, since their running characteristics -especially on braking- were different.

From the early seventies, camshaft control was introduced with the C6 stock. The camshaft in question was a GE (the US company) construction, modified for local conditions, and using an electric motor for the camshaft operation. Incidentally , this means that getting a C6 that has run down it's batteries to opearate again is a rather hair-tearing affair. Camshaft control was also used for the C8 stock, a slightly evolved C6. The first use of camshafts were the very innovative experimental C5 stock, but they never led on to a series order, and ran as an odd 8-car fleet until thier scrapping in the late ninties.

At the same time, experimentation was started with thyristor control on the C7 and C9 stocks.

Due to budgetary constraints, when the C2 stock started getting old, they were not replaced by new trains, but rather with "refurbed" trains, the C12 and C13 stocks. They recieved a new carbody of the C6 type, but kept the traction control and certain other components from scrapped C1-C3 cars. In the case of the C12, they also reused old bogies. The C12 were delivered from 1976-77 to early eighties, the C13 in the early eighties. All C12-C13 are now scrapped, with the exception of a few C13 transferred to the infrastructure company and used for snow clearance operations.

From 1985-86, new thyristor controlled cars of C14 and C15 stock were delivered. While the C14 were officially classified as refurbishments of old cars, thus ending up under maintenance in the budget, rather than capital expidentures, they were in reality new cars. They are still in use, on the red & blue lines.Most of them are now refitted for operations on the ATP signalling system used on the green line, since that is were they were allocated up until a few years ago.

At about the same time, four cars of experimental C14z stock were delivered, using GTO thyristors and one of the earliest examples of asynchronous traction motors. Scrapped in the late ninties -very odd cars, impossible to find spare parts for them.

From 1997 onwards, we have been using the C20 stock, which uses IGBT control and asynchronous traction motors, completely electronic.

As a green line driver, I am of course of the religious conviction that camshafts are something that might perhaps be suitable for the red & blue line, and other, lesser, organisations. However, for real work, on a real line, it has to be pneumatic contactors or thyristor control all the way! ;D

I'm off to work now, but when I come home, I'll see if I can't scan a few pictures of one of our old contactor assemblies and post them.


/Igelkotten

[igelkotten]

I have no idea if there are any DVDs of the Stockholm tube available. I know that there are fragments about the tube interspersed with other things in some historical videos and so on, but as far as I know, there is no video or DVD solely about the Stockholm tube. Maybe Tom knows about one?

For a lot of pictures from Stockholm, including driver's eye views and photos from the depots, take a look at Tom's Fotopic site:

www.tunnelbana.fotopic.com


/Igelkotten

[Dmitri]

Q8 said:

Thanks for the website address Mr Igelkotten but I'm afraid it comes up "page can't be displayed" Even when you cut and paste the link.

A small error crept in - it is actually tunnelbana.fotopic.net/.

[Tom]

Igelkotten said:

I have no idea if there are any DVDs of the Stockholm tube available. I know that there are fragments about the tube interspersed with other things in some historical videos and so on, but as far as I know, there is no video or DVD solely about the Stockholm tube. Maybe Tom knows about one?

I can only draw a blank on this one too. I have seen videocaps from a video by Roffe Bergman, but haven't been able to find anything else out about it. Otherwise, 'Metros of the World' is your best bet, although it is now 17 years old and looking a bit dated.

BTW thanks Igelkotten and Dmitri for the promotion of my work, saves me having to do it. ;D