Glasgow District Subway.

[Trev]

I've started this thread here because I didn't want to get the quiz thread off topic.

I'm interested in how this subway worked when it was operated by cable. Syd has explained a bit in the quiz thread already (for which I'm grateful), but I still have a few more questions.

If the trains were operated by a clutch thingy onto a continuously moving cable, wouldn't that have made the acceleration from stopping to going a bit on the jerky side? Y'know, from not moving to suddenly moving at the speed of the cable? And it must have taken somne skill on the part of the drivers to know when to disengage the clutch and let the trains coast to a halt at a station.

This fascinates me, to be quite honest, but I'm not mechanically minded at all, and I just cannot work out for myself how it might have worked. I have a photograph in a book published by the NRM of the drum which powered the cable, and I have a vague memory of reading (or seeing on a TV programme) that some of the cable equipment had been preserved.

[swisstrains]

Cable cars such as the San Francisco system use a vice-like grip device to connect with the moving cable. The tighter the grip is applied the less the slippage and the faster the car goes. The man (driver) who operates the lever applying this pressure is called a "gripman" Conventional brakes are also fitted to make the operation a bit more flexible.
I assume the Glasgow system used similar technology.
John

[Trev]

Thanks John.

How was the cable made to go around curves with the grip attached?

[swisstrains]

Trev,
There is quite a good website here http://www.cable-car-guy.com/html/cchow.html#top explaining the various aspects of cable car systems.
I think it's true to say that most cable car systems only had cables running in straight lines. When the car came to a corner it had to release its grip, freewheel around the corner and then regrip onto the next cable. Where this wasn't possible (e.g. going uphill) the cable normally went around the curve on pulleys. When the car with its grip clamped to the cable passed around the curve it tended to pull the cable away from each pulley in turn so they had to have rubbing strips that the side of the grip could contact with to avoid it getting too far out of line. Apparently it was subject to a very high rate of wear and tear and because of the high degree of friction the cars had to go round these curves with a fair bit of speed which could be quite hairy
John.

[Trev]

That site is great John, thanks!

Everything I'll ever need to know. I didn't realise that the Great Orme Tramway was cable worked.

[swisstrains]

Originally Posted by Trev

I didn't realise that the Great Orme Tramway was cable worked.

Yes, I had also forgotten about Great Orme Tramway and I only travelled on it last Summer
John.

[Trev]

My Mum and Dad went there a couple of years ago. I reminded my Mum to have a ride on the tramway, and they did. If I'd have known that it was cable worked I would have asked her to take some photos.

Again off topic, but my Mum is usually pretty good like that. They went on holiday to Moscow and Leningrad in the mid 1980's and I asked her to take some photo's of Russian trains for me. I did mention to her to aske the permission of the Intourist guide first (this was before the Wall came down). However, Mum being Mum didn't bother and simply took half a dozen snaps at Leningrad station. The guide saw her and went ballistic! Luckily, she believed my Mum's explanation and was allowed to keep the pics that she had taken, but was warned not to take anymore. I was pleased that they let her off, it would've cost a fortune to send a Mothers day card all the way to Siberia!