Tube underground track

mickoo

Western Thunderer
Loved the sound those doors made, not your Star Trek fssshh-ock, more a yuurrarrraauu.

Add to that the good old compressor thudding away under the floor, some coaches had a pressure gauge inset into the steel panel below the seats.
 
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oldravendale

Western Thunderer
Memory time again..... I remember father and I ensuring we were in the guard's car of 1938 stock (our normal route into town on the Bakerloo Line) so we could watch the guard and the dials. The guard was separated from the hoi poloi by a simple bar across the rear of the carriage.

Who else remembers guards on EMU's?

Actually I do - I should have said tube trains.

Brian
 

Tim Watson

Western Thunderer
Thread hijack is more than welcome: if we can achieve a fraction of that atmosphere, Pete, I’ll be well pleased. I have been sent the 1909 signalling diagram for the section of line, from a contact of Doug Rose.

We knew of the crossover, and it is apparently signalled for terminating a south bound train, which could then head north: that could be very useful as it avoids the need for a fiddle yard at the left hand end of the layout. The alternate route was also signalled, although that would be of no use to us. Anyone got any information on tube signals?

Tim
 
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Yorkshire Dave

Western Thunderer
Who else remembers guards on EMU's?

Actually I do - I should have said tube trains.

I remember guards on surface and tube stock - especially on tube stock with their head out of the open door as the train was departing. I think the Northern Line was the last line to remove the guards.
 

cbrailways

Western Thunderer
Hi Tim. Tube Line signals. Well again it depends on which period you are modelling. Here is one example of an early air worked one. In this example an air cylinder pushed a mechanical balance weight which was attached to the specticale plate. This moved upwards to move the green lens over the light and fell back to display the red light. It was therefore 'Fail Safe' in that any loss of air or broken component resulted in a danger (stop) aspect. The 'S' plate idenifies that this was an Automatic Signal No.262. You can also see a Trainstop mounted to the right of the righthand running rail.

tunnel-signal-and-automatic-train-stop-london-underground-railways-1926-artist-unknown-MPT819.jpg


This is a more 'modern' type which didn't have any moving parts:

Signals_and_headway_clock%2C_Charing_Cross%2C_London_Underground_%28CJ_Allen%2C_Steel_Highway%2C_1928%29.jpg
 
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Tim Watson

Western Thunderer
Many thanks. I think some very small LEDs and gubbinery will do the trick, although that would be a long way down the line...

Tim
 
A

Arun

Guest
Anyone know what the typical inter-tube distance was underground?

Thanks
Tim
If you mean distance between 12ft diameter tunnel centres, then you only need to go down to the Bakerloo platforms at Piccadilly Circus where the wall thickness at the level of the horizontal diameter is about five feet. It's one of the few places where you can stand on the end of one platform and see the other. Once the platform end is reached, the running lines diverge a bit of course.
A more extreme case is on the southbound Northern line where there are still a couple of island platforms - there the space between tunnels is only the width of the platform - again once past the tunnel mouth, the tunnels begin to converge to about five foot again. .
There are a couple of places on the Victoria line between Highbury & Islington and Finsbury Park where again you pass by an opening allowing you to see the opposite running line. Again, I would say the inter-tunnel wall is about five foot thick there.

There is at least one deep tube station which never had a suicide pit and that is Aldwych. I don't remember whether the associated branch platform at Holborn had a pit.
 
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cbrailways

Western Thunderer
...and to add to that. In the book 'Londons Underground' Third Edition published in 1962 it quotes:
The present standard internal bore of London's Tube tunnels is 12ft on straight track. Where stations are to be sited, the running tunnels, which are normally seperated by 5ft of soil, usually fork out to flank the platforms. Station tunnels are generally 21ft 2 1/2 ins. in diameter.......
 

Yorkshire Dave

Western Thunderer
If you mean distance between 12ft diameter tunnel centres, then you only need to go down to the Bakerloo platforms at Piccadilly Circus where the wall thickness at the level of the horizontal diameter is about five feet. It's one of the few places where you can stand on the end of one platform and see the other.

One of my photos. Piccadilly Circus Bakerloo Line platforms. Which was one of the Yerkes tubes along with the GNB&P (Piccadilly Line) and the Hampstead Tube.

00 Harrow 9.jpg
 

Tim Watson

Western Thunderer
Well it doesn’t get much better than that does it? Well actually, we now have the prototype track plan for the crossover at the north end of York Road, including all the tunnel bores. When it’s cleaned up and stitched together, I’ll post an image.
Thanks everyone!
Tim
 

Dan Randall

Western Thunderer
This is all pretty fascinating stuff, but what I don’t understand, is how those cast iron tunnel segments (which I presume have parallel sides?), are able to cater for any curvature in the track?....
970C4D52-95B8-4FE6-9562-E405DE1A9F9B.jpeg


Regards

Dan
 

cbrailways

Western Thunderer
Yes, facinating stuff, including how the tunnels were constructed and aligned with two plumb lines and a theodolite, and met up within a fraction of an inch. True engineering without a computer or calculator in sight......
 

mickoo

Western Thunderer
My understanding is that they were not all the same, some sections were wider for the outside of the curve, especially the sharper curves. Those top and bottom sections were tapered to suit. Bit like set track.

More gradual curves used standard sections with spacers between them, any small gaps were filled with caulking, but, as Peter noted, most deep bore tubes followed the blue clay seam under London so water ingress is minimal.

There are some fierce curves around Bank and I've no idea why given the depth of the line. One rumour is the li e diverts around the deep vault at the Bank of England. I recall there being several undulations in that area, I presume as the line tries to follow ripples in the blue clay.

Liverpool street out to Stratford is pretty flat and straight and probably one of the fastest sections on deep bore tubes, though there a great many fringe lines I've not ridden on.
 
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