sorry anorak question

[dexxas]

on the times i been to stratford train spotting .via. the tube on the central line.. About mile end the tube really feels like its moving really fast! can anyone tell me me why this is? how fast is it actualy going ... many thanks

[russe]

dexxas said:

About mile end the tube really feels like its moving really fast! can anyone tell me me why this is? how fast is it actualy going

You're right, Dexxas. Stratford - Mile End is one of the faster tube stretches, because it is comparatively straight, and a decent distance. Not sure what speeds are being attained there though, but I doubt it is much in excess of 40mph; in the confined (and therefore noisy) space of a tube tunnel, speeds often feel higher than they actually are.

Russ

[q8]

The 62's used to touch near on 50 at Old Ford fan shaft and if you had the flag up [not allowed] 55mph The fastest unit I remember was 1724. [Strange how different trains of the same stock perform differently isn't it?]

[clavman]

The maximum ATP speed in any tunnel section is 65kph - that includes Mile End/Stratford. Prior to ATP the fastest speed was around 55mph max on the 62's and about the same as the then governed down 92's. 100kph target speeds are as far as I know available east of Liverpools St, and when ATP was first introduced on the Hainault loop tunnel sections 100kph target speeds were displayed east of Gants Hill, but not achieved as the trains were not in high performance mode. I think the reason that tunnel speeds are not higher than 65kph is the wind speed on platforms, although I've heard of other reasons as well. There was an anomaly not so long ago when the TS was 65, but the MSS ( maximum safe speed) was much higher. The ATO safely drives to MSS and 80kph was achieved between Liverpool St and Bethnal Green on the east. A similar anomaly exists today between Ealing Broadway and West Acton on the Eastbound.

[Deleted]

65kph is about 40mph.
80kph is about 55mph.
100kph is about 62mph.

Yeah, it does seem a lot faster when you travel as a passenger... hold your ears passing the fan shaft at Old Ford...

[Deleted]

Do you get used to the noise (and pain?) as you experience the change in air pressure as you go past the fan shaft?

[Deleted]

sturdjos said:

Do you get used to the noise (and pain?) as you experience the change in air pressure as you go past the fan shaft?

I've become used to the pressure sensation on the ears. The trick is to either swig a mouthful of tea, eat/chew something or yawn your head off on approach! You may be able to see a white band flash by which is painted onto the tunnel rings on approach to the fan shaft. The pressure sensation is more noticable when another train is passing going the other way.

[Deleted]

The various Central Line ATO speed codes, and ATP speed limits (in kph) are here - www.davros.org/rail/signalling/articles/central.html

[q8]

sturdjos said:

Do you get used to the noise (and pain?) as you experience the change in air pressure as you go past the fan shaft?

Not half do yer!! It used to actually close some of the fanlight windows as you passed. You'd hear the 'whoosh' as you passed it and then 'clap,clap.clap' as the windows closed themselves.

Before they restricted the speed you had a very simuilar thing occur on the southbound between St John's Wood and Baker Street. Another thing that you got at the latter location and Highgate southbound was dust. You'd see like a thin mist as you ran in. This was the dust you had pushed before you coming down. I once had a guard holler to me over the phone at Baker Street 'do you want a bell or a foghorn'?

[Deleted]

sturdjos said:

Do you get used to the noise (and pain?) as you experience the change in air pressure as you go past the fan shaft?

I have never had a problem with it, I always look forward to it happening as it makes you sound as though you are thrashing it more than the line speed! ;D

[Tom]

q8 said:

sturdjos said:

Do you get used to the noise (and pain?) as you experience the change in air pressure as you go past the fan shaft?

Before they restricted the speed you had a very simuilar thing occur on the southbound between St John's Wood and Baker Street. Another thing that you got at the latter location and Highgate southbound was dust. You'd see like a thin mist as you ran in. This was the dust you had pushed before you coming down. I once had a guard holler to me over the phone at Baker Street 'do you want a bell or a foghorn'?

While some of it may have been tunnel dust, the majority was found to be dust from brake blocks. Tunnel dust needs a lot of air concentrated at it for it to move, such as from a compressed air spray. The piston effect of the train, while it shifts a bit, doesn't contribute as much as brake blocks did.

[Deleted]

sturdjos said:

Do you get used to the noise (and pain?) as you experience the change in air pressure as you go past the fan shaft?

If you're getting pain from this change in air pressure, then you need to see a doctor!

[Deleted]

stephenk said:

If you're getting pain from this change in air pressure, then you need to see a doctor!

Thats what I thought!

[q8]

tom said:

q8 said:

While some of it may have been tunnel dust, the majority was found to be dust from brake blocks. Tunnel dust needs a lot of air concentrated at it for it to move, such as from a compressed air spray. The piston effect of the train, while it shifts a bit, doesn't contribute as much as brake blocks did.

Oh believe me there was more that sufficient pressure to shift tunnel dust at the locations stated. I have been standing on Baker Street south waiting to pick up and seen hats, papers and you name it go whizzing off down the tunnel if a train was coming down at speed. It was litterally a wind tunnel. Not so now of course.

[Deleted]

q8 said:

Oh believe me there was more that sufficient pressure to shift tunnel dust at the locations stated. I have been standing on Baker Street south waiting to pick up and seen hats, papers and you name it go whizzing off down the tunnel if a train was coming down at speed. It was litterally a wind tunnel. Not so now of course.

Dust on some equipment and wires in tunnels suggest the dust has not moved in many decades.

[q8]

Is there no attempt to clean the tunnel dust any more? The Fluffies are gone and so it seems is the TC train. That dust is a serious health hazard to trainmen and passengers alike and also a fire risk. More of 'bean counters' disease I suppose.

[Tom]

I've never known it to be a fire risk, but I wouldn't like to get covered in it too much any more. It used to take the best part of a week to completely wash it off

Though I don't think that cost-cutting has had an effect - yes the TC train doesn't run these days but I think that was more about it needing overhauling and it had to go away for that. And while we no longer have fluffers there is still an army of track cleaning gangs, admittedly not doing quite the same work but still removing some of the rubbish.

[stanmorek]

Yes its more like a couple of blokes (and ladies) walking between stations picking up litter into plastic bags nowadays!

Isn't a lot of this dust made up from human hair? I used to get covered in it working down there and then stop for lunch. Since the nearest station could be a long walk and there wasn't any wash facilities we'd eat there and then!

The accepted rule is that as long as nothing is disturbed and work is restricted to mainly visual inspection then there's no need for extra precautions. Though I've had some experiences I wouldn't care to repeat.

The only time I know dust (more like soot) is removed from tunnel surfaces is for repointing to brickwork. The immediate area is sheeted up and jet washed with the stuff bagged and disposed.

[q8]

Another thing about this non-cleaning is that the accumulation encourages rats and other vermin. I beleive there are some quite large spiders and cockroaches to be seen on the system nowadays. 'Public safety' is anathema to the bean counters isn't it?