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Severn Tunnel safety

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island

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Is it true that a HST with a power car missing or inoperative can't go into the Severn Tunnel in case it can't get back out?
 
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louis97

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Can't see anything in the sectional appendix prohibiting it, and I am fairly certain I've read before of HSTs operating Swansea-Paddington services with only one engine. As you won't ever need to actually stop within the tunnel, and you'll be going 75mph through it anyway can't see any reason a train won't get out if operating without any other faults. (Lights are present half way through the tunnel to advise when to apply power, freight trains use them).
 

Envoy

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I boarded a south Wales bound HST at Paddington. We were informed on departure that only one of the locomotives was working and that the train would be slower than normal. The acceleration was markedly slower than normal and it arrived in Cardiff 30 minutes late. So, yes, HST's with only one engine working can go through the Severn Tunnel.
 

455driver

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A HST on one engine must have a clear run through the tunnel before being allowed in, that's about it really.
 

Flamingo

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Is it true that a HST with a power car missing or inoperative can't go into the Severn Tunnel in case it can't get back out?

Never heard of it. The only restrictions I am aware of with the Severn Tunnel is that a passenger train and a freight with dangerous goods / a steam train can't be in it at the same time.

I've worked several HST's on one power car through the tunnel.
 
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Jonny

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A HST on one engine must have a clear run through the tunnel before being allowed in, that's about it really.

I thought it was a single block anyway. Given that, why would it make any difference?
 
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455driver

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There are signals in the tunnel, I don't go down there but I think its in 3 sections.
 

louis97

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There are signals in the tunnel, I don't go down there but I think its in 3 sections.

The only signals in the tunnel are repeaters for the signals at each end. The tunnel itself is just one section. Both lines through it are bi-directional also.

There are also red lights that are illuminated in the event of an emergency and if lit you are to stop.
 

455driver

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Thanks, serves me right for only looking quickly at it.
 
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Mugby

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I do believe though, that if all pumps failed at the same time, the tunnel would be flooded in less than five minutes!
 

Flamingo

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I do believe though, that if all pumps failed at the same time, the tunnel would be flooded in less than five min I utes!

The reason there are several, including back-up pumps.
 

edwin_m

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Never heard of it. The only restrictions I am aware of with the Severn Tunnel is that a passenger train and a freight with dangerous goods / a steam train can't be in it at the same time.

Does that mean a steam train can only go through if it is not carrying passengers?
 

Flamingo

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No, sorry, I wasn't clear. A steam train and a diesel passenger train usually won't be allowed in together. I'm not sure about a steam and freight at the same time, but I doubt it.
 

PeterY

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The only signals in the tunnel are repeaters for the signals at each end. The tunnel itself is just one section. Both lines through it are bi-directional also.

There are also red lights that are illuminated in the event of an emergency and if lit you are to stop.

Are the repeaters the standard type Banner Repeaters used elsewhere on the network?
 

louis97

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Are the repeaters the standard type Banner Repeaters used elsewhere on the network?

No, they are actual repeater signals, the signals before entry are 2 aspect therefore a green/yellow repeater signal are required. A banner repeater is generally used for when a signal is not visible till you are at it, although they can also be used to extend the length of time you know the next signals aspect. An example of the latter is on the Midland Mainline in relation to the line speed increases and also between Bath Spa and Bristol in the Keynsham area where a new signal was added - requiring more notice of signal aspects to allow adequate braking distance.
 

gwr4090

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Never heard of it. The only restrictions I am aware of with the Severn Tunnel is that a passenger train and a freight with dangerous goods / a steam train can't be in it at the same time.

I've worked several HST's on one power car through the tunnel.

The Sectional Appendix doesn't mention anything about restrictions involving steam trains, just freight trains carrying dangerous goods.
 

Taunton

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I believe the gradients down to the bottom of the tunnel are not that steep, only 1 in 90/100, so not really an issue if only on one power car. The river is not actually that deep at this point.

I'm surprised that it's now a single block section through there, as intermediate colour light signals were installed in there back in GWR days; must have been removed at some time. The rails in there only lasting a few years was also a feature of the tunnel back in steam loco days.

I always felt it unfortunate that when the second, most recent, road bridge was built, which closely parallels the rail tunnel, that advantage was not taken to build a combined rail/road bridge, and finish with this maintenance and operational liability.
 

Flamingo

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The Sectional Appendix doesn't mention anything about restrictions involving steam trains, just freight trains carrying dangerous goods.

The steam train thing is something I was told, as the fumes cause everyone on the diesel train to panic as they think the train is on fire. I've been in a train that went through behind a chuff-chuff and it was "interesting"!
 

Johnnie2Sheds

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Interesting. I do remember as a teenager being on a train hauled by D1059 Western Empire (XX:XX Paddington Cardiff) in about 1975, rolling into the tunnel and being brought to a near stand at what I assumed to be the bottom of the tunnel. I could clearly see ladders down to what I thought would be the sump or pumps. We were doing walking pace when the signal cleared. I can still hear it. :)
 

D1009

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The steam train thing is something I was told, as the fumes cause everyone on the diesel train to panic as they think the train is on fire. I've been in a train that went through behind a chuff-chuff and it was "interesting"!
Isn't that the case with any tunnel, though?
 

Taunton

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The steam train thing is something I was told, as the fumes cause everyone on the diesel train to panic as they think the train is on fire.
Extraordinary. I can (just) recall going through in steam days. A lot of coal, including all that Welsh steam coal for the rest of the Western Region loco depots, came through the tunnel, double-headed, commonly by a 2-8-0 assisted by one of the 2-6-2T tanks specially kept at Severn Tunnel Junction for the purpose. There would be a continuous parade of these in between quite frequent passenger services. Despite all the fans the tunnel atmosphere never cleared because of the intense service, all the regular passengers knew it and would slam the sliding ventilators shut as you entered. There was a most distinctive smell about the place.

Having said that, there were much worse tunnels on the system. The Severn is at least double track, with air space alongside. Being on a double-header on the S&D going out of Bath through Combe Down tunnel, single track, 1 in 50 up, no ventilation, and very tight with the chimney blasting at the tunnel roof just inches above, was way worse back in the train, what it was like on the second loco doesn't bear thinking about. If you got a slip you might not be certain which way the train was going (the crew would put a stick out against the tunnel wall to test).
 

Carlisle

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I'm surprised that it's now a single block section through there, as intermediate colour light signals were installed in there back in GWR days; must have been removed at some time.

Maybe these changes you describe to the signalling block sections were made in the aftermath of the 1991 Severn tunnel accident
 
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edwin_m

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Being on a double-header on the S&D going out of Bath through Combe Down tunnel, single track, 1 in 50 up, no ventilation, and very tight with the chimney blasting at the tunnel roof just inches above, was way worse back in the train, what it was like on the second loco doesn't bear thinking about. If you got a slip you might not be certain which way the train was going (the crew would put a stick out against the tunnel wall to test).

Combe Down tunnel was fatal on at least one occasion, even without the "benefit" of double heading.

http://www.railwaysarchive.co.uk/docsummary.php?docID=1999
--- old post above --- --- new post below ---
I always felt it unfortunate that when the second, most recent, road bridge was built, which closely parallels the rail tunnel, that advantage was not taken to build a combined rail/road bridge, and finish with this maintenance and operational liability.

When a Severn barrage was being talked about, it was proposed to run a railway across it.
 

Railsigns

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I'm surprised that it's now a single block section through there, as intermediate colour light signals were installed in there back in GWR days; must have been removed at some time.

The GWR installed intermediate block signals inside the tunnel in 1941 and removed them in 1947.
 

Flamingo

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I always felt it unfortunate that when the second, most recent, road bridge was built, which closely parallels the rail tunnel, that advantage was not taken to build a combined rail/road bridge, and finish with this maintenance and operational liability.
it was probably going to be slower than the tunnel, by the time the train driver stopped at the toll booth, got out his money, got his change and receipt, waited for the barrier to raise and pulled off again there was no speed advantage... :lol:
 

PeterY

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it was probably going to be slower than the tunnel, by the time the train driver stopped at the toll booth, got out his money, got his change and receipt, waited for the barrier to raise and pulled off again there was no speed advantage... :lol:

LOL. Only want to cross the bridge not buy it. :D
 
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