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Signals in Tunnels

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Signals in Tunnels
Posted by Colorado Ray on Sunday, December 19, 2021 1:25 PM

I stumbled across an interesting accident report from a September 15, 1939 wreck on the Southern Pacific's Coast Line at Hasson siding.  Hasson siding is the first siding west of Chatsworth and the east siding switch home signal is approximately 650' from the west tunnel portal of the +7,300' long Chatsworth tunnel.  The distant signal is about 2,000 feet east inside the tunnel.  

A westbound freight, #373, the Coast Mechandise West, was traveling at 40 mph entering the tunnel.  An eastbound passenger train #72, had just arrived on the mainline when #373 exited the tunnel.  A Train Order had given #72 superiority over #373 and establishing a meet at Hasson.  So #373 should have stopped east of the siding to align the switch for the siding.  #373 exited the tunnel at such a high speed (on a descending grade from the tunnel apex) that it couldn't stop in time to align the switch so it ran head on into #72 at a speed of around 15 to 25 mph.  Fortunately, while there were no fatalitie, there were more than twenty passengers injured.  

The engineer of #373 said he had seen the yellow distant signal in the tunnel, but the fireman said he couldn't see it.  The conductor said there was too much smoke for him to see it.  

This is the first time I've ever heard of a signal in a tunnel.  Does anyone else know of other examples?  Subways don't count!

 

Ray

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Posted by csxns on Sunday, December 19, 2021 1:35 PM

Railroads in Norway have signals in tunnels and the tunnels are long.

Russell

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Posted by 7j43k on Sunday, December 19, 2021 2:31 PM

A bit of on-line searching turned up this article on signals inside Hoosac Tunnel:

 

https://www.jonroma.net/media/signaling/railway-signaling/1929/B%26M%20Installs%20Either-Direction%20Signaling%20in%20Hoosac%20Tunnel.pdf

 

Ed

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Posted by tstage on Sunday, December 19, 2021 3:33 PM

Ray,

Clarification: Is your query restricted to the era/time frame of the accident you referenced, which would pretty much narrow it to steam locomotives and a few early diesel?  Or, is it a general query that would include modern travel?

I could see where there might be some issues with smoke from steam locomotives inside a tunnel; obscuring visibility of a signal.  A fatal rear-end collision inside a NYC&HR tunnel in 1902 lead the New York City fathers in banning steam in and out of city limits by 1908 and the eventual development and use of electric-powered locomotives for that purpose.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by 7j43k on Sunday, December 19, 2021 4:19 PM

It appears the Hoosac Tunnel was signaled from 1910 to at least 1946, when the electrification was removed.

If I were looking for other signaled tunnels, I'd be looking for longish ones, with electric or diesel operation, and high train frequency.  

 

Ed

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Posted by gmpullman on Sunday, December 19, 2021 8:15 PM

7j43k
If I were looking for other signaled tunnels, I'd be looking for longish ones, with electric or diesel operation, and high train frequency.

There's lots of them in the approaches to Pennsylvania Station and Grand Central to be sure.

http://rrsignalpix.com/custom_nycpenn_colorlights.php

Regards, Ed

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Posted by Colorado Ray on Sunday, December 19, 2021 8:53 PM

tstage

Ray,

Clarification: Is your query restricted to the era/time frame of the accident you referenced, which would pretty much narrow it to steam locomotives and a few early diesel?  Or, is it a general query that would include modern travel?

I was generally thinking of more mainline tunnels rather than terminal approaches to stations like Penn Central or Grand Central.

Era doesn't matter, but I'd agree that diesel or electric would make it easier to spot.  Other than SPs cab forwards, I'd think seeing the signal would be problematic for an engineer.  Particularly when you hear stories of engine crews crouching low with wet towels to breathe through on long tunnels.  I'll have to check the engine number on #373 to see if it was an AC class cab forward or a MT or G class engine.

Ray

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Posted by wjstix on Monday, December 20, 2021 9:24 AM

I'd think the problem with having a signal in a tunnel in the steam era wouldn't be so much seeing the signal as it would be that if the signal indicated 'stop', the crew would all have suffocated by the time it changed to 'proceed'.

Dead

Stix
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Posted by 7j43k on Monday, December 20, 2021 10:54 AM

The comments about cab-forward steam locomotives got me wondering:

 

There were signals in the snowsheds around Norden, on the SP.

 

https://www.jonroma.net/media/signaling/railway-signaling/1935/Electric%20Interlocking%20in%20Snow%20Sheds%20on%20the%20Southern%20Pacific.pdf

 

Tunnels are mentioned in the article, but I see no statement saying signals were in those.  Or not.  But the area was EXTENSIVELY signaled.

 

I also suspect, but don't know, that there are signals in the First Street Tunnel in Washington, DC.

 

Ed

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Posted by DrW on Monday, December 20, 2021 3:22 PM

Long tunnels with high train traffic need some kind of signalling system. At least in Europe they have signals. I recently watched a video of a cab ride through the old Gotthard Tunnel in Switzerland. Every minute or so there was a green signal above "our" track and a red signal above the track in the opposite direction. The new Gotthard Base Tunnel does no longer have any visible signals. Instead, they use driver's cab signalling where the information is sent by radio to the monitor in the driver's cab.

JW

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Posted by BigDaddy on Monday, December 20, 2021 6:03 PM

I get motion sickness watching those train mounted cameras so modeling a signal in a tunnel isn't going to happen if that's the way anyone will see it.

#grumpoldmanpost

Henry

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Posted by dehusman on Monday, December 20, 2021 7:44 PM

Colorado Ray
The engineer of #373 said he had seen the yellow distant signal in the tunnel, but the fireman said he couldn't see it.  The conductor said there was too much smoke for him to see it.  

If they were saying that not seeing the signal contributed to the cause of the collision, somebody's blowing smoke and its not the engine.  It doesn't matter if the smoke obscurred the signal or not.  If there was a train order for a meet at the siding, it was given to BOTH trains, so #373 knew it was meeting a train there and should have been prepared to stop and line itself into the siding.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by Colorado Ray on Monday, December 20, 2021 8:04 PM

dehusman

No, they weren't blaming the signa.  The engineer said he saw the yellow signal indicating that the home signal was red.  While the fireman and conductor said they didn't see the signal that didn't contribute to the accident.  The final cause of the accident was excessive speed on the descending grade through the tunnel.  The engineer misjudged how fast he was applying the brakes.

 
Colorado Ray
The engineer of #373 said he had seen the yellow distant signal in the tunnel, but the fireman said he couldn't see it.  The conductor said there was too much smoke for him to see it.  

 

If they were saying that not seeing the signal contributed to the cause of the collision, somebody's blowing smoke and its not the engine.  It doesn't matter if the smoke obscurred the signal or not.  If there was a train order for a meet at the siding, it was given to BOTH trains, so #373 knew it was meeting a train there and should have been prepared to stop and line itself into the siding.

 

No, they didn't blame the signal.  The engineer said he saw the yellow indication on the distant signal so he knew the home signal was red.  The ruling on the cause was excessive speed on the descending grade from the apex in the tunnel.  The engineer misjudged how fast he was going as he applied the brake due to the poor visibility in the tunnel.

 

Ray

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Posted by jeffhergert on Monday, December 20, 2021 8:14 PM

A pdf of the investigation.

https://rosap.ntl.bts.gov/view/dot/46490/dot_46490_DS1.pdf?

To view the employee time table in effect, go here.  KM_364e-20170626154106 (wx4.org)  If that doesn't work, the long way is to go here  Historical Railroad Maps & Timetables, Page 2: Tim Zukas Collection (wx4.org) Then scroll down to Los Angeles Division 1939-6-11 #175 and click on it for a pdf.  (The next ett #176, took effect in 1940.) 

Numbers 373 and 72 were scheduled to meet at Hasson, with #373 being superior by direction.  The engineer on #373 that day was off the extra board.  He had just been assigned back to that extra board and it was his first trip on that portion after working elsewhere for about 9 months or so.  He said he was familiar with the area.

Jeff 

PS. If you have time to kill, this is the website for the time tables. The Wx4 Dome O' Foam  Go to the card catalog The Wx4 Card Catalogue, including New Arrivals for many interesting things.

 

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Posted by ndbprr on Tuesday, December 21, 2021 7:48 AM

I would think that the chunnel would definitely have them.

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