Amtrak Washington train crash: Deaths as carriages fall on US motorway - Page 2

kraznyi_oktjabr · 12-19-17, 08:15 PM

Quote:

Originally Posted by Platapus

My cheap Garman alerts me when the posted speed limit changes and alarms when I exceed that speed limit by about 2-3 mph. Is there any reason why such a device could not be used on a train?

Those systems work by determining where you are and then check what the map says about speed limit. In railways that works fine until next interlocking where there are different speed limits for main and secondary routes. That means in almost every interlocking you encounter, you have a problem.

For example lets say that main route has speed limit of 80 mph but when switches are turned into siding there is speed limit of 20 mph over switches (exceed that and you may derail). If your safety system relies on GPS and map then you must enforce lowest speed limit possible in that section of track. At first glance it may not look too bad but you must take into account braking distances and length of siding. Delays caused by unnecessarily low speed limit add up quickly.

Quote:

Originally Posted by Platapus

With practically everything on trains being controlled by computers, is there no way to program a governor to kick in when the speed of the train is almost three times the speed limit?

That is standard functionality of automatic train protection (ATP) systems provided that sufficient information about applicable speed limits is available (see above). Installation of ATP system into locomotive is relatively easy (emphasis on relatively) and is generally not restricted by technological level of locomotive. Ofcourse in modern locomotive you can integrate stuff directly into controls which avoids clutter (and hence human factors troubles) in locomotive cab design.

Here in Finland computerized ATP system has been installed into pre-WWII (museum) steam locomotives but fortunately it wasn't my headache to make it work!

vienna · 12-20-17, 06:53 PM

I owe an apology to propbeanie: Last night on a local LA news program, there was a discussion about the Washington train wreck and whether the same might happen here in SoCal. The question of PTC was brought up and, to the surprise of the interviewer (and myself), it was revealed local Amtrak rail lines do not have PTC in use on any of their routes. The surprise came about because the local commuter rail system, Metrolink, whiich uses Amtrak and other rail lines, does in fact have PTC and has had ever since the fallout from the Chatsworth Wreck. The predominant belief has been, since Metrolink uses PTC on Amtrak lines, Amtrak should have been using PTC, also. Amtrak, et al, have been taking advantage of the waivers and push backs given to them regarding installation of PTC and have basically ignored Metrolink's usage of the system. So, propbeanie, you are fully correct about Amtrak and PTC and I stand (well, actually, sit) corrected...

<O>

propbeanie · 12-20-17, 08:25 PM

No apology necessary, good sir.

The problem with information of that nature, beside its being proprietary, is the media 'reporters' who don't know the differrence between 'investigate' and 'repeat verbatem', nor do they recognize the difference between 'truth' and 'sensationalism'. Most folks don't know what a drawbar is or does on the railroad, much less what PTC is, nor where or why or how it's used. Even the big Class 1 roads had to ask for waivers, due to the sheer magnitude of the undertaking. All new equipment purchased, or rail lines upgraded, have had PTC as part of them for the last several years. It's mandated. Every little device has to have a radio link for communication with the system. I mean, even a burnt-out lightbulb at a public crossing at grade is tracked, and restricts trains. The complexity of the system is immense. The cost is immense. All of the privately held railroads, big & small, have been working toward compliance with the beast of a system. The entity that is lagging (that I know of)? Federally funded Amtrak. Why? Probably budget... They are trying to do a lot with the budget they have, but still... Railroading is not a low-cost, high profit industry.

12-20-17, 06:53 PM	#17
vienna Navy Seal Join Date: Jun 2005 Location: Anywhere but the here & now... Posts: 7,711 Downloads: 85 Uploads: 0	I owe an apology to propbeanie: Last night on a local LA news program, there was a discussion about the Washington train wreck and whether the same might happen here in SoCal. The question of PTC was brought up and, to the surprise of the interviewer (and myself), it was revealed local Amtrak rail lines do not have PTC in use on any of their routes. The surprise came about because the local commuter rail system, Metrolink, whiich uses Amtrak and other rail lines, does in fact have PTC and has had ever since the fallout from the Chatsworth Wreck. The predominant belief has been, since Metrolink uses PTC on Amtrak lines, Amtrak should have been using PTC, also. Amtrak, et al, have been taking advantage of the waivers and push backs given to them regarding installation of PTC and have basically ignored Metrolink's usage of the system. So, propbeanie, you are fully correct about Amtrak and PTC and I stand (well, actually, sit) corrected... <O> __________________ __________________________________________________ __

12-20-17, 08:25 PM	#18
propbeanie CTD - it's not just a job Join Date: May 2016 Location: One hour from Music City USA! Posts: 10,098 Downloads: 451 Uploads: 2	No apology necessary, good sir. The problem with information of that nature, beside its being proprietary, is the media 'reporters' who don't know the differrence between 'investigate' and 'repeat verbatem', nor do they recognize the difference between 'truth' and 'sensationalism'. Most folks don't know what a drawbar is or does on the railroad, much less what PTC is, nor where or why or how it's used. Even the big Class 1 roads had to ask for waivers, due to the sheer magnitude of the undertaking. All new equipment purchased, or rail lines upgraded, have had PTC as part of them for the last several years. It's mandated. Every little device has to have a radio link for communication with the system. I mean, even a burnt-out lightbulb at a public crossing at grade is tracked, and restricts trains. The complexity of the system is immense. The cost is immense. All of the privately held railroads, big & small, have been working toward compliance with the beast of a system. The entity that is lagging (that I know of)? Federally funded Amtrak. Why? Probably budget... They are trying to do a lot with the budget they have, but still... Railroading is not a low-cost, high profit industry. __________________ "...and bollocks to the naysayers" - Jimbuna