Positive Train Control and High Speed Rail

Jersey_Mike wrote:

However, if the speed had been lower than 15, with the engineer not paying attention, he could still have passed the home signal and collided with the freight train, which had practically reached the interlocking by that time.

You're right it is not as perfect as PTC, but the cost/value ratio is remarkably better. Look at the Northeast commuter operations. Millions of passengers carried every year and not a single fatality due to a passed stop signal in CSS territory. You have a greater chance of being killed by a crazed gunman on the LIRR than you do rolling past a stop signal. PTC is a solution in need of a problem. The irritating part isn't just the cost, its that the whole technology doesn't work very well. The mandate prevents the FRA from adopting flexible regulations that would allow PTC to supplement reliable signaling technologies, but still allow it to be cut out or ignored.

This is exactly what concerns me about PTC being mandated by a date certain. Is it really perfected and ready for prime time all by itself? Will it prevent a movement from running by a stop signal without unnecessarily taking control of the train out of the hands of the engineer before the train reaches the signal? Existing CSS would probably prevent the vast majority of possible collisions -- and it works. (It also knows which track each train is on.)

ExCon90 wrote:

Jersey_Mike wrote:

However, if the speed had been lower than 15, with the engineer not paying attention, he could still have passed the home signal and collided with the freight train, which had practically reached the interlocking by that time.

You're right it is not as perfect as PTC, but the cost/value ratio is remarkably better. Look at the Northeast commuter operations. Millions of passengers carried every year and not a single fatality due to a passed stop signal in CSS territory. You have a greater chance of being killed by a crazed gunman on the LIRR than you do rolling past a stop signal. PTC is a solution in need of a problem. The irritating part isn't just the cost, its that the whole technology doesn't work very well. The mandate prevents the FRA from adopting flexible regulations that would allow PTC to supplement reliable signaling technologies, but still allow it to be cut out or ignored.

This is exactly what concerns me about PTC being mandated by a date certain. Is it really perfected and ready for prime time all by itself? Will it prevent a movement from running by a stop signal without unnecessarily taking control of the train out of the hands of the engineer before the train reaches the signal? Existing CSS would probably prevent the vast majority of possible collisions -- and it works. (It also knows which track each train is on.)

ACSES does pretty much everything they want. It enforces permanent speed restrictions, it enforces temporary speed restrictions, it enforces positive stop signals and it enforces signal speeds. The only thing it does not do is physically stop a train from running into another train that is stopped ahead of it. BUT, since it enforces restricted speed at as little as 15mph. that alone is going to get rid of 98% of collisions. At 15 mph or less, it's pretty hard to not notice another train ahead and apply the brakes. And even if you did not stop in time, just throwing the train in emergency would get you down to a speed that would be at worst, a hard coupling. Likley not hard enough to seriously injure anyone or cause much damage.

If you really look at all the accidents the FRA and NTSB are trying to avoid with PTS, it's stop signal violations. Untill ACSES, nothing was available that could stop a train at a home signal. Cab Signals warn you of a stop signal ahead, but they will not stop you from going by it. ACSES will. ATS will apply the brakes after you go by the stop signal, by then, it's too late.

And i still have yet to see how PTS will deal with shoving movements. Like ACSES, there is no realistic way to stop a movement from passing a stop signal when the locomotive is not on the leading end.

I really don't see why the government is mandating such an outrageously complicated system. Good training and the right choice of Engineers combined with a system like ACSES is all you need. Just another case of the government trying to overcomplicate everything. What ever happened to just knowing how to do your job? Maybe the real issue is the railroad should start hiring people with a decent level of intelligence and not worry about filling quotas with the right "types" of people. Hire the best PEOPLE for the job and give them the proper training. It's scary that the quality of training is going down and the character of people being hired is as well. Not good.

If you really look at all the accidents the FRA and NTSB are trying to avoid with PTS, it's stop signal violations.

Unfortunately the PTC mandate also covers permanent and temporary speed restrictions and open switches. I'm surprised they didn't throw in protecting trains from kitchen sinks left in the right of way. Yes this is all very good, but they are letting the perfect become the enemy of the good. The technology can definitely help crews do their job, but it shouldn't be considered THE thing that is needed to keep train accidents from killing scores of people every year.

What ever happened to just knowing how to do your job? Maybe the real issue is the railroad should start hiring people with a decent level of intelligence and not worry about filling quotas with the right "types" of people. Hire the best PEOPLE for the job and give them the proper training. It's scary that the quality of training is going down and the character of people being hired is as well. Not good.

If you look at the FRA document you'll see that the accident rates are about 10% of what they were around 1980. Rail accidents that PTC can actually prevent are very rare events even without any form of supplementary protection. I am going to write my elected officials so that when things hit the fan they will know that not everyone wants them to think of the children and they should give the FRA some flexibility in preventing future rail accidents.

This reminds me of now the NTSB wants expensive ground radars to prevent runway incursions at airports, but the FAA has discovered that using runway holding lights (Taxiway signaling!) the incursion problem drops dramatically at a fraction of the cost.

Jersey_Mike wrote:BTW another thought I had was that in dark territory the new PTC stuff will automate movement authorities, but there will still be no train detection so if something happens on the back end server to "lose" the train one is going to have a problem. Nobody should trust commodity "software" for vital safety applications. Stick with relays, ROMs and ASIC's. Once you have SignalSoft 2.0 sending vital safety to trains in the field you know its going to be running on Windows and you know its going to get connected to the internet and that spells Trouble with a capitol T and that rhymes with P and that stands for PTC

Well, we can hope they'll run it off Linux-for-embedded-systems instead, and have no Internet connection (at most an outbound serial data dump).

I'm a computer security researcher and the best way for "industry" to try to keep SCADA systems secure is to force someone to actually drive out into the field and muck with it. If you make it accessible to the network then state or terrorist actors can sit back and completely pwn you from the safety of their home country. Centralized Computer based interlocking is all the rage in Europe. Hopefully they will be providing the world with a nice little object lesson on the ways that can go horribly wrong before someone tries to adopt it over here.

I know what you mean.

Well, we can hope they'll run it off Linux-for-embedded-systems instead, and have no Internet connection (at most an outbound serial data dump).

Amtrak's ITCS actually got the implementation about as close to the mark as one can. The PTC servers are all out in the field and don't require any sort of central coordination or external network connection. They are linked in a WAN that could use wireless links, but that can be set up properly and because the servers are some sort of embedded system with a serial out you won't have people trying to check their g-mail on them. Still, even with this simple system it's still in "testing" after 13 years and they just had to knock speeds back down to 80mph to carry out an "upgrade".

There's an odd silence coming from both the industry and transit agencies re: PTC as if this isn't going to be some huge massive problem. A few isolated test pilots on low density dark territory with fallback systems in place does not mean one is ready for a nationwide rollout on 100,000 miles of tracks in 6 years. Predominantly commuter routes can always buy the now proven ASES and ACSES systems, but that's still going to cost money that will be increasingly short in this age of budget cuts. I feel that they have some sort of regulatory or legislative ace in the hole and are just waiting for the right time to play it. Reminds me when California "required" something like 20% of the vehicles sold in the state to be zero emissions by like 2005 or something wherein the automakers rolled out a few test electric vehicles which sucked, threw up their hands and called the state's bluff, which prompted the regulations to be scaled back. For example nobody has mentioned what sort of sanctions railroads will face if they ignore or are unable to meet the mandate. If the cost of the sanction is substantially lower than implementing PTC the railroads will just treat it as a cost of doing business, especially if the FRA has latitude to set the punishment. It's like if a car company doesn't meet the CAFE standards. The government doesn't go out and seize the gas guzzlers, the company just pays a tax.