Greetings and operational/technical questions

Posting about freight comparing it to passenger equipment has absolutly no comparison.
Push pull on average is done with about 7 cars which weigh only around 100 to 120 000 Lbs.
different couplers and a different brake system, including blended brake.

Push pull has proven safe with thousands of trains operated in USA per day alone, and many thousands a day in world.
Have there been derailments, yes, but not to many that would have had a different outcome if other equipment were used.
p/s As for SLE, been there done that, as for training engineers, so far 301 engineers behind me on roster came thru my cab and were instructed.

Saito S wrote:Well, I didn't expect to cause such a stir! Thanks for all of the info so far.

So from what I am gathering, aside from the somewhat disputed issues of safety, there really aren't any other disadvantages of cab car/push-mode operations that are worth mentioning.

As TO the safety issue... if I'm understanding correctly, the idea here is that there are emergency safety measures that would kick into place if a break in connections between the locomotive and the cars occurred (which is what is meant by "breaking the train line"). But in push mode, if it's the loco that derails, the engineer might not realize it until it's too late (and the train line would not be broken until after jackknifing has occurred). This is the potential problem scenario, and what essentially happened in New York in ThirdRail7's examples, yes?

Now, the argument about how true this is/how much of a concern it is... well, some of it is lost on me due to terminology, which I'll ask about now.
-What is "dump"? DutchRailnut refers to it as something the engineers or passengers could "do" during an emergency. ThirdRail7 mentioned one of the NY derailments ultimately caused the train "to dump".
-Plug? Would that be breaking the train line intentionally in order to trip emergency systems? That's what I got from the context in Desertdweller's post ("...you can plug a derailed commuter train in push mode, running at speed, before the compression force..."), but I'm not sure.

Dutch, I'm obviously no expert (hence this thread's existence), and you mentioned that you run trains yourself, but as far as what has been posted so far in this thread, I have to say that the opposing arguments make a bit more sense to me at this point. Especially given the examples ThirdRail7 mentioned. (Not discounting the possibility that I am simply not fully understanding everything here; certainly some of the terminology is unfamiliar to me, as I mentioned above). Also, in regards to the relative strength of a loco vs. a cab car: the weight difference, from what I can find (looked up weight figures for Kawasaki C3, Bombardier bi-levels, DE30/DM30 LIRR locos, and GE Genesis) seems to be 100,000 pounds or more (the cars all weighed in around 150k or less, the two locos weighed in at between 250k and 300k). That really doesn't make a difference when colliding with non-rail vehicles? Further, in the 2005 Glendale Metrolink crash I referenced before, the cab car derailed and jackknifed after hitting the SUV that had been left on the tracks. Is it really just as likely that the same fate would have befallen a locomotive?

I've also observed that LIRR seems to run dual locos, one at each end, with trains made up of DE30/DM30 locos and C3 cars... but only sometimes. I've seen vids of trains with a locomotive at each end, and vids of trains with only one, with a cab car at the other end. Anyone know what that's about? I had wondered about the feasibility of a transit agency or railroad having a "always lead with a loco" policy... obviously this would require either ALWAYS having a loco at both ends for every revenue trip, or a way to turn the loco around at a terminus (does ANYONE still use turntables? They seem to be mostly obsolete as far as I can tell. I wonder if this would be viable though?).

As for walking between the loco and passenger cars, it seems like this might be possible sometimes, with certain locomotives and cars, but certainly can't be counted on, and isn't in any way "standard" or necessary for proper operations. Thanks for the info on that, Desert.

Thanks again to everyone for any and all information. When I started building this project, I was aiming fairly low as far as the complexity of the commuter rail system, but its since grown quite a bit in scope, and I was simply no longer satisfied with my lack of knowledge in this area!

When you see a LIRR train with an engine on both ends, it is most likely headed to Penn Station or it has a lot of cars and needs the extra power. LIRR uses two for NYP do the engineer can always see the third rail, which prevents the train from gapping.

As for safety and accidents in push pull operation, no accident is identical. There are similarities, but no accident is exactly the same. You can't plan for everything. Let's take it another direction. What if the engine was operating lead during the Metrolink accident and the car wedged under the engine's fuel tank, which becomes dislodged and the fuel from the car ignites everything? Probable? No. Possible? Yes! That would be far more dangerous than a jackknifed train, no?

Desertdweller wrote:
I retired 85 weeks ago.

But, who is counting, right?

Dutch,

The same laws of physics apply to all trains. If the locomotive is at the rear, pushing against the cars, the train is in compression.
If the train is in compression, it is apt to jackknife if it derails. All the fancy braking systems your train has isn't going to prevent
that.

The understanding of compression, tension, and slack is really Locomotive Driving 101. Take that understanding away, and what you have left is a bus driver.

Your short, light train with the engine in the rear might resemble an elongated bus, and apparently it can be handled as if it were one. But if it puts a wheel on the ground, it is going to behave like the train it is.

I'm not trying to be snarky or demean your accomplishments. Maybe you've only worked in a highly maintained environment of protected right-of-ways and extra-heavy rail where derailments never happen. Maybe a 1,000 ton train is considered a big one.

Have you ever ran a train that went on the ground? Have you ever had to dump the air instinctively, without having the time to think about it first? Did you train your students to do so?

I've never ran a train 90mph. The fastest I've ever gone was 65, but with a freight train behind me. I've run on cab-signalled and CTC track, and TWC territory. I've run 12,000 ton trains on 72lb. rail. I've run 12hrs. on 10mph track.

I've also had to investigate derailments to try to determine a cause. Often track is totally destroyed and there isn't a lot to go on. Sometimes this results in finger-pointing between Engineering and Operating Departments, each eager to put the blame on the other's guy to avoid criticism.

I have not had your passenger train experience. You maybe have not had my freight experience, I suspect not. But the same laws of nature apply to both.

Judging from my own experience, the potential for extreme damage from a shoving derailment is greater than a pulling derailment. The advantage I have had in shoving moves is the engineer can watch the cars moving ahead of him and plug the air if he sees trouble. Riding the cab car in a pushing move, you do not have that advantage.

Did you use simulators as well as actual locomotives to train your students? One thing that I always did was to have a student suddenly plug a train at low speed. I always used small trains for that one, but I wanted for them to have the experience, so they would not be afraid to do that if necessary. I find a lot of students are hesitant to plug a train for fear of what would happen. Actually doing it overcomes their fear. A simulator would be a good way of doing that in your situation.

Thirdrail7:

Looks like I'm counting.

I enjoyed my career, but it resulted in a lot of time away from my family. A good part of the time I was away from home on projects, starting up small railroads or working as a contractor to established ones. My children mostly grew up without me.

My last assignment kept me on the road for 22 solid months. I was literally a "Desertdweller", living in a little trailer in the Chihuahuan Desert and buying two houses I did not get to live in. When I had enough credits to retire, I did.

I came home to my Nebraska house. I try to spend time with my grandchildren here, and with my wife of 39 years.

My railroading now takes place in my basement. My model railroad is based on passenger operations in Denver in the 1960's.
It is not push-pull. Every train has a proper first-generation Diesel locomotive on the head end, pulling the train as God intended.

Les

not gone argue, but even my model railroad runs two FL-9's pushing 7 Bombardier coaches and hardly derailing

Dutch:

Very good!

I only shove cars into station platform tracks, or into my reverse loop.

Denver Union Station was built as a run-through station, but in the era I model all arriving trains departed in the direction they came from. So they all have to be turned.

When I worked in Hartford, I was pleased to see the CDOT equipment painted and lettered in the New Haven colors. There seemed to be an ongoing love affair with the NH. It was too bad that the state could not have purchased it to keep it from falling into PC.

I think the attachment the people of CT have to the NH could be repeated (with UP permission, of course) on the Colorado Front Range, reviving the D&RGW paint on the future heavy-rail commuter system. When the Ski Train was in operation, it really looked great in the Rio Grande single-stripe scheme. Even the F40's looked good in those colors.

The Royal Gorge Railroad has adopted this paint scheme. Of course, it is a natural for F units.

The city of Denver really dropped the ball when it did not purchase the Ski Train from Anschutz. They already own the Winter Park Ski Resort. But now, after a heavy snow when ski conditions are optimal and the highway is impassible or nearly so, the skiers cannot access the ski area. Maybe the new heavy rail transit can correct this, but I suspect it would involve a hefty payment to UP.

There was at least one FL9 still in service at the time I worked in CT. I saw a lot of dead ones in the Naugatuck Valley.

Did you run any of the FA's that were converted to cab cars?

Les

only one, set on a LIRR Histirical society trip, and a F7 cab unit on a histyrical excursion.

Sorry to be away from my own thread for so long, things have been a little crazy!

I really appreciate all the info. ThirdRail, you did make a good point: it's not like having the loco at the front is some kind of 100% guarantee that nothing bad will happen, and the precise circumstances of every accident/derailment are going to be different. As for the LIRR trains, aside from a particular train having lots of cars (in which case, the reason for a second loco is obvious), I didn't know that about NYP. Gapping, in this context, is...? On that note, is there like a rail terminology glossary somewhere? XD

Desertdweller and Dutch, it's been interesting to hear both of you recount what you know from your experiences with actual work on trains (which is obviously something I have never done). Though just for the record, Desert, I actually did know what a cab car is already, and mentioned it in my first post, but to be fair to you, both posts I've made here have been serious text walls!

My takeaway right now is that overall, there probably ARE some safety risks that exist when operating in push mode, that are absent in pull mode. Of course, in theory, the reverse is also true, but the net result when they are all weighed is that push mode is the "more risky" one, if only very slightly so.

Bringing this back around to the issue of the fictional city/transit system building project I'm working on... in trying to determine how much - if at all - my created agencies would run commuter and inter-city trains in push mode with cab cars, I wondered how believable it was to say that they just don't, period. That instead, they either ALWAYS have two locos on every train, or have to switch the loco from one end to the other (and possibly turn it around if it's a model with only one cab end, which most of their locos probably would be, which would mean every terminus station needs a wye)... from what I'm gathering, the safety concerns of push mode are there, but the practical differences in risk to passengers on a push train vs. a pull train are relatively minor, even if they do exist.

So basically, I'm kind of torn. DOES it seem believable? Even though I envision this agency as quite well equipped and managed as transit agencies and commuter railroads go, how feasible is it really to say they simply never run in push mode? I'm starting to get the impression that it probably isn't that feasible, especially if they have a good safety record (meaning, the number of accidents that occurs in the first place is relatively low, thus whatever risks there are in a push mode accident are less of a deciding factor for how to operate).

Saito,

If the track structure can reliably handle trains running at speed in the push mode, I see no reason not to operate commuter trains in the push mode. While the possibility of a jackknife derailment exists in push mode, a heavy track structure reduces the chance of any derailment happening.

Big-city rail transit systems typically use heavy rail, and they are well inspected and maintained. Push-pull commuter operations are the industry standard in this country, so they must be cost-effective. They are not inherently unsafe.

Who knows what fictional directors of a hypothetical railroads would favor?

I do know that running all trains in pull mode would not require a weye at each terminal. You do not need a locomotive at each end of each train. All you need is a track you can run your power around your train on, and a double-ended locomotive.

Some electric locomotives are double-ended. Diesel locomotives can be operated with either hood leading, if they are hood-type units (like Geeps). Some are even constructed with two control positions in the cab to aid this. The ones with only one control location can be run reversed also, the engineer just has to look down the long hood. Since passenger operations typically require two crew members in the cab, the person riding on the "fireman's side" can help watch for grade crossings and signals. The crew is required to call out and acknowledge signal indications to each other anyway.

It is not typical to have an operating locomotive on each end of a commuter train.

Something else you might consider would be to use multiple-unit cars (electric mu's or RDC's). In this scenario, each car would be powered, controlled from the cab on each end of the consist. These could be run as individual cars during light traffic periods.

When I worked in Hartford, AMTRAK ran a short-haul intercity train between Springfield (MA) and New Haven. Maybe they still do. This train consisted of AMFLEET cars, with a P42 locomotive on the north end and a de-powered Metroliner car on the south end as a cab car. This train shuttled back and forth several times a day, sometimes with extra cars added. I rode this train once to Springfield.

Les

Saito S wrote:I've also observed that LIRR seems to run dual locos, one at each end, with trains made up of DE30/DM30 locos and C3 cars... but only sometimes. I've seen vids of trains with a locomotive at each end, and vids of trains with only one, with a cab car at the other end. Anyone know what that's about? I had wondered about the feasibility of a transit agency or railroad having a "always lead with a loco" policy... obviously this would require either ALWAYS having a loco at both ends for every revenue trip, or a way to turn the loco around at a terminus (does ANYONE still use turntables? They seem to be mostly obsolete as far as I can tell. I wonder if this would be viable though?).

as for the LIRR, they run 2 locomotives on either end when they are either running into New York Penn (so they have less chances of gaping, as Mr. ThirdRail said). They also use 2 engines when they run a train with 8 or more cars, as the DE/DM's can only handle 6 cars on their own.

But for the most part, trains run with 1 engine on the east (Montauk/Greenport) end (why east? I haven't a clue, I guess it makes it easier for swapping out locos of they are all facing the same way) and a cab car on the west (LIC/Jamaica) end.

As to the "Always a Lead Loco Policy" that would be most difficult for most railroads (at least in the NY region). Most engines nowadays only have a cab on one end (some have cabs on both ends—like the AEM's, HHP's or ALP-46's), but cabs on one end means the engine or train must be physically inverted after each run. Most places that would be impossible. There are very few loops, almost 0 timetables, and quite few wyes to make this happen. To get an always leading loco, you would have to position a locomotive at each end, practically doubling the costs.