I was actually told by a rep working on such systems that PTC will result in SLOWER speeds. Why? Currently when a train traverses a speed restriction, let's say a 45 mph curve, the hogger makes the necessary adjustments in throttle, air brake, dynamics to achieve that speed. The hogger may start into the restriction at 47 mph but he knows his train and railroad well enough so as to be safe. PTC removes the hogger's judgement. Now the hogger has to be at or below 45 mph prior to entering the restriction so as not to incur a penalty. Such is progress.
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Higher operating speeds also mean longer stopping distances for the trains operating at the higher speeds, which in turn requires re-spacing signals or generating additional signal indications to provide safe braking distance within the signal systems abilities. Even trains that are not operating at the higher speeds are bound by the indications and/or spacing of the signals, which in some circumstances will slow down the operation of the line.
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BroadwayLion (12-23):
Ah, yes, changing gear ratios is cheap compared to the railroad as a whole. UP has changed gear ratios in the past, but did so very seldom.
Changing gear ratios is a tradeoff. Any higher speed is obtainable through gear ratio alterations, but the pulling power goes down at the same time. That’s why motor vehicles have a first gear, second, third, and so on.
Best,
K.P.
----------------------------------------------------------------------------------------------------------------------------------- K.P.’s absolute “theorem” from early, early childhood that he has seen over and over and over again: Those that CAUSE a problem in the first place will act the most violently if questioned or exposed.
Nah, the engines are a moot point. They can re gear them, they can send them to different districts, and they can buy new locomotives.
Locomotives *are* cheap compared to the rest of the railroad and its time+money issues.
Still, these are FREIGHT railroads and most do not ship time-sensitive commodities: They are flat out not interested in the issues involved with higher speeds than what they are now using.
ROAR
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While the original question is a most interesting one, in some ways it is irrelevant to the real world.
The overriding factor is a locomotive’s gear ratio, which typically is 70 M.P.H. rated for freights. With that gear ratio, I don’t think a train crew could get a train to 80 M.P.H. if it wanted to. There is a magical point where an engine will not accelerate further. An exception is in downhill situations … and nobody wants to court a 100+ M.P.H. downhill runaway.
Working in traffic and customer service, I use LTL services. What counts is consistency of service. It is 3 days to a point, I count on it.
Gaining 10- 20 miles of speed is not that big of a deal. If PTC means rail can increase its consistency of service, that does matter.
Deggesty Balt, I think I know what two roads you mentioned, and I expect that Ed is glad he did not work for the one that was taken over. Before all the hooraw and shouting were over, I was wondering why the new COO had not learned from a recent experience of his company: when you assume the operation of another carrier, you learn why it operated the way it did, and do not come in and immediately say, "We're making these changes because they work for us."
Balt, I think I know what two roads you mentioned, and I expect that Ed is glad he did not work for the one that was taken over. Before all the hooraw and shouting were over, I was wondering why the new COO had not learned from a recent experience of his company: when you assume the operation of another carrier, you learn why it operated the way it did, and do not come in and immediately say, "We're making these changes because they work for us."
It wasn't the one that was taken over that had the problems, but the new COO came from the one that was taken over. I might add, in the ensuing years approx. 90% of the taken over roads officials that were placed in positions of responsibility in the survivor company did not measure up to what the company expected of them and were let go.
Johnny
edblysard Faster trains isn’t the goal of PTC, closer/denser running and accident avoidance is. The problem with faster trains, beside the signal and ROW issues mentioned is simply this. You have to have somewhere to park the train once it arrives where it’s going, and if the yards or terminals can’t keep pace, then faster trains will end up parked on the main or in siding, which negates any gains made by running faster. Terminals and yards all “flow” or cycle at different rates, depending on the type of yard, type of traffic and location. These cycles are developed over a period of time, in response to the inbound flow of traffic, customers served, and type of traffic, they work themselves out in somewhat of a “balance” and any major shift in traffic will plug the yard, increase car dwell and generally cause all kinds of problems, from crew availability to locomotive availability. Just ask any UP manager what happens when you plug up a major yard!
Faster trains isn’t the goal of PTC, closer/denser running and accident avoidance is.
The problem with faster trains, beside the signal and ROW issues mentioned is simply this.
You have to have somewhere to park the train once it arrives where it’s going, and if the yards or terminals can’t keep pace, then faster trains will end up parked on the main or in siding, which negates any gains made by running faster.
Terminals and yards all “flow” or cycle at different rates, depending on the type of yard, type of traffic and location.
These cycles are developed over a period of time, in response to the inbound flow of traffic, customers served, and type of traffic, they work themselves out in somewhat of a “balance” and any major shift in traffic will plug the yard, increase car dwell and generally cause all kinds of problems, from crew availability to locomotive availability.
Just ask any UP manager what happens when you plug up a major yard!
Ed has nailed it - Railroads live and die by the efficiency of their terminals and their ability to turn traffic over.
Running trains at 100 MPH does nothing if a terminal can't stay fluid. Most Class I operating plans are predicated upon once a day service between signifigant Origin-Destination pairs which are based upon the volumes of traffic that move between those pairs.
A number of years ago, a senior manager from one company became the COO of another company in the same operating area. He implemented the operating philosophy of his prior carrier. Inside of one month, the carrier was at virtual gridlock with it's operations. The new 'plan' was predicated on 'fewer bigger trains' - which on it's face sound like a good plan for increasing the bottom line. The reality was that to facilitate these 'bigger trains' terminals had to accumulate cars to form those bigger trains - to accumulate the cars, those cars remained in the terminals longer (using track space all the while). Since cars for yet to be run Outbound trains were occupying track space in the terminals, they were unable to yard the 'bigger inbound trains' that had been dispatched from other terminals. Holding out those bigger trains (with power attached) meant that the power necessary for Outbound trains was stuck on the Inbound trains that could not be yarded because there was no available yard tracks. The 'plan' did not take into account the physical realities of the terminals upon which it was being implemented. The prior carrier had large hump yards with Receiving Track, Departure Tracks and many Classification Tracks. The new carrier had 'rationalized' it's terminals to encompass the level of traffic they were actually handling. The 'plan' did no acknowledge that the terminals were near their practical capacity and anything that disrupted the flow would overtax the capacity of the terminals. Gridlock.
If Terminals are not fluid - neither is the railroad that operates them, no matter what speed the railroad's trains operate.
23 17 46 11
ejjski I know this hasn't been talked about that much, but when PTC is finally implemented, would passenger trains be allowed to run at 90 mph and would certain lighter freight trains such as intermodal be allowed to run at 80 mph in certain places?
I know this hasn't been talked about that much, but when PTC is finally implemented, would passenger trains be allowed to run at 90 mph and would certain lighter freight trains such as intermodal be allowed to run at 80 mph in certain places?
First - Irrespective of the signal system, the condition of the track itself has to be adequate to permit these speeds. Under current FRA rules, FRA Class 5 track is requred for 90/80 mph operating speeds, while Class 4 track is required for 80/60 mph operating speeds (49 CFR 213.9). Installing PTC will not permit a line with Class 4 track to be run at Class 5 speeds.
Second - Even if track meets Class 5 standards, the track owner is not required to allow the maximum speeds allowed by ths classification. in other words, the FRA rule is merely permissive.
That said, there is a relationship between maximum permissible operating speeds and the type of signal system in place. FRA signal rules (and ICC signal rules before that) have long had restrictions limiting maximum train speeds based on the type of signal system. The restrictions are at 49 CFR 236.0. Until recently, FRA rules required that track over which trains (passenger or freight) were permitted to operate at 80+ mph had to be equipped with an automatic cab signal (ACS), automatic train stop (ATS) or automatic train control (ATC) system (this is the reason that train speeds on track equipped only with ABS was normally no faster than 79 mph). The PTC related signal rule amendments changed this in two ways:
First - Prior to December 31, 2015, track equipped with PTC can be operated at 80+ mph. The track no longer needs to be equipped with ACS, ATS or ATC to permit these speeds.
Second - On and after December 31, 2015, track at which trains are permitted to operate at 80+ mph must be equipped with PTC, unless FRA affirmatively permits the track to continue operating with ACS, ATS or ATC.
See FRA signal rules, 49 CFR 236.0(d)(1) and (2) for further information
The bottom line is that, if a segment of track cannot now be operated at 80+ mph because of the absence of ACS, ATS or ATC, installing PTC will permit these higher speeds, so long as track itself meets FRA track standards for the higher speeds.
oltmannd That's an interesting question. If your max freight train speed (including intermodal trains) is 60 mph (NS and CSX), you need class 4 track. Class 4 track is good for 80 mph passenger, so putting PTC on class 4 track would get you from 79 mph to 80. If you max freight speed is 70 mph (BNSF and UP), then it's class 5 track and the max passenger speed allowed would be 90 mph. However.... there are other hurdles to clear. If PTC is an overlay, are the block lengths and stopping distance going to allow the extra speed? Are there curves/superelevation restrictions? Do the grade crossing circuits/timing need adjustment? Are there line capacity issues from the increased speed differentials? "...Maintaining track to a higher track class is expensive work. You won't find much interest in the freight world as faster trains = more fuel, a lot more fuel and the intermodal equipment just isn't up to the task of running much faster than 70 mph..." So, there may be some spots where you'll find host roads allowing 90 mph - maybe for some extra $$, but by and large, PTC by itself won't get you much extra speed.
That's an interesting question.
If your max freight train speed (including intermodal trains) is 60 mph (NS and CSX), you need class 4 track. Class 4 track is good for 80 mph passenger, so putting PTC on class 4 track would get you from 79 mph to 80.
If you max freight speed is 70 mph (BNSF and UP), then it's class 5 track and the max passenger speed allowed would be 90 mph.
However.... there are other hurdles to clear. If PTC is an overlay, are the block lengths and stopping distance going to allow the extra speed? Are there curves/superelevation restrictions? Do the grade crossing circuits/timing need adjustment? Are there line capacity issues from the increased speed differentials?
"...Maintaining track to a higher track class is expensive work. You won't find much interest in the freight world as faster trains = more fuel, a lot more fuel and the intermodal equipment just isn't up to the task of running much faster than 70 mph..."
So, there may be some spots where you'll find host roads allowing 90 mph - maybe for some extra $$, but by and large, PTC by itself won't get you much extra speed.
Just a thought: I think that oltmannd (Don is pretty much spot on....Speed issues in the Freight Railroading world, (as long as the Passenger Operations are tennants) on the freight railroads are going to boil down to who wants to pay for the faster speeds?
Out here in fly-over country the big deal is the rerouting of the SW Chief. Amtrak is not satisfied with the performance, and wants a change, but BNSF is satisfied with minimum efforts to get the Chiref across from Newton,Ks.
The total spoken about to upgrade the line is something on the order of $100 Million dollars. The routes are pretty limited to go South (or Southwest out of Newton. There is the former RI south to Wichita, which is now UPRR (OKT Sub) or from Wichita switch onto the BNSF Transcon Southwest through Wellington and on West. Needless to say the BNSF is not happy about this prospect, on its' major freight route hosting a couple of Passenger Trains. The decision making process on this is still not concluded and has been wallowing around for several years. The current State Government (Brownback) has pretty much stimied the KDOT which was working on the ' Northern Flyer' extension of the current Dal-FTW Amtrak(Heartland Flyer) to OKC and North into Kansas. THere does not seem to be any updating of news on what will happen to the Chief and its present route or even what,where, and when a reroute (IF) will take place.
By itself? -NO
BroadwayLionPTC does not give you better signaling.
As an overlay, that is true. And, that is what the RRs are generally planning on doing. If and when they decide to make PTC a stand-alone replacement, then you can start doing things like "moving blocks" which could increase capacity. The "if" and the "when" will probably turn out to be "probably" and "not for a couple decades". Decent, reliable, braking curves for the particular trains are needed, too, instead of "worst casing" every train.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
PTC does not give you better signaling. Only better signaling and more signals can do that.
All PTC will do is save the life of a sleepy train crew.
I'll settle for that!
Maintaining track to a higher track class is expensive work. You won't find much interest in the freight world as faster trains = more fuel, a lot more fuel and the intermodal equipment just isn't up to the task of running much faster than 70 mph.
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