THE ONE-SPEED SCHEDULED RAILROAD

[daveklepper]

I wonder if the Union Pacific or BNSF or anyone had done an economic analysis of the operation of the main line(s) of the railroad as a single-speed scheduled railroad. The largest variable cost is labor as I understand it. I note that currently on many ralroads, high-priority trains are dispatched with a high horsepower to tonage ratio and coal and similar trains with a lower ratio. What | am proposing is that the ratio be constant. That all trains get as much the same treatment as possible. Assuming that the system interchange modern freight car is good for 70 miles per hour, then that is the speed that all trains would operate at, or nerly all. Those trains with special hight speed equipment, including Amtrak, would get the additional 9 mph allowance but only to make up time. And there might be a once a day or once a week junk train that handles local business (mostly captive!) and any cars not good for the speed the bulk of the equipment is good for, and it is scheduled at a time when it is sure to be out of the way of the fleet. The additional power on each train is made available by quicker turn around of the power. The additional fuel costs are made up by reduction in labor costs, better utilization of crews. Scheduling is still desirable so that yard access and handling can be on a scheduled basis, conflicting moves at junctions, etc. The schedual is not fixed. It changes with maintenance of way work so that opposing moves where one of two running tracks is out of service are avoided, etc. But all moves are always planned, not just left to chance and are repeated while a specific condition of the railroad exists. At places where there are heavy grades, the same policy is used for all trains, helpers to maintain a specific speed, with the number of helpers dependent on the train weight. The railroad would recognize that some time sensitive shipments are simply more suitable for air or truck and there would simply not be any öne "big train." Unless the shiper were willing to pay an astromonical price, or course. It would that a car of chemicals or auto parts that shows up late but is important to the shipper could be tacked on the rear of whatever intermodal train was shortly to leave and would not be delayed at either end. It would mean the crews would know their hours of duty and the time that could be spent at home. I think this may be the philocophy that NS uses from Roanoke to Norfolk, and that may explain why they ran coal behind 2-6-6-4's at 70 mph.

I wonder what the real professionals think of this concept and whether it might be worth a real analysis. Dave

[dehusman]

Your premise balances the speed to the high side. Unfortunately you have to balance the speed to the low side to do what you want. Some freight cars are unstable over 40 mph, some over 50 mph and some over 60 mph. So if you want to be safe you have to operate the trains at the lowest speed, which means you would be running about 40 mph, not 70.
The problem is that if you operate everything to the low side, you miss the premium speed business because you take too long. If you balance things to the high side (assuming there were no issues with the stability of the cars) then you burn incredible amounts of fuel to do it. and you don't adequately get compensated for the extra expense. A utility isn't going to pay extra to move coal at 70 mph when they can get teh same thing at 50 mph. The only way bulk commodities benefit from speed in in the rapid turning of the equipment.
The vast majority of speed restrictions are in the track structure (curves, grades, bridges, switches, crossovers, etc plus defects which may cause slow orders). Unless the railroad builds a completely new right of way, they won't avoid those.

As far as scheduling the movements of trains, that works as long as you have a sophisticated enough scheduling system to handle several thoisand cars coming in from literally a dozen different directions and going to a dozen directions from each "yard" point. Then you have to keep all the myriad of things that delay an operation (weather, outside incidents, equipment failures, etc.) in mind schedule around those.

It is not as easy as it sounds.

Dave H.

[Junctionfan]

I would think a double track railroad with long and frequent passing sidings on both tracks would be better. Make all the slow ones go into the passing sidings and keep the hot-shots on the line. Make the lines like a road and run directional traffic-one direction takes one track and the opposite direction takes the other track.

It might be advisable to look at the possibility of using a heavier and more versatile version of those long european switches that can have high-speed traffic switch over on it. That eliminates speed reduction for crossing over. From what I understand, the current European ones are too light for North American freight traffic so some redesigning would be in order (of course research and implementation are equally expensive-the line would have to be busy enough to justify incorporating thease switches on that line)

I have a question with in my suggestions; before I suggest it, I would like to find out that is it true that the heavier the rail is, the harder it is for it to be worn? Because if that is the case, than I would suggest that the railroads could use heavier rail not so much to run the heavier loads but to add more life expectancy to the line before the need for replacement. Not knowing cost of the heavier rail versus the lighter stuff and also life expectancy of either, I couldn't make an accurate prediction.

If I were to assume for hypothetical purposes, I would think that maybe (just maybe) the cost of the extra heavy rail is worth it because it still last longer than the lighter stuff and so the lighter stuff would be more expensive because it requires sooner replacement and more maintainace.

[Overmod]

I've done partial versions of this analysis, both for 'fantasy railroads' and for actual segments. One variant of this approach that can work is to schedule 'speed slots' for different times (dayparts, days, etc.) that apply to specific segments of railroad. You see a sort of version of this on the NS Birmingham line west of Austell, where a bunch of freights are stacked up to run behind Amtrak, in order of priority/speed capability. My understanding is that yard or run-through capability is factored into "speed" and of course this determines what the true 'critical-path' track speed for any given set of trains will be in a proper model. I'll return to this in a moment.

Single-speed running can be greatly assisted by certain types of ICC-style regulation, when it sets a price for commodity carriage that is high enough to 'amortize' the larger running costs that can be marginally assigned to higher speed. Perhaps needless to say, it can be greatly assisted by better terminal management, good PTC, and the adoption of reasonable scheduling, the discipline to maintain it, and good back-end shop and ROW maintenance to make things work.

It is greatly hampered by problems with equipment, particularly problems with foreign or bad-order equipment which cannot be handled quickly and effectively with relatively low-cost procedures (e.g. flat wheels or problems with trucks or truck design). As Dave rightly points out, a wide variety of factors (including both Murphy and Finagle) conspire to 'increase the entropy' associated with your scheduling, and the closer you approach capacity -- or perhaps, to put it a bit differently, the Hirschmanian 'slack' which your higher-speed operations have provided in maximum capacity -- the more effect these factors will have, and the more rigorous you will have to be to recover from them.

Students of foreign railroading may already have noted that some high-speed railroads conduct their 'lower-speed' (or more-frequent-stops) operations at night, or at times when no fast operations are scheduled. There is an interesting sort of implicit analogy (for operations) on systems that do time separation for non-FRA-compliant traffic (e.g. NJT light rail).

A point to remember is that a train that runs fast may NOT run fast over its entire route in order to gain the benefits of fast running. This is not just a matter of least cost in infrastructure (cf. some of the wacky trackage on PRR through the Philadelphia area) -- note what the 'optimal' speed regime for a luxury train like the California Zephyr is when the trip involves more than a full day's time. The ability to run fast is an important, perhaps critical, component of making up lost time for scheduled-time deliveries or turnovers, but it does not necessarily follow that the ability to run fast anywhere, 24/7, is comparably important...

The length of route for critical dayparts is significant, as is the ability of the 'ends' of route segments to source, handle, and 'turn' equipment properly. Just as jet speeds are essential in getting something like the FedEx distribution model (or many of the multiple-route-with-a-single-aircraft operating models) to work, higher corridor speeds can greatly increase the equipment utilization or number of potential revenue or scheduled movements per train or trainset. Perhaps more importantly, crew time and scheduling become better, which in turn may improve morale and retention (and contribute measurably toward having more of a 'real life' even with high call rates!)

But as the segments grow longer, the maximum permitted speed even for sophisticated train and track systems increases to frankly unjustifiable levels. While I have never thought it sensible to segregate high-speed passenger and intermodal freight even in FRA high-speed-optimized corridors, the situation is very different for mixed freight. Even sustained speeds in the high 80s are impractical for equipment with undamped suspensions -- let alone the 110mph corridor speeds Amtrak is discussing. This means that there are at least two separate criteria that must be used to schedule multispeed 'time-domain-multiplexed' railroad operation:

Windows for high-speed operation, following scheduled Amtrak segments at decrementing speeds or priorities, vs. end-to-end services at lower speed (including 'peddler' on-line traffic) outside those windows;

No traffic that has a detrimental effect on either scheduling or infrastructure condition (e.g. no running interchange cars at speeds that damage the track or cause derailments, etc.)

One potentially interesting model involves the building of multiple CTC sidings, with separate throats, at wider spacings on key main lines. These work a bit like distributed transfer yards in that they allow 'bunching' of traffic in minimum time to allow fleeted opposing traffic to pass easily. *Given higher track speed on intervening line* this allows much less civil engineering to provide increased capacity in many areas where geography imposes bottlenecks.

[Junctionfan]

In addition to this, I would add that it might be better to uses PTC /PTS instead of the current CTC signals.

The ideas of making the speeds higher in my mind, is to eliminate the need for dwell times in the yard. If it normally takes a mixed freight without speed restriction from consist, 4 crews worth, wouldn't it be great if you could make it so that the train goes faster so it only requires 2 or 3? This means that you have 1 to 2 extra crews that you already had, to be redistributed to other trains to reduce congestion from too long in terminal dwell times. If you run a line with say 50 trains and it takes for ever, if you implement higher speeds on the rails and make crew changes less frequent, you have about 100 crews right? Those 100 crews can be put to use else where to avoid the long in-terminal waits. I guess it is why states and provinces call for greater speeds on the highways to reduce conjestion-because it makes people get to where they are going faster and makes more room on the highway.

[Junctionfan]

I understand that someone has to pay for it, that's why I stated that the traffic would have to justify the investment-no sense making those kind of improvements with lines of 12 trains a day. My suggestion was for the lines that see 70-100+ a day or for the lines where there maybe know room for passing sidings which I should have explained and is at capacity or close to being over capacity.

My theory was, my suggestions would save on having to hire extra people (use what crews you have), maybe reduce maintainance (heavier rail idea), increase on-time performance (reduction of in terminal waiting) and reduce some other costs too. I was hoping that with all said and done, they would still save money-maybe alot of money. Again not knowing the costs of all this, it is only speculation on my part.

[Overmod]

One very significant point about PTC is that its use as a 'safety' system (although politically significant) isn't really more than incidental -- one of the reasons that PTS is more or less a scam if implemented only as such.

The real purpose of the system is to increase 'safe' capacity by decreasing headway, giving better control of operations, allowing integrated computer assistance, etc. THAT is the criterion that ought to be used for investor-responsible companies when looking at systems -- It's NOT about keeping trains from whacking into each other. One -- not by any means the only one, imho -- reason why the NAJPTC object model is so riddled with wacky contradictions is that its implicit premise was safety restrictions, both operating and civil, and no coherent operations optimization was in the design process. A bit like concentrating education spending on remedial education, and not looking at improving gifted-student programs or at optimizing learning for 'normal' students...

[Junctionfan]

QUOTE: Originally posted by M.W. Hemphill

It's looked at very closely, Andrew, trust me.

From an operating perspective, I'd rather never, ever, put a train into a siding on a multiple- main track railroad, because it adds uncertainty. I'd rather keep it moving and worry about doing the overtake in the next terminal, where everything is probably going to be delayed for inspections, crew changes, block swaps, etc., anyway.

Here's just some of the problems with putting a train into a siding for an overtake. Is it a siding with any grade crossings in it? If it is, it starts to become worthless. Will the switch throw when you need it to? What if there's snow? Or blowing sand? Will it get into the points and prevent it from throwing, or almost as bad, show an out-of-correspondence condition? What if the CTC goes down just then -- how long will the delay be to talk the train past the absolute signal? Can the train get stopped and started without drawbar or air problems? Where is that siding, anyway? is it in a neighborhood filled with vandals and thieves, or just people stupid enough to crawl under the train to get to the other side of the tracks? Can I ever get the train back OUT of the siding, anyway, without just placing it in front of something else that wants to run faster than it?

What generally happens, when you start to use sidings for overtakes, is that once the train goes in, it never comes out. The capacity shortage that led you to put it in there in the first place doesn't go away the moment that train gets off the main track. You just moved the problem backward a bit. Plus, the time you burn up just slowing down for the switch to get into the siding, and to drag back out, is quite substantial, and that creates capacity shortage all of its own.

Keeping all trains moving, even if they're a little bit slow, is almost always the better idea. Overtakes are rarely worth it unless you can do them in a slack period.

I don't understand why passing sidings exist than. I understand why you may not like passing sidings but I mentioned about having a triple or more track mainline before and I was told that it wasn't justified or made economic sense. CP and CN have tons of passing sidings and they don't seem to get bothered with them (mind you some of passing sidings have had to be lengthened on the CP Galt Subdivision (Toronto to London Ont) and CN Halton Subdivision (Burlington Ont to Mac Millan Yard) because of the length of the trains increasing.)

I figure that CSX would do a lot of this particularly lines around Fostoria, Deshler and "Florida Funnel" because of the traffic so this wouldn't be too much of a problem. As for the switches, don't they have manual over-ride? If the switch machine fails to automatically switch them, isn't their a signal that informs dispatch that the switch has failed?

Now one thing I have to ask just in case I'm not getting it; are you saying that overtakes are rarely worth it when using directional traffic or non directional traffic? I'm just thinking about CSX again in some areas like along the Willard Subdivision and the Colombus Subdivision.

[Junctionfan]

Thankyou Mark,

Alot of what I have been saying is from watching CSX in action at Fostoria. First time I have actually witnessed major conjestion that required what I call "planned dispatching" on F tower's part.

I also have listened to the scanner from the Fostoria Live site and found that they seem to do a lot overtakes at least when their UPS trains enter the territory. They do have sidings "through yard limits" at East Fostoria and I believe at Godsend as well as the B&O yard south of the diamond and maybe one north passed the CSX/NS diamond.

Now of course this is a junction but a tremendous amount of scheduled trains plus some as required stuff go or come from Chicago; that's after they go through Deshler. I'm just fasinated how they manage to keep things going without adding another mainline to an already double track mainline.

There are a few BNSF and UP lines that seem to have what I call "junction merging" where several lines come together to form one busy line like the UP Sunset line between El Paso and Los Angelas for example and wonder how they manage to do it without doing even half of what I'm puposing.

[Junctionfan]

That sounds like a place that requires speed increases to at least 40mph. What is the ventilation like and track conditions?

[dehusman]

Normally you don't put sidings on a multiple main track line. You also have to remember what putting a train in a siding does, it now doubles the number of slower trains the next faster train has to overtake or meet.

Dave H.

[daveklepper]

I've learned a lot by reading the responses, with Overmod's (and of course Mark Hemphil's) being the most instructive. Note that I don't think a coal company has to pay more to run its unit coal train at 50 mph than at 25, because of the tremendous saving in CREW COSTS. And the fuel savings of running at 25 might well be eaten up by accelerating out of sidings. The comparison with highways and autos is not, bu the way at all applicable. What I learned from Ballsbaugh's course is that private cars have the maximum lane capacity at 22mph! Because of reaction time and safe stopping distance. 40 mph or 45 is generlaly considered a good speed limit for highwaysa where you want to maintain reasonable speed and still move the most traffic. A railroad with block signals or more sophisticated ATC and cabi sginals is something quite different. And of course inherently a lot safer.

[oltmannd]

Can't beleive nobody mentioned fuel and equipment costs as part of this equation!

If you powered coal trains at 2 hp/ton to operate at 70 mph on the level, the fuel penalty would be huge. You'd have to be able reduce equipment cycle time enough to pull out at least one train set to get back the money spent on fuel and locomotives. It's not likely that you'd get too much in the way of crew savings unless you had enought volume to set up new crew pools or had could use existing multi-district "long" pools.

In most cases, you're talking about doubling the number of locomotives on the train - at $2M a pop for locos, that's a big hit on the cost side of the equation, too.

[dehusman]

You wouldn't get that much in crew costs because you would still have the same number of crew changes. The modern crew districts are already way larger than the steam era predecessors (closer to averaging 200 miles than 100 miles in the steam era).

A coal train normally runs at .8 to 1 hp/tt.

Dave H.

[oltmannd]

QUOTE: Originally posted by dehusman

You wouldn't get that much in crew costs because you would still have the same number of crew changes. The modern crew districts are already way larger than the steam era predecessors (closer to averaging 200 miles than 100 miles in the steam era).

A coal train normally runs at .8 to 1 hp/tt.

Dave H.

....there are still some "not so modern" areas here in the east.
...and some place that went "backwards" after 6/1/99.

[:D]

[Junctionfan]

I think that if speeds are increased and the crews are worked 8 hours a day, you would cover far more territory and it would save on labor costs which might out weigh fuel costs.

Even if one speed is not achievable, trying to raise 20mph speeds to 40 or 50mph would be better. El Paso seems to really need it. How much time is wasted going 20mph through a busy line like the Sunset line?

[Overmod]

Oh, for heaven's sake, the 20mph section isn't more than a few miles long -- IIRC it's just a trench that allows the route to cut across part of El Paso without lots of grade crossings, etc. If this section is, say, 15 miles long, tell me the difference in time that it takes to traverse it going 20mph vs. 40 and 50 -- then tell me if you think that's relevant to the overall trip time for common run-through service...

Note that with proper PTC, the permissible headways 'prepared to stop' would be right in line with the time separations needed at track speed (so there's no real 'bottleneck' imposed by the lower speed). I would not think this section constitutes as much of a bottleneck as some of the areas further to the west.

Naturally, directional-separated double track would be a significant advantage in this area, and triple (or even quadruple) track to allow overtakes at this point perhaps even better. I do believe that what they have provides "adequate functionality"... if for some reason the western portion of the Sunset Route were to be increased in capacity, it should not be too difficult to expand.

[Junctionfan]

Do they have the room to build extra lines? It seems to me it would be cheaper to raise the speed limits than add track and enlarge a tunnel.

[daveklepper]

I am not saying that 70mph is THE speed for every main line. A lot depends on the traffic mix. But that huge fuel bill to move the coal train along with the rest of the business might look prettty small compared to the savings realized by lack of delays and generally smoother operations by the one speed approach.

I think that capcity at 70 mph would require some estimation of stopping distance. Would two miles be sufficient for a mile long train? if a very advanced "moving block" cab-signal system with good ATC were present, we could probably safely schedule a train every 7.5 minutes, giving 8 trains an hour, 192 a day. That is in one direction on a single speed double track railroad. With regular block signals and some automatic stgop protection, every 15 minutes would be snap, wiht 86 a day, still not bad! Of course this would be reduced by msintenancce times, fluctuations in business,etc.

[Junctionfan]

Is there any large abandoned yards that could connect to the SP line near El Paso?

[kevarc]

Good one Mark - I really do not thing after they got the Cotton Rock they did many smart things. I think they were too busy trying to patch all holes to keep the ship from sinking (so to speak) than really take a long term look at things.

I have always wondered why they never moved the refueling station somewhere on the Lordsburg Sub to get it out of Texas. But there may be things that we do not know, such as availability of land (though that really should not be a problem, you never know), taxes, and somewhere for the people running the place to live.

REducing crew costs - Crews are not paid by the hour, generally, they get miles that their pay is based on. So running the trains faster would not reduce costs. The BNSF has reduced the crew costs on the Transcon, by removing just about every other crew change. i.e., they stretched the crew districts.

Faster - sounds good, but the added fuel costs are a killer. That is why the UP derated the fast 40's. And BNSF has been slapping speed limts on the older SD40-2 fleet because of fuel costs. And when the faster trains get to the bottleneck - well - you still have the bottle neck.

It sounds easy, add capacity. But it not as easy as it sounds. Not only do you run into the existing infrastructure, as Mark stated about El Paso, you run into capitol costs. And this is again another killer. Remember, after you have the capitol costs, you get the yearly maintanence costs. While I am not exactly sure of the incremental maintenence costs for adding track, it is not cheap. And to run the faster trains as you statred, you have to significantly upgrade the trackwork itself to meet the FRA track standsards for 70mph traffic. And coal trains just beat the hell out of track at high speeds.

And the RR's are under attack on Wall Street for the poor rate of return of capitol, so they must balance capitol costs with recovery of those costs. That is not that easy.

Standard and Poor's transportation analyst Anthony West noted in his report that while earning continue to lag behind the cost of capitol, "the railroad industry is moving closer to acceptable profitablity as its cost oc invested capitol has fallen to 10%, from 17% in 1981."

[Junctionfan]

Wouldn't it be cheaper if the railroads payed the crews by an annual salary than? Would the workers / unions go for that?

[kevarc]

Probably not, the contract for RR'ers is unlike any other in the US. Plus each local may have special conditions and other things. It is extremely complicated. And the union is loath to change things for fear that the men might loose money, benefits, etc. A long. long time ago I was a member of the UMW and that one was bad enough.

[FThunder11]

I like the idea, but it an have some pretty major flaws

[Paul Milenkovic]

About those 70 MPH coal trains:

John Kneiling argued in Integral Train Systems (Kalmbach) that fuel is one of several costs, and one of the big costs is the lease payments on the rolling stock. Time is money, and while running the train slower saves on fuel, it makes the train less productive, and those lease payments come due at a constant rate even when the train runs slow.

While the aerodynamic drag goes as the square of speed, a coal hopper (average of loaded and unloaded return trip) is pretty heavy for its bulk so rolling resistance is an important factor, and my back of the envelope calculations indicate that going at 60 MPH uses about 2 times the fuel (not 4 times if aerodynamic drag were the only factor).

So at 60 MPH, you are burning twice the fuel per mile but using half the rolling stock lease payment per mile. If car lease payments (per hour at track speed) are more than your fuel payments (at track speed), you are not running that train fast enough.

If I can get answers to these questions (I looked hard on the Web to no effect), I can put some numbers to back up why Kneiling wanted to run coal trains at passenger train speeds and why this is true today, even with high oil prices. What is the modified Davis formula for train resistance with roller bearings -- Davis' formula was for journal bearings? What does a 100 ton coal hopper cost these days? What is interest rate charged by folks who finance rolling stock?

[Overmod]

Oh my Lord, they put the fuel station WHERE?

Simple-minded objection, schedule trains to fuel 'alternately' so you can at least run by the bottleneck -- but there are doubtless operating reasons why that doesn't work.

Which brings up the question of whether an investment in faster fueling technology might pay very real dividends -- multiple fuel ports on a locomotive, positive locks and seals, foam recovery, pressure fueling a la NASCAR, more than one fuel attendant, etc.

Back when I was young and fairly dumb, I considered whether 'in-flight refueling' could be done on critical trains -- I invite readers to comment on the reasons this idea will not work for long...

I would tend to concur that shifting the fueling point westward, even locating it in the (considerable!) mileage in Texas west of El Paso on the Sunset Route main, would allow solution of most of the logistics issues. Presumably the method by which the fuel arrives at the depot (pipeline?) is a major factor... how could this be made workable for "less central" locations in the El Paso area?

[kevarc]

The new BNSF one in Idaho uses railcar storage for deisel. gets away from UST and the attendant problems with them. This is one area that I think BNSF is far ahead of the rest as far as refueling and servicing through trains.

It would be hard as you have 3 different tracks coming in from the east and they all work on their own dispatching and such. Another nightmare.

Paul - us train simmers have been working with the friction problems for a long time to give the cars more realistic parameters. At www.3dtrains.com/forums we have a dedicated forum for physics and this has been discussed there in great detail, but any new thoughts and ideas are never truned away.

While the section in El Paso may only be a few miles long, that is all you need to screw things up. RR history is full of things, such as gaunlet bridges, short single track section that mess thing up badly.

[TH&B]

45mph max with 30mph "high speed switches and crossovers" for all trains. A 60mph freight will consume more then twice that of a 30mph train. Keep the max speed on the lower side to save fule on the heavy trains but keep the speeds constant.

Accelating a heavy freight to 60mph only to slow down to 15mph for a tunout or 10mph for a restricted speed and lengthy stops lowers the average speed imensly. Bulk shippers want consistancy more the top speed service.

Hi speed freight realy is a waste of expensive equipement because there are other modes that travel faster easier. Over 60mph you'll be pushing alot of wind resistance and paying for it or the costs to streamline a coal train when none cares how fast it's
going.

[oltmannd]

Typical 90 car coal train on Conrail Pittsburgh line:

loaded 30 mph - 2.8 gal/mile
40 mph - 3.2 gal/mile
50 mph - 3.8 gal/mile
60 mph - 4.4 gal/mile

empty
30 - 1.3
40 - 1.6
50 - 1.9
60 - 2.2

Note that this route involves some heavy grades. Speed would have a greater % impact on a flat route.

[oltmannd]

A couple more thoughts/opinions:

1. Many times, the restraint on capacity of a double track mainline is entry/exit to terminals, not the track speed of the mainline. The added capcy that you'd get from flowing all traffic at the same speed cannot be supported by teminal entry/exit flow rates in many cases. (the west end of the NS Chicago Line is a good example)

For example, if a train yards at 15 mph, it will take 8 minutes to clear a 2 mile long block. With 2 blocks between trains, that's a train every 16 minutes or roughly 4 an hour each way. Out on the mainline at 60 mph, that's 15 mile separation. If you try to do more than this, they'll bunch up a the terminal.

2. Mainline fueling is one of the stupidest things going. Why one would chose to stop locomotives, complete with trains, on some of the most valuable track the RR owns is beyond me. Locomotives spend a lot of time doing nothing between assignments - that is the time to fuel them - not while they're busy with a train! It's lousy asset utilization interms of the track and equipment. I think it came about in an effort to economize locomotive fueling by having a few high production locations instead of a lot of little ones - this in a time when there was excess mainline capacity -and a time where RR depts tended to act independently from each other. Mechanical might act in the interest of their budget even if it killed Transportation's.