BNSF tests on Electronically Controlled Air Brakes

[jeaton]

Trains November 1996 (seems like yesterday) reported on the Santa Fe's testing of electronically controlled air brakes installed on a train of TOFC/COFC flats.

The 1996 BNSF Annual Report also mentioned the test, noting that train stopping distances could be reduced by 35%. I believe that the Trains article explained that the system would allow a reduction of brake cylinder pressure so that braking effort could be reduced without a complete release. I think that provides for improved speed control on down-grades.

I would guess that this would provide some additional capacity out on the road.

What happened? Too expensive? Anybody know anything further?

Jay

???

[zardoz]

From what I know of electronic braking, each car in the train would have to be specially equipped with a different type of triple-valve (like the one's used in passenger service) that allow a 'graduated release', or perhaps a triple-valve controlled by electronics, controlling the air, rather than being controlled BY the air.

The advantages that I know of are that the brakes set much faster, at the same time, and with the same force, regardless of where in the train they are.

If memory serves, I seem to recall an old head telling me that the "400" trains had a type of electric braking. And I do remember that they also had cast iron brake shoes. He said you could really stand those trains on their nose if neccessary, but there was a huge risk of wheel-lock, as well as inadvertantly clearing the tables in the dining car.

[Anonymous]

If I understand this correctly, all the cars brakes would need to be changed in order to use the electronic braking system? You could not mix the train and gain, lets say gain half of the benefit?

[Kathi Kube]

It's been a while since I wrote about electronically controlled pneumatic (ECP) brakes (in a former life[8D], but here's what I recall — and please don't hesitate to correct me if anyone else knows more or if I get tangled in the cobwebs in the dark recesses of my mind.

Anyway... One of the major problems with using ECP brakes was that, as Jim stated, every single car would have to be equipped — which means the entire industry would have to purchase new or retrofit every car in every fleet, or no longer able to interchange cars. The only other solution would be to use only specific cars only on a specific route.

I don't know enough about mountain railroading to know how useful they'd be in that setting, but I can assume ECP brakes would help overall train handling.

That aside, the only measurable benefits to using them would be improved fuel efficiency and reduced damage to lading due to shifting when braking. These benefits aren't nearly enough justify the cost. There certainly might be isolated cases where they do, but not in typical common-carrier service.

Besides, at the time the article was written, weren't railroads concentrating more on "gaining efficiencies" through merging with each other and getting a federal nod for remote controls? They put their money where it was mostly likely to make a difference to their investors.

OK. Back to the February issue. You guys do want to have something to read next month, don't you?[:D]

Later,
Kathi

[daveklepper]

There are electrically controled brakes on diesel and electric mu cars. It is entirely feasable to equip freight cars wtih brakes that would be electrically controled when all cars in the train are similarly equipped and revert to regular operation when one or more reduction of air pressure control cars in the consist. Dave Klepper

[Anonymous]

There is enough complexity in todays freight cars already, without introducing more in the form of ECP especially in view of the continuing trend of the railroads to expect longer life from all components that apply to rail cars and thus the reduction in maintenance of equipment personnel.

There could be an applicability for ECP on private owner captive fleets that are used in unit train service, of course it would be upto the car owners to apply the equipment and pay for it, leaving the railroads off the hook.

[jeaton]

Thanks for the responses. Given that all or a substantial portion of the fleet would have to be equiped before there would be practical value, my guess is that the numbers did not work out.

I was mainly wondering if there was any further action, reports, conclusions on the part of the BNSF or any other parties involved.

Jay

[oltmannd]

You have 3 factors to weigh. Cost, benefit and risk.

Part of the cost is simple. How much does it cost to equip all the cars and locomotives? Part of it is hard. What are the extra costs incurred during the changeover period? What's the cost in lost utilization or increased car supply? Do I need to rearrange my train service and increase number of yard tracks to allow for equipped and unequipped cars/blocks?

The savings are almost all "soft", such as increased avg train speed, reduced stopping distances, faster pickup/set offs, fewer train length restrictions based on ambient temp, etc.

The big risk is the reliability of the ECP equipment over the current stuff. The state of the art air brake valve is very reliable. It's design has been honed to a fine edge over the past 100+ years. ECP would be something new and who knows what problems will crop up and what the solutions might be. As goofy as it seem in this electronic age to use air pressure as a control signal, it might be a while until we see a change.

[mvlandsw]

Electronicly controlled air brakes will probably be required for computer controlled operation of trains. Being able to vary the braking instantly through out the entire train eliminates many of the train handling decisions now made by the engineer which would be hard to duplicate by computer.

[ALCOC415]

The rr I work for periodically gets grain hoppers that are set up for this system. The components of the brakes are the same with an addition of a plate that goes between the pipe bracket and the brake valves. I think this is called an interface adapter. Wires run from that to a junction box and then to the ends of the car. The brakes will properly operate with or with out the cable being connected. This was done so that the cars could be run in a regular train or one that has been modified. Also this would be a good failsafe in case the cable broke or was damaged the train can keep rolling.
Dave

[Anonymous]

I know as recently as last year BNSF was testing ECP brakes at TTCI in Pueblo. Talking to one of the engineers involved in the test, it is a great system. But, as has been posted above, the RR's do not want to spend money to convert the entire fleet.

I would look for ECP to start appearing on unit trains before it migrates to the general population

[daveklepper]

I think eventually all cars will be equipped. It increases safety, is not an appreciable per cent added cost to the cars, and actually if used properly can increase capacity.

[d4fal]

It sounds like a great idea, and if reliable, as it does sound, once this system is adopted, I wonder for now if the whole train would require this technology or can a block of equipt cars be controlled. Would that be enough to function safely. I wonder if several blocks were connected removely with regular type cars breaking the solid links, if this could still be used.

It sounds as if the ECP cars should function as well as or better than current technology, and hopefully provide better braking. I would guess that unit-trains could be adopted first, and as new cars and motive power are added to the roster that this technolgy would overtake what cars and motive power there is that does not have this technolgy. As cars and motive power are serviced, this tech could be incorporated at that time. Eventually, at some point, this tech could be manditory.

[CSSHEGEWISCH]

A useful comparison would be the HSC brake that was used on some of the early streamliners. The equipment generally worked well but the entire consist had to be equipped with the system, which would require a dedicated equipment pool. Because of this need, HSC soon fell out of favor.
Unit trains tend to have a dedicated equipment pool, but I have occasionally seen cars with a different reporting mark slip into a given train, which would cause problems if the assigned cars had ECP braking.

[rrnut282]

With the improved stopping power, signal blocks could be shortened to improve line capacity. Unfortunately, that would be expensive to relocate and in some cases redesign signalling. If it is considered as part of the "costs to convert", may doom ECP brakes.

[jrw249]

The bottom line is COSTS!

[Anonymous]

Sounds like it will take an act of government to induce these long overdue changes. A carrot and stick approach should do the trick, e.g. a combination of accelerated depreciation and tax credits as the carrot, and incorporating new ECP requirements via FRA mandate as the stick.

What did it take to get the railroads to convert to standard guage back in the 1800's? How long did it take the railroads to adopt the original Westinghouse Air Brakes?

[M636C]

Some years ago I was shown a cab mock-up for the BHP Billiton (then BHP Iron Ore) AC 6000 locomotives, and I think they said that the braking system on these units was to be set up to control electronic brakes. BHP had done some tests with electronic braking, but have not yet adopted it, even though they have run the "heaviest train in the world" with their AC6000s.

BHP have found that operating Locotrol units greatly increases the speed of brake application, and have tried placing the locomotives at different locations in the train to optimise the effect on braking. Sometimes a single unit has been run on the rear of a train to prevent longitudinal oscillation.

However, most trains just consist of two or three units leading about 100 cars, or sets of up to three of these trains coupled together (two units, 100cars, two units, 100cars, two units, 100cars - this is the maximum the passing sidings allow).

Should electronic braking be implemented, I would think that operations like BHP would be interested in specific brake application tailored to their train operating requirements.

Peter

[jeaton]

I finally took the time to dig out the article "Breakthrough in braking" by Greg McDonnell.

The issue of costs was not discussed, but since the product was then, and appearantly still now, in the development stage, full scale production costs would still be something of an educated guess.

As some of the posts here indicated, the initial set up would allow the electronic operation to be by passed so an equiped car could be placed in a train without EC air brakes. That set-up was listed as Phase I. Interestingly, a Phse III setup would eliminate the mechanical brake valve, the reservoir would be a single chamber vesel and the piping becomes somewhat less complicated. That Phase of designed could only be used at the point when the entire fleet is EABS equipped with at least phase I or II designs. It seems that the Phase III installation may actually have less cost per car than the current non-electronic systems.

Beside improved stopping distances, the article notes that there can be more precise control of speeds on downgrades which, in turn can reduce the time required to transit grades. A simulation suggested that in mountainous territory there can actually be a reduction in fuel consumption. It is also suggested that brakeshoe wear and wheel damage can be reduced.

A final note. The Santa Fe considered that the reduced stopping distances would allow bumping the top intermodal speeds by 5 MPH to 75, and that could be done without a need to change signal spacing.

So that was the story then. Perhaps there will be an update on current activities forthcoming somewhere in the trades.

Jay

[oltmannd]

As I recall reading about ECP braking, the greatest reductions in braking distance came at the low end since you eliminate a fixed amount of signal propogation and control valve reaction time. I think this benefit is more advantageous in terms of reducing running time than bumping the top end up a notch. For example, suppose a train had to operate at restricted speed for two miles when entering a yard, and that limited the train to 10 mph. That move would take 12 minutes. Suppose, with ECP, you could go 20 with the same stopping distances - you'd save 6 minutes right there. In order to save 6 minutes going 75 vs 70, you'd have to travel over 100 miles.

The REALLY big savings with ECP is picking up and setting off enroute. Currently, it can take an hour or more just to make a head end set out because it takes so long to pump the air back up. With ECP, you can "bottle" the rear end of the train, make the set out, couple back up, release and go.

Equipping a car with ECP alone costs about the same as for conventional air brakes, but you have to equip with both to allow interoperability in the changeover period. And, since you have to get a good chunk of the fleet done before you can start to gain the benefits. Delayed benefits can kill an ROI!

The real "missing link" here is the car-to-car communications link. Be it train line wire or wireless radio or infrared, there really isn't any "RR hardened" ready to go system available.

[jeaton]

Don

That missing link problem occured to me. Obviously their can be a fail safe-a break in the wire sets the brakes-but a high level of reliability would be needed. Further, if the system becomes used on everything there is the extra step of hooking up the signal wire along with the air hose on "loose car" train makeup.

Jay

[Anonymous]

I wonder if the introduction of ECP could improve the economics of the single carload market? Maybe the idea of dock to dock service for small customers can be revived?

[Overmod]

Tell me exactly how ECP optimizes dock-to-dock service when applied to normal cars? Even to the extent of recovering its system cost from increased profits?

Intermodal unit trains built for high speed or dedicated service would have electronic brake systems "by default" (almost certainly disc, and possibly air over hydraulic for the actuators, which gives easy antilock modulation without compromising the basic fail-safety of an air system) and would not depend upon consistent acceptance of a 'standard' for interchange ECP for their operation.

More simply: by the time you start considering the kinds of speed range where ECP gives substantial benefits and return-on-equity, you're not using conventional three-piece undamped trucks or rod-actuated brake beams any more, and more to the point you won't really be able to tolerate anything in that consist that has them, *regardless* of how sophisticated a method of modulating the actuating cylinder on a long brake linkage you may have.

If there is a future for dock-to-dock service for small customers, it likely involves intermodal exchange, on the order of a RailRunner system for containers or CargoSpeed for trailers. I'd expect these to be purpose-built, or permanent adaptations of existing equipment, and certainly not something running in 'general' or unscheduled interchange service...

[Anonymous]

QUOTE: Originally posted by Overmod

Tell me exactly how ECP optimizes dock-to-dock service when applied to normal cars? Even to the extent of recovering its system cost from increased profits?

Intermodal unit trains built for high speed or dedicated service would have electronic brake systems "by default" (almost certainly disc, and possibly air over hydraulic for the actuators, which gives easy antilock modulation without compromising the basic fail-safety of an air system) and would not depend upon consistent acceptance of a 'standard' for interchange ECP for their operation.

More simply: by the time you start considering the kinds of speed range where ECP gives substantial benefits and return-on-equity, you're not using conventional three-piece undamped trucks or rod-actuated brake beams any more, and more to the point you won't really be able to tolerate anything in that consist that has them, *regardless* of how sophisticated a method of modulating the actuating cylinder on a long brake linkage you may have.

If there is a future for dock-to-dock service for small customers, it likely involves intermodal exchange, on the order of a RailRunner system for containers or CargoSpeed for trailers. I'd expect these to be purpose-built, or permanent adaptations of existing equipment, and certainly not something running in 'general' or unscheduled interchange service...

There are situations where it would be more efficient for manifests/mainline freights to perform drop off and pick up activities while enroute from terminal to terminal, rather than having small carloads rerouted and backtracked via the local or switch crew. If a certain amount of dock to dock (or siding to siding, if you prefer) can be performed with the time frames reduced via implementation of ECP, why not, especially if it results in more business?