The following text, questions and answers and photos are samples of the Technical Papers presented at the NISA Spring and Fall Technical Seminars.
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BNSF Trough Car
I would like to begin by thanking you for the opportunity to speak to you today. The subject is a little bit new and something that we're very anxious to get out to people for their comments and suggestions. The first thing I will talk about is a type of car that does a multitude of things for the mines, the receivers, and for the railroads themselves. This flexible coal car can be used in rotary dump service and in bottom unloading.
The standard 100 ton car has standard 100 ton trucks, wheels, and couplers. It is made out of steel and can be maintained with existing people in existing facilities. It has the strong backing of our mechanical and operating departments along with our coal marketing people. This car can be easily loaded and weighed. This is the car that everybody likes, including scale people like yourselves. This car is flexible, everybody likes it, and its been around forever. Why would we want to change if everybody likes this car so much?
This is the explanation for getting away from the car that everybody likes. It boils down to economics. We are doing alright with the standard steel car, but we think we could do even better with new designs like the aluminum cars and the 286,000 pound cars and cars like this trough car. I would like to demonstrate with this table - See Figure 2 - Train Tonnages/# of Trains of basic steel hopper car train as it leaves the Powder River Basin. This train is based on 263,000 pound gross rail load for each car and a total of 11,600 tons of coal for the train.
We ran this comparison on one service that we have that's running 3.4 million tons per year. The BN needs to operate 292 trains to carry that amount of coal to the power plant. Using the same car carrying 270,000 pounds in an overloaded condition will allow us to carry 3.5 percent more coal per car. This results in more tons per train and reduces the total number of trains per year. Likewise, the aluminum 270,000 pound high side gondola car and the 286,000 pound high side gondola car allow us to carry still more coal per train. We're now carrying in the range of 2300 more tons per train compared to that of our standard steel car fleet. The total number of trains needed to carry the 3.4 million tons of coal per year drops from 292 to 242 resulting in a reduction of 50 trains per year.
The Trough Train is shown in four different designs for comparison. The truck centers and an aluminum design offers some tradeoffs in carrying capacity. The key to the economics is explained using this table. The train as we envision it would be made in the trough design and out of aluminum. The amount of coal carried would be increased by roughly 3200 tons per train. That turns out to be 44% more coal per train and reduces the number of trains by 91 in this particular service.
Our railroad has been sized without a lot of overcapacity. For us to be able to carry 40% or even a conservative estimate of 30% more coal without increasing the number of trains that we need to operate is very attractive. We believe that some of the mines we work with have their capacity set by their loading loop design. To be able to ship or receive 30% or 40% more coal while still receiving the same number of trains is attractive to them also.
We get this benefit two ways. First, the trough car carries two and one half times the gross weight of a normal car. It has ten axles, each using 100 ton components. We are loading this car to the normal 263,000 pound capacities. The car will not be overloaded in any way. When we take these ten axles, carrying the same gross weight of two and one half cars, we're carrying it in 21 feet less distance. This will give us the ability to carry the load of 143 standard coal cars in the train length of a normal 115 car train with a length of 6100 feet.
Second, the light weight of this car is so much less because there is that much less structure involved. We get additional benefits because of the lower tare weights in that we can carry additional coal in the place of what would have been the car's weight.
There is one prototype car on our property right now (See Figure 5 & 6) that has been making the rounds for people to see. The car is a five section car at a length of 110 feet over pulling faces. Again, all the components are standard 100 ton parts used in conventional service. The car is a little high at 13 feet and has longitudinally operating doors. The doors are roughly eleven and one half feet long and have an automatic unlocking mechanism. The opening is eleven and one half feet by two and one half feet and is on both sides of the car.
A lot of care has gone into the unloading of the car. This car can be unloaded on a trestle type of unloading system or dump through the rotary dumper. This car is not designed to be rotary dumped, however, we would dump through the dumper structure to the hopper below. This may require the floor plates to be pulled up or modified slightly. The dumper, in this case, would be used as a bridge. This gives us the ability to dump in either unloading situation.
These two five section prototypes will probably be the only ones that will be bought of that configuration. The prototypes will be tested fully, and we are in the process of doing that now. The testing should be completed in the next year to year and a half. At that point, we intend to buy one train set. The train set would be composed of thirteen section cars. It may not be evident, and I've yet to explain one of the main features of this car, in that there are no interior ends on either the five section car or the thirteen section car. There are bulkheads at each end of the car, but nothing in the 276 feet between bulkheads. From a loading standpoint you are just loading a large open area.
We intend to go to the thirteen section car, but it's important to note that the design of this car is still flexible as far as the specifics. We are testing the basic building block now and we've found that we can increase the length of the car in building blocks of four. This means that a five, nine, thirteen, or a seventeen section car is a real possibility. As I said, the thirteen section car is most likely what we will be leaning toward. We are looking for the systems to properly weigh and ship a railcar of this size.
Let's take a look at some of the specific details of the car. There is a white crosshatch on each of the doors. There is a safety consideration with the doors opening out from the car. Someone standing next to the car and not expecting the doors to open could be hurt by the swinging door. At each end there is a single axle truck and conventional two axle trucks in the center positions. The single axle truck at each end of the car is consistent with all designs of this car.
Why did we go for a single axle? In the economic justification for this car, we tried to compress the train and put in more coal per train length. With conventional 70 ton trucks at the ends, there is no way to load them to full gross capacity. This adds another five to six feet to each end of the car that's not useful. We decided to use the single axle so that it can be loaded to full capacity.
The car is equipped with a hot shoe system. The doors are unlocked by an electrically controlled air piston system. You hit the hot shoe with a voltage potential, as you would with any rapid discharge car, the doors will unlock allowing the weight of the doors and the weight of the coal to actually open the doors. You reverse the potential on the hot shoe which resets the doors for locking. In the beginning the doors are going to be manually closed and we're in the process of designing a ground mounted door closing system that automatically closes the door as the car goes past it. We expect to have that system in place later in 1991 or early in 1992.
We've spaced the trucks to avoid overloading. The wheel to rail interface has not been compromised with this design. Standard 100 ton wheels are used, but are closer than that of a traditional train set. This has caused some concern with the long span bridges. For this reason, the design has been changed to accommodate the maximum loading these bridges will accept. This is how the twenty one and one half foot truck center dimension was determined. When we pushed a little on those bridge people they came back with a twenty one foot even truck spacing and this is being used in the thirteen section car. For now we'll keep the limitation based on the long span bridges, primarily those bridges over the Missouri River and the Mississippi River.
The articulated connector is buried behind the car structure itself. There is a hand brake wheel mounted on the side of the car and a electric control box for operating the door lock. There is a manual discharge button in this box to allow unlocking the door without the use of the hot shoe system. Side plates slide against one another to form the articulation over the truck centers. The floor plates are constructed the same way and were designed for a twenty degree curve. Most loading and unloading loops are in the range of seven to eight degrees. The car has inadvertently gone around a 38 degree curve without derailing and taking only minor damage. We don't intend to do this as a regular coarse of action.
This is a Burlington Northern design. We've gone to a lot of trouble to design this ourselves and we've used some outside consultants to help flesh the design out. Bethlehem Steel has built the first two prototypes but we are in no way obligated to them contractually to stay with them. We have the ability to take our drawings any place and having this car built. It is a Burlington Northern proprietary design. In all truthfulness we intend to make this car a integral part of both our marketing strategy and that of the mines we serve in order to get the coal out and to extend our market reach and theirs.
Questions and Answers
Q. Do you expect any frozen coal problems or other problems related to getting coal out of the car?
A. We don't expect to have problems, but we don't know for sure. We are placing the first car in North Dakota. It will be loaded in Buella, North Dakota and sent over to United Power plant in Stanton, North Dakota. North Dakota gets pretty cold but it's only a 36 mile round trip and it may not be long enough to freeze the load in. We will have it exercised twice each day in that service. The door is 2 1/2 feet wide and 11 1/2 feet long and everything on the inside of the car is 45 degree slope sheets. We hope it's going to do well. There is another factor in that the car does have smooth exterior sides, meaning the posts are to the inside giving more area to freeze. We've painted the car black, not just because we like it that way, but because this will absorb some radiant energy from the sun. It's one of the things we'll be looking at closely. When you consider the amount of doors you have on a regular car and the size of those doors you'll see we've given ourselves a good fighting chance to avoid stuck coal.
Q. Will a thirteen section car have one car number and one tare weight?
A. Yes, we're pushing 1,709,500 lbs. in gross weight on the thirteen section car. The five section car carries a coal net weight of 260 tons.
Q. Have you considered the unlikely event of a derailment of your thirteen section car?
A. We have. That's part of the reason I keep body guards against our transportation people. We're concerned about that also. This idea began with a consideration of the economics. It was shelved for about a year because we couldn't figure a way around the derailment scenario. Even worse would be to loose a wheel to a hot box and you've got to change it on the road and we wouldn't be prepared. We're making provisions to handle this, not in any kind of easy manner, but to get the job done. And as far as the derailment scenario, the answer finally came where we would take a D9 Bulldozer and you push everything into the ditch. If the economics can't substantiate that or if you have derailments too frequently or if we have hot boxes too frequently it will kill the idea flat out because we won't be able to afford the extra expense that's involved with that. At the same time, with it's short truck centers, it's like a little centipede and should be better than our standard coal fleet at resisting derailments.
Q. You talked about roll-over dumpers. Do you have a plan to keep these away from rotary dumpers?
A. We intend to use this car in a rotary dumper. We are asking the receivers of the coal about their dumpers and we have intentions to pull the floor plates on the outside of the rail and using the dumper as a bridge with the coal discharging outside the rails and into the collecting hopper below. We are working with a trestle unloading system to receive coal from Black Thunder Mine. One dumper is being modified at this time to handle these cars.
Q. Does the modification to the dumper render it useless for standard fleet?
A. No, it's transparent for the standard fleet. Again, all we are doing is pulling up floor plates so these cars can unload and put back in place after the cars are gone.
Q. What are you doing with rates?
A. I'm not in a position to talk for our coal marketing people. I can tell you that the prototype service is having the per diem waived on the car as we are supplanting this customer's own fleet. They are not going to be penalized by having his cars sitting out. Otherwise we are considering it a 250 ton car and prorating the billing based on the existing rate structure. It would be silly to say this wouldn't effect the rate sometime in the future, but we don't know just yet.
Q. Is it possible to overload this car or is it designed to be full at capacity?
A. We've designed it so that it's going to be pretty hard to overload it. We are counting on a heap to get this car loaded. One thing that will be possible is to overload the end. There is too much capacity over the single axle truck. As you would normally load a car, a void would occur at the end which will prevent the overload. We are counting on that void near the end of the car.
Q. Are you expecting any coal to leak through the articulation?
A. No we don't. We have a couple of things being considered. Burlington Northern does have this design, but they do share the patent with a aggregate hauling railroad in Georgetown, Texas. These guys have been hauling aggregate rock (sub-ballast type material) with this design. They haven't had any problems and we don't expect to lose any coal that way. As far as coal blowing off the top, I don't think we would be any better or any worse than what's already out there.
Q. How do you intend to weigh these cars?
A. This car needs a truck scale system. We need to work with the scale manufacturers to change the software to distinguish a five section and a thirteen section car. The mines that I've seen out in the Powder River Basin have got long approaches and are usually concrete for 150 feet on either side of the scale. As long as everything is level or on a constant grade, we don't expect any problem at all weighing this equipment. This is being checked using the prototype cars. Burlington Northern has been pushing really hard and has been working with the mines to develop batch bin systems. Batch bins with this particular car are going to offer some opportunities for the mines to figure out the best ways to handle them. We haven't scared people off with the batch bin systems but it will take some novel approaches to actually weigh them that way. The belt scales will perform better with the long open area. We're working with the mines and we are expecting feedback on how they're handling the loading. Because the car is one big piece it cannot be broken into different car numbers and different tare weights. One other thing that we're going to need to watch is the loading of each section. It goes without saying that we don't want the lading of the five section car in the first four sections. Guidelines will be provided to the mines to get these cars loaded evenly.
Q. If the coal gets frozen at the articulation, could it stiffen the car enough to cause a derailment or other problems?
A. There was a two section articulated car similar to this in the past. That car was loaded with coal, had water poured into it, and they didn't have any problems with the articulation. In our case, we believe it is less critical because the truck centers are a little bit shorter and therefore the angle of the curve is that much less. The Georgetown Railroad operation packed the aggregate into their car, watered it, and took it around a twenty three degree curve and had no problems. They have video pictures of how the load arranged itself in the curve.
Q. For testing our ability to motion weigh this car we must establish the static weight. Has there been any thought on how to get a reference weight on a car that is 110 feet or 250 feet long?
A. We have not had any volunteers to build a 260' full draft scale. We intend to multi-draft static weigh this car to determine its reference weight. With the power plants enthused about getting the coal they're paying for, we've got to address that problem head on. One of the things that I might suggest is that the articulated connector works like a slackness drawbar. They've got a wedge system in there and as the components wear the wedge drops down and keeps the connection slackness and accounts for wear. If there's any possibility of load transfer the variations have been well within AAR tolerances as far as scale tolerances are concerned. But to prove this technology, we would like to pop those wedges up inside the connector, eliminating any possible transfer of vertical force through the connection. That's the way that we would like to prove that this is a working system.
Q. Are you suggesting that the wedge may need to be pulled to get a good reference weight?
A. No, what I'm saying is that there will be no transfer with the wedges down. In order to prove that, I think that we would be willing to pop these wedges and make sure that the weight doesn't change.
Q. Is there a type F coupler between the sections?
A. It's the same type of connection that is used in double stack cars. One section has a female portion, the other section has a male portion and when connected, they both rest on the truck. This is a way of tying both sills together without any type of coupler at all. Between the cars themselves we are using an <169>F<170> coupler.
Q. Do you intend to interchange this car?
A. We expect this car to be in dedicated service. There have been some liberties taken in the car design. For instance, we don't want this car to be humped. There is a similar car used by the Santa Fe. It doesn't have the same articulation, but the AAR requires the car to withstand a 1,250,000 pound impact and this car won't handle that let alone the thirteen section car. It will be in selected service and in dedicated trains of its own type once we get past the prototype stage.
Q. Are you going to restrict its use to just coal?
A. We're concentrating on coal right now. There are enough questions where we don't want to get too crazy and apply it to all sorts of different places at this point. I think it pretty obvious if we can make it work with coal it won't be that much trouble to put a top on it and use it in covered hopper service. There is no other chunk of our business that provides the kind of opportunity as the coal fleet.
Q. Will your repair facilities be able to maintain this car?
A. We would prefer a drop pit to change the wheel sets. We're planning to put some money in for drop pit tables in order to support this car.
Q. Do you anticipate any problems trying to start this train without slack?
A. There have been a couple of trains equipped with slackness drawbars. In basic five or ten car groups and they provide this slackness environment also. One of things that was done in the past was to stop those trains on a 1.3 percent grade and have it start from a standing stop with existing power. There wasn't a problem in this case. The characteristics of a diesel locomotive are such that they'll pull the most at very, very slow speeds. We feel that we're not going to get one of these trains stuck on a hill, at least not in a place that we wouldn't stick a normal train.
Q. Won't you end up with gaps with a conventional volumetric or bin loadout system?
A. Black Thunder is a perfect example bin loadout system. We told them the car makeup and the volume to be loaded, and let them tell us the best way to load it. I think they are talking about loading from multiple bins and maybe using their topoff system to even out the loads. They will try and probably make adjustments to the loading procedure as we see how it works. We may dump straight from the silo and weigh the car after the loading.
Q. Do you use wear plates inside the car?
A. In general there are no special wear plates on the car. The inner floor is at 45 degree angles. At the articulation we have sliding plates on sliding plates. We are expecting some wear at this point. When we looked into the cost of using manganese steel for its wear characteristics we decided to throw away the standard steel plates when they wear out. Also, we're looking at a plastic plate for one of the articulation plates. The outside plate would be steel for it strength and the inside plate would be plastic for its wear ability.
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