... staring a heavy train, keeping a heavy train moving, or starting a stalled train? This type of thing is very interesting to me. Copyright 2008 Jerry DeBene
Steam or diesel power? While similar in nature, each presents their own unique operation requirements and techniques. Copyright 2008 Jerry DeBene
Check out Al Krug's essay on running the SP&S #700 back in October 2002. He wrote a great description of starting and running a railfan passenger special. He also compared it to his day-to-day experience of running BNSF freights out of Bozeman, MT. Copyright 2008 Jerry DeBene
Either steam or diesel. I know Steam requires more skill but either would be fine. Diesel would pry be my choice tho. Hank, I will check out that link. Copyright 2008 Jerry DeBene
I have never operated a modern diesel. Our diesel locos are of the 1953 ventage. I expect there are some major differences between old and new versions. As I see it, diesels are sort of like a big truck in the way they handle heavy loads, only they have electric traction motors instead of a mechanical transmission. To start a heavy load the engineer selects forward or reverse then moves the throttle one notch at a time while waiting to see if things are going to start to move or not. If things don't move, another notch is in order. The engineer must also keep an eye on the amount of amps being drawn. On our older diesels, we have wheel slipping indicatiors which tells the engineer to drop a notch until the train is moving and amperage begins to drop. Diesels may also be equipped with multi-phase traction motors .. I don't know for sure. As I understand it, modern diesels are now computerized to handle all of those facits but may be over ridden by the engineer. (Is that correct Jerry?). Steam is a whole different animal. First of all, visualize this beast with all of it's raw power. Steam locomotives have 100% torque available even as it sits still so it's fairly touchy to start a heavy train without spinning the drivers. Steam locomotive engineers operate their locos by ' the feel in the seat of their pants'. Like the diesel, he'll select the direction he wants the train to move by setting the 'Johnson Bar'. Then open the throttle slightly. It takes a few seconds for the steam to move from the steam dome and fill the steam cylinders. You can see the steam issuing from the cylinder cocks and know pretty much when it's safe to release the brake(s). You can feel the locomotive sort of 'sit up' before it begins to move forward. Dump a little sand on the rails to enhance traction because often there is water dripping on the rails from something, (usually overflow from injectors) at any given time. As the train begins to move the engineer listens to the sound of the chauff and feels when the throttle can be advanced. The engineer will often keep his hand on the independent brake lever just in case he needs it to retard any spinning of the drivers while starting out on a grade, or with a heavy load. The only other major difference between a steamer and diesel that I can think of right now is steam engines 'store energy' for a time, depending upon how much steam pressure and how large the cylinders are, so the engineer much remain aware that the train will likely continue to move for a short time after the throttle is closed. I guess it all boils down to tractive effort and a balance of applied power, not unlike a race driver operates a dragster .. keep it right at the brink of losing traction, but don't. Hope this answers some part of your question. Copyright 2008 Jerry DeBene
It does sorta answer my question. Starting a train with a Steamer is like trying to get your car or any vehicle to start moving on ice. Just go easy and try to apply as much power w/o spinning. But if you break the adheasion you'll have a problem. The key is to take it real easy and apply power little by little as you begin to build up some momentem. On a traintape I have, the video crew taped part of the trip from the cab and we had commentaries from the engineer the whole time. I never realized that on wet rail you can suddenly start spinning w/o opening the throttle more. I always figured the engineer was trying to speed up when it began slipping but now I know that the locomotive will just do it on it's own if it comes to a slippery spot. I think we can all agree, steam requires more engineer skill than diesel. Copyright 2008 Jerry DeBene
Hey, how about a class on running F units? It must be more difficult than running something newer because it doesn't have an advanced wheel slip control system. An F unit class would be VERY interesting to me because CGWs primary power was F units. Copyright 2008 Jerry DeBene
Here's how I start a train here on Tehachapi... The main thing to consider is your trains HPT(horsepower per ton), the average is around 3.0 out of Bakersfield. The lower the HPT the more amperage you will need. With 3.0 HPT and several Dash 9's it will take around 1250 amps to start the train, or throttle 4. Now, on a train with no helper, I will release the train brakes. When the release gets to the rear of the train, I advance the throttle straight to run 4. As soon as the locomotives start to load, I release the engine brakes and apply sand, 9 out of 10 times this works just fine. Occasionally I'll have to go to run 5 to get it moving. Now a DP(Distributed Power) train is a little different. I will advance the throttle on the DP to run 5 and then release the train brakes. The DP will go from idle to run 5 in about 15 seconds(usually 3 sec. per notch) this is about the same time it takes for the release to get through the whole train. Then I advance the head end throttle to run 4, wait for the load, and release the engine brakes. If the train does not move within 5 to 6 seconds, I'll put the helper in run 6. Works everytime. As the train accelerates, I'll watch the amperage and as it drops 100 or so amps, I'll advance the throttle another notch. I'll keep doing this until I reach run 8 and with 3.0 HPT that usually gets me about 17-18 MPH. The heavier trains I'll be pretty gentle with as too much power at once means broken knuckles or drawbars, not to mention one mad Conductor......... Copyright 2008 Jerry DeBene
I figure that with 6 axle units anything around 5,000 amps total is really asking for trouble. 5,000 amps will shear perfectly good drawbars/knuckles without jerking. :thumbs_down: Thus with the above mentioned 1250 amps if you have 4 units that is a total of 5,000 amps and I'd be awfully nervous starting there.mg: Three units would be 3750 amps and no problem. :shade: Five units, ouch!:sad: Copyright 2008 Jerry DeBene
The 1250 amps is with the GE units. If it were all EMD units it would be more around 800 - 900 amps on the 2.3% grade here on Tehachapi. The GE units load up higher but limit the tractive effort until the train is moving. From a stop on level ground they load up at 300 amps in run 1 but take forever to start moving. They also drop there load if the wheels start slipping which can be a real pain in the but if they all do it at once. Management recently limited our head end power to 36 powered axles(Dash 9 is rated as 8 axles) which limits us to 4 dash 9's or 3 dash 9's and 2 SD40's. Copyright 2008 Jerry DeBene
If I remember correctly 12 axles will break any train they can't move. On the 7,000 HP ALP-44 electric engines we run each traction motor will drawn up to 2500 amps for a total of 10,000 amps and will hold that until the train breaks the sound barrier or we have to stop at a station. These motor loads don't drop off (like the freight haulers do) without a reduction in throttle. The newer 8,000 HP ALP-46 motors only read % of total traction effort but I suspect that they draw about the same as a ALP-44. Wheel slip for both locomotives is corrected by power reduction on the axle that is slipping. This really sucks since it can stall a train on a hill if there is no sand in the boxes and the rail is bad. With this much horsepower, wheel slip is also a problem on level dry rail so even under optimum conditions sand must be applied to the rail when accelerating between stations to keep schedule. Steve Copyright 2008 Jerry DeBene
Nah. I've sat stalled with two SD40-2s or C30-7s with the ammeter pegged at 1500 amps for a few seconds No problem. Those units are good for about 90,000 to 120,000 lbs of tractive effort at best before they will slip. That is around 200,000 lbs total for the two units (12 axles). Drawbars/knuckles are good for about 400,000 lbs before they break so you don't even come close. Even two AC units like SD70MACs are ok stalled. They can generate close to 180,000 lbs each or 360,000 lbs total for the two units' 12 axles. That won't break good (not previously cracked) drawbars or knuckles. We exceed 360,000 lbs total every trip going up the hills but with 3 units instead of two (120,000 lbs each). Now if you have 3 SD70MACs or C44ACs and try to get all you can get out of them while trying to start a stalled train, yes, now you will break it in two. But that is 18 axles and you are trying to apply 500,000 lbs of TE to a 400,000 lb drawbar. Copyright 2008 Jerry DeBene
Holding a stalled unit at a higher throttle notch for more than a few secons burns out older DC traction motors, right? The AC units can keep maximum amps going to the TM's without burning them, correct? Copyright 2008 Jerry DeBene
Bill, Like you I have only had the chance to run first and second generation loco's. I have run F units from time to time some years ago. I seemed to me that with the transission handle you would have the ability to start a stalled train in manual. Once the train was moving them you could put the handle back to automatic. Now you all have peaked my intrest so I will get out my engineer manual for the F units and see what it says. Shannon Copyright 2008 Jerry DeBene
