enabling even a small amount of momentum seems to make the behavior of a locomotive seem much more realistic, that it does actually weight a lot. You realize that it’s will take some practice to stop at a specific spot. I guess being able to control brakes would add to the realism.
With this in mind, how are cars coupled together?
it seems that you need to close(?) the throttle before reaching the car being coupled with, allowing momentum to push the two cars together. If you were to be able to stop a train at a specific spot, where would that spot be if the car being coupled to wasn’t there; how far past the coupler would that spot be?
Greg,I use a MRC Tech 6 and I found setting the momentum at (accelerate) CV3= 10 and (deceleration)CV4=12 works quite well for me…DC mode on the Tech 6 will be P3=10 and P4=12.
.I use scale switching speeds and I learn to shut the power off about 2 50’ car lengths from the coupling…This will give me a “kiss” coupling without moving the car(s).The same applies in spotting a car.
In short when using momentum speed and good eye judgment is the main factor.
Watching prototype switching at various yards, many and perhaps most crews come to a complete halt before coupling and then very slowly creep in for the joint. That is particularly true where a string of cars is headed by a parked locomotive, so it is not mobile, and a switcher is adding cars to the rear. Indeed often they “drop” the car and let it roll to the train, if circumstances permit, rather than have the switcher power the car into a string of parked cars headed by an immoble locomotive.
When I used to railfan at Milwaukee’s Butler Yard on the C&NW (now a UP facility) there was one brakeman who would instruct his engineer over the radio about how many car lengths they had to go by saying “Three to the crash. Two to the crash. One to the crash.”
Current railroad instructions are to stop short of the car, then creep up to it to make the joint. Back in the 60’s, I used to watch crews drift right up to the ‘joint’ and there was a 50/50 chance of a rough coupling(the ‘crash’ sound). Things are a lot more formal now. I have heard over the scanner while watching a DM&E local the ‘stop short’ , come ahead for the joint, ‘tug’ to make sure the joint is made, and finally ‘3 point’ protection while the conductor is lacing up the train lines. Most of the time with switching, the engineer is using the ‘independent’ engine brakes which can be quite fast acting. On the road, a local will use the independent when setting out or picking up a car, and once the air is laced up, and you have several cars - the train brakes are used(especially with cuts of 100 ton grain hoppers).
As far as ‘momentum’ in a throttle setting, I feel that getting the ‘start’ speed adjusted(CV2) is much more critical. Then adjust the momentum or BEMF if you have a rough starting engine.
Soundtraxx in their Tsunami and new non sound decoders have F11(function location can be changed) braking. Between accel/decel momentum and braking you can make them act much like the real deal.
Yep, it’s the same with CSX. When making a coupling, you have to make a “safety stop” within 1 to 5 car lengths from the car you’re coupling to. Then you must “stretch it” to make sure the coupling is good. Then of course “3 step” to get between the car and line the air. “3 steps” being 1) reverser in neutral, 2) independent brake applied and 3) generator field switch isolated.
I use Digitrax controllers that have a center-off/brake position. I set the switcher to go at a set speed around 6-8 scale MPH, then leave the throttle at that setting and just use the direction switch to run the engine. I have the momentum in the decoders set high enough that the engine slowly comes up to speed and “drifts” a ways after the direction switch is set to the center-off position. With a little practice, you can drift up to the car and just “kiss” the couplers together before the engine stops.
I seem to remember reading somewhere (or maybe seeing in a video) that a railroad (maybe Great Northern) back in the 1940’s-50’s had a rule that you had to stop short when switching passenger cars, to ensure a soft coupling that wouldn’t jar passengers (like when adding or removing a car from a train) but at that time I don’t think it required that be done with freight cars. However, in the past, when model engines didn’t run as smoothly at slow speeds as they do now, many model railroaders routinely did stop like that to ensure a soft coupling.
I don’t know the FRA rules, but knowing how things are these days in other areas, I expect it is a safety rule to not allow momentum coupling.
I have a DVD (Rio Grande Odyssey) which shows an power set of F’s (helpers) at Helper Utah summit. In the video, the F units have a caboose, they push and then back off the power. The caboose drifted away from the F units and there was a switchman who threw the switch just after the caboose passed, then F units went into the pocket (siding) behind the station and the caboose slowly drifted by momentum into the freight train waiting to continue down the mainline without the helper set. It was evident this crew had this down to a fine art, the caboose ever so gently ran into the end of the train and coupled with a light clunk.
The timing of throwing the switch was probably the real risky part here bacause if you were off one way or the other, you could throw the switch under wheels causeing a derailment.
that was called making a drop. sometimes called a dutch drop. it was one of those moves that management frowned upon if you tore something up or someone got hurt, but heartily approved of or at least looked the other way if it sped things up and it worked.
as for the gentle coupling, did you see anybody out on the platform at the handbrake controlling the caboose speed?
i tried a move like that with a box car one time. didn’t bother to check the handbrake first. spun the brake wheel after going by the switch and got about 18 inches of chain. scared the heck out of me, going too fast to get off so i got about a 3 mile wild, downhill ride. that track was not good for 50mph.
seemed like a good idea at the time to run the engine into the siding and let the car go down the main.
couldn’t let safety interfere with our early quit.
As long as all went well and the road foreman was peeking about…
On the PRR we went for a early quit and made a flying switch with a empty gon for a junk yard…
The other brakeman swung on board the gon and soon realized he was on the A end,he swings off and starts to swing back on the B end of the car and missed his timing.We started in hot foot pursuit of the wayward gon…The gon rolls on and rolls through the junk yard’s wooden fence and onto the street…Thankfully this happen in the wee hours of the morning and there wasn’t any vehicle traffic.
Try explaining that away in your accident investigation…We was given written reprimands.Today you would be fired.
if you didn’t have a few episodes of 5 days on paper, you were regarded as inexperienced and therefor unsuitable for promotion.
today, i hear they will fire a man for drinking!!! (although i never did)
closest i ever came to getting fired was when we discovered an asst. t/m weed weaseling by hiding in an empty gondola and we kicked a box car down on top of him real hard. he pretty much stayed in the office after that. (how many splinters will fit in one wanabe bosses behind?) all of them.
point of all this is that hard couplings had a rightful place in the overall scheme of things.
If only the engine or a couple of cars are moving, not much momentum (especially if the cars are empty). I’ve seen 2 gp38-2’s pull about 6 cars (prob empty) pretty fast from a local dealer (about 20 mph) and it accelerated to that in about 2 car lengths.
I turn off momentum while switching, making gradual throttle changes according to how many cars I do (or don’t) have coupled together. After the train is made, apply a momentum value (I have NCE) depending on how many ‘tons’ I have behind the loco and then hit the road. I generally slow early, and creep into a siding or up to a signal.
kind of interesting when you consider momentum and inertia in the real world. read some of the old icc accident reports and note the slow speeds at which fatalities occurred.
run two automobiles together at 10 mph and you get a couple of guys looking at their bumpers and cussing each other out.
run a couple of 5000 ton trains together, even, at low speed and see what happens. with all that weight moving, they just keep on coming until you have a giant pile of scrap metal.