I’m building a large HO layout in my basement…much to my wife’s dismay I’ve pretty much taken over the whole basement with it. It contains plenty of gentle curves and realistic grades of up to 2%.
On the new layout I’ve been running longer trains…up to 50 cars in length…and have noticed that they take alot more skill to operate than the little five or ten car trains on my earlier layouts did.
One thing I’ve discovered is that “taking a run” at a grade almost always leads to derailment. On the other hand, a steady speed approaching the grade always works…the trick is to maintain that steady clip on the approach and on the ascent/descent. To me that seemed counter intuitive because as a (car/truck) driver I always take a run at the hill to avoid coming to a crawl at the top. But then I realized that cars and trucks don’t have slack, and I figured it would be best to run my trains to minimize changes in slack as they go around the layout…and sure enough a steady speed regardless of grade leads to fewer derailments. The speed itself also seem to matter…too slow and I have problems on the downhill as cars take in slack and are held back by the locomotives… and on curves that pushing force has a lateral component that seems to encourage derailment. Too fast and I’ve got the opposite problem…the train basically pulls itself apart.
Is that bascially how it works in “real life” or do trains take a run at grades? Also, on curves is it important to accelerate through curves?
I’m not a pro, but if you’ll read the two freight-train oriented chapters in John McPhee’s nonfiction book Uncommon Carriers, you’ll get a feel for how critical speed management is even on gently undulating Great Plains tracks w
It’s been a while since I’ve touched a model train, but they always seem to have too much slack in them. Your cars probably don’t weigh enough, either, so you’re getting some of the string-line derailments that occasionally happen to the prototypes on curves, too.
Nothing like being slammed into a locomotive windshield by slack run-in on a downgrade. Most anyone with a modicum of training can run a locomotive but proper train handling, of which slack management is a big part, comes only with experience.
Our trains are short - typically three cars, but as many as 6 during peak season, but our “cargo” is a little pickier than the usual - we’re hauling people, and over a profile that is anything but flat.
I don’t spend any time in the seat although I do get some cab time, but as I learn the line I gain a greater appreciation for the engineer’s ability to handle the train smoothly. Judicious use of throttle and brakes are critical. Even a small grade can be a challenge when starting and stopping.
NO!!! brakes are for stopping not controlling slack, slack is controlled by the terain and the speed of the engine which is controlled by the engineer. you controll slack by knowing the teritory, knowing what the rear is doing and running from the rear … and feeling it in your seat.if it looks simple then the engineer got his act together.making your ride safe and smooth.
wabash 1: Can you elaborate on this please? I’ve seen a local ethanol / grain train at a rural crossing that was really revving up on the lead end, approaching another hill, while the back end was still coming down a hill, and running in the slack. It looked to me, like a lot of work, to control the slack action on a hilly line.
Keep in mind there are usually three (Or was it four?) collisions that happen in a motor vehicle. The vehicle against something that acts upon it… like a wall. The person inside the vehicle against the interior or restraint system, the cargo against the vehicle and probably the person as well. The 4th possibility applies to 18 wheelers, trailer against cab with it’s own load. The 5th collision will sometimes be the driver thrown out to impact the ground, pole or whatever.
Rollovers are the worst. The driver gets to impact the cab interior in a multipule cartwheel breaking a bone or three on each hit until the entire object stops.
It will slam you back until it runs out of coupler slack and then the resulting JERK slams you forward. Slack works both ways when it runs into something that needs moving. I recall hearing stories of caboose crews being tossed out.
Ive had loose 5th wheels that slammed but never experienced bad slack on a train. Most of the touring railroads under steam Ive ridden were careful to ease into the inertia and not make slack run in or out. Maybe a little bit when stopping, cannot really avoid that.
Grades on model trains, I overpower my consist by weighted motive power and just march uphill at a low speed without wheelslip. Going down? Well, I just gather it in against the tender and hopefully the speed I selected will not cause the engine to be run off the track.
6 to 10 pounds of train on those Kadee couplers are good enough. They just dont fail like the plastic ones do. The plastics always fail on the first bad s
Keep in mind there are usually three (Or was it four?) collisions that happen in a motor vehicle. The vehicle against something that acts upon it… like a wall. The person inside the vehicle against the interior or restraint system, the cargo against the vehicle and probably the person as well. The 4th possibility applies to 18 wheelers, trailer against cab with it’s own load. The 5th collision will sometimes be the driver thrown out to impact the ground, pole or whatever.
Rollovers are the worst. The driver gets to impact the cab interior in a multipule cartwheel breaking a bone or three on each hit until the entire object stops.
It will slam you back until it runs out of coupler slack and then the resulting JERK slams you forward. Slack works both ways when it runs into something that needs moving. I recall hearing stories of caboose crews being tossed out.
Ive had loose 5th wheels that slammed but never experienced bad slack on a train. Most of the touring railroads under steam Ive ridden were careful to ease into the inertia and not make slack run in or out. Maybe a little bit when stopping, cannot really avoid that.
Grades on model trains, I overpower my consist by weighted motive power and just march uphill at a low speed without wheelslip. Going down? Well, I just gather it in against the tender and hopefully the speed I selected will not cause the engine to be run off the track.
6 to 10 pounds of train on those Kadee couplers are good enough. They just dont fail like the plastic ones do. The plastics
Hi everyone I am a locomotive engineer and Wabash is right, I have to know the route I operate on like the back of my hand. It is nothing for me on a 130 car coal train to have the head 1/3 of the train going downhill, the next 1/3 comeing uphill and the rear 1/3 going downhill it is a matter of using the throttle to controll slack, durring the trip if I can keep the conductor on the engine it is a good trip. I only use the trains air brakes along with the dynamic brakes to control train speed on a long downhill grade, as soon as the head of the train nears the bottom of the hill I realese the brakes ease back on the dynamic and start adding power to the engines to streach the train out. I do not like to have my train comeing appart (i.e.) the conductor has to handle a 85pound knuckle.
Most likely the engineer was trying to “run away” from his train’s rear end (keeping the slack stretched) as it came down the hill (in addition to running at the hill). Or else he was coming off of dynamic braking and going to power.
I never heard of someone being tossed out, but I have heard of guys in the caboose getting broken ribs and limbs from slack action. I’ve had a slack run-in give me an instant 15mph boost in speed, as well as a slack run-out almost bringing me to a stop.
Running freight train became so much easier (at least as far as slack management goes) when the cabeese were removed. One still must control the slack in order to protect the lading, but mostly slack control is used to keep the train intact.
Thank you for the memory jog on the speed decel or boost. I recall the milk tanker had no baffles and when one finished the stop at the traffic light all that liquid is gathered up at the front. Guess what? It now slams to the back of the tank some 30 feet away literally trying to drag the truck brakes and all backwards a few feet. That is probably as close as I want to deal with such forces.
Thank you for the clarification of the caboose crew. I wonder if the Engineer is made responsible for crew injuries due to slack? Did such a thing exist in the steam days? Certainly the boom falls on that engineer if he burns the rails too much with wheelslip for example.
Yes, absolutely, unless the slack action was from a source other than train-handling, such as air hose separation or a broken knuckle or drawbar (causing air loss), although a broken knuckle and/or drawbar brings along their own set of questions…
Can’t say from experience regarding steam locomotives, but I would guess the situation would be similar.
Thank you for all the info. I still am not clear about the electronic braking. Can it be used kinda like the stability control on car wheels? Part of a train would be braking where another part is not, all in varying degrees, to reduce the potentially destructive forces in play; making it easier for the engineer to control the train?
Nope!
Either all of the brakes are applying, are on, or releasing. What the electronic air brakes have over regular air brakes is that they 1) apply uniformly at the same time throughout the train and 2) if too much air is applied, some can be released without releasing the brakes on the entire train. You can’t apply the air brake to a certain portion of the train.
Air Brakes are big dumb brutes who get nothing passed on to the shoes, a little bit of reduction passed on OR ALL OF IT BIG HOLE.
The Airbrake system on a train cannot “Pick” one axle to put a brake on. If it could, it is not agile enough to keep up. Even if it could, the engine will be exhausted trying to feed all of those little demanding air brakes working individually. No. Airbrakes are a all for one and one for all within the limits of the piping.
Electronic braking on cars can be put onto trains, trucks or anything else but I consider them rather a bit of a …**searches for word… blashemy. Sometimes you just gotta jog a wheel or a pair loose to get your vehicle where you want it to. You can load down a car with all the fancy frankenbraking driven by the very best in nanny controls but it cannot ever make up for very bad drivers.
Now, ABS (Anti Locking Braking) will have potential for saving flat spots on steel wheels if you could build one stout and big enough to withstand railroad duty with zero maintaince. Ive used this on big trucks over the years and let’s just say there are at least a dozen lives including my own saved time after time by this wonderful system.
Having thought on this slack issue, I wonder if the UK has snuck one over on us enjoying thier buffers in addition to thier couplers.