Pulling capacity of pickup with railroad trucks

[brianle]

The railroad often uses pickup trucks equipped with railroad trucks (wheels) to travel along railroad tracks. I would like to know how much weight such a pickup could pull on the track. Would it be possible to pull a 100 ton railroad car on a "level" track with a pickup with a towing capacity of 12000 lbs.? I would imagine the coefficient of friction for rubber on steel would be less than rubber on macadam. Railroads drop sand on the tracks in front of the locomotive wheels to give them more traction. Could this method be used to increase the traction of the rubber on the steel rails?

 

[carnage1]

Why do I suddenly have visions of a truck full of rednecks swiping box cars for joy rides?
I am not sure how to approach this question, If the tires don't get enough grip then getting started will be difficult, but if grip is not an issue I have to wonder if you could snap a drive line or something like that.

Luck is a difficult thing to verify and therefore should be tested often. - Me

 

[dvd]

I think the key to this is that you have to start and stop the load. If you apply a force that just overcomes the frictional resistance of the wheel bearings on the railcar, then the railcar will start to move. The issue will be how long it takes to accelerate to a reasonable speed. Since pneumatic truck tires distribute the load over a larger area, my opinion is that there wouldn't be much gain from sanding the track, at least when it is dry.

 

[MintJulep]

It takes remarkably little force to get a rail car moving provided that the wheels and bearings are in good condition.

A pick-up highrail could easily get a single car moving.

 

[brianle]

Carnage1 - your comment was hilarious. Since I'm just looking for an alternative way to move one car at at time in our plants train yard if our locomotive is out of service, speed won't be a big issue. MintJulep - is there anyone you know that uses a pickup for this type of situation?

 

[MintJulep]

I've never seen a pick-up properly outfitted for moving cars around. I almost bought a Unimog that was equipped with couplers, compressor and brake controller once.

There are various purpose-built switchers such as the railmobile.

Manufacturers move cars around with fork lifts.

 

[rmw]

I don't think it would take much to get the rail car rolling based on my memory watching a string of rail cars roll off into the distance when I released the brakes on them when I was a kid visiting my grandparents. I lived in that town as an adult and many times I went by that section of track I still marveled that there was any slope at all.
You couldn't see it with the naked eye.

The pick up could do it. You might have to put some weight in the bed, but hey, I do that to my personal pick up truck just to make it safe in the winter. Put enough weight on the drivers and it will pull it.

However, if you are going to do this with regularity, be careful how you spec out your pick up truck. Good low speed rear end(s) and extra heavy duty auto trans (this would be heck on clutches) with a REAL good external cooler. Most of what you will be doing will be with the transmission in a high slip stage.

Be sure to PM the transmission regularly too. That kind of service will cook the trans fluid rapidly.

I once pulled a large bus-less weight; about 15 tons several miles across town to a shop with a pick up truck. The terrain was relatively flat but pulling the bridge over the river was heck. The truck did a good job. We rarely got over 20-30 mph. (The bus would run so as to air up the brakes but had a drive line problem so that it wouldn't pull itself.) I always wondered how much I aged the tranny in my truck that evening.

rmw

 

[EdDanzer]

Drawbar pull is the weight over the driven tire times (*) the coefficient of friction. The coefficient of friction between steel and rubber could be between .2 and .85 depending on if it is wet or dry. If you measure the pull required to move the car with the locomotive then you would be able to determine if the pickup could do the job.

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com

 

[GregLocock]

Hills would be the killer, and braking.

Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[MiketheEngineer]

I agree - I would worry MORE about stopping it than getting it going!!

Check your brakes...

 

[MintJulep]

In theory, the forces involved with stopping are no different than those involved in going.

Reality may be a bit different if it is a half-filled tank car.

 

[btrueblood]

Or use one of these:

http://www.mcmaster.com

- item # 2221T8 $199.74

 

[swall]

My first employer used to make purpose built vehicles for moving aircraft away from the gate. Some were sold equipped with rr couplers.

 

[carnage1]

Could you build a little brake controller to couple to a single car so that you only have to get it going and can use its brakes to stop?
I think the rubber to clean steel coefficient of friction would be much greater than for rubber to sand to steel. I don't think you have enough pressure under the tires to turn the sand into something grippy, I think it would act like lots of little ball bearings.
Lastly do you have a granny low gear? If so you might not have to much trouble.

Luck is a difficult thing to verify and therefore should be tested often. - Me

 

[unclesyd]

Just talked to a friend who works for CSX while riding the rails in pickup. His pickup is special 4 wheel drive, heavy duty transmissions, etc. The tires on his truck are special and you definately don't want sand under the tire. Road crossings can give him trouble if there is sand on the rail and he is pulling a load.

You might also look at renting a rail car mover or shunter. We rented a mover numerous times when our Trackmobiles went down.

 

[griffengm]

We used to move 100 ton fertilizer cars using a 3/4T Chevy 4x4 5-speed with hi-lo tranny. The trick to stopping was the second man at the brake wheel. Not recommending this, just saying its' been done.

Griffy

 

[brianle]

Thanks to all of you for your input.

 

[DAVIDSTECKER]

When we spec out a capstan to pull rail cars we use a general rule that it takes 10 pounds of running pull for every 1,000 puonds of rail car on flat, straight, solid track.
15 pounds per 1,000 for starting.