Moving "dead" locomotives

[NP Red]

It seems to be common practice to move locomotives in a consist -off line. It seems to me that that would be hard on the traction motors/gears. Would there not be some "drag" because you would be spinning the traction motors several revolutions for each wheel rotation? Also I would think that a locomotive would not "run away" on a slight grade as fast as a boxcar with the brakes released. Is towing a locomotive the equivalent of pulling several loaded boxcars?

[wjstix]

It shouldn't do any harm, any more than putting your car in neutral and pushing it would. I don't think it would be any different than hauling a car, except as you note for the weight.

In steam days if they had to move a steam engine a long ways they would remove some of the connecting rods.

I would think an engine would be as likely to roll downgrade as a freight car, maybe more so due to the extra weight.

[NP Red]

It shouldn't do any harm, any more than putting your car in neutral and pushing it would.

Maybe so but the locomotive isn't in neutral, so to speak, the gears are engauged and spinning the rotors.

[WSOR 3801]

Towing diesels doesn't hurt anything.  There may be slightly more drag, turning the traction motors as well, but it is negligable.  Most 4-axle engines weigh around 263,000 lbs or so, same as a loaded 100-ton capacity car, not really all that heavy.  6-axles can weigh 360,000-432,000 lbs, so there is a little more weight to  knock you around.  Usually when an engine is towed shut down, the air hoses are all made up, so it does help with the braking at low speeds (under 10 mph).  Engines without alignment control couplers have special handling requirements.  Usually they are cut in between the bigger road power, to avoid jacknifing.

 

[wisandsouthernkid]

hey 3801 PM sent!

[trainfan1221]

I recall stories of taking locos that weren't helping off line and just pulling them along.  I remember one where the dead "B" unit was referred to as a "heavy boxcar".

[wabash1]

 Engines without alignment control couplers have special handling requirements.  Usually they are cut in between the bigger road power, to avoid jacknifing.

 

exsplaine this to me as i have never heard this. cut in between bigger units??? What if they are fra dead ?????

 

[BigJim]

exsplaine this to me as i have never heard this. cut in between bigger units??? What if they are fra dead ?????

Read your NS-1. Tells you all about it. And it doesn't matter if it is FRA dead, as long as the unit is dead.

[Lyon_Wonder]

I can think of 2 reasons why an inoperable locomotive would be towed; burned out traction motors or prime mover, or hauling a loco to a museum.  I've seen a picture of a UP DDA40X hauling EMD's original FTA/FTB pair, which I think was in the early 90s.  I don't think those FTs were operable either.  IIRC, the last former-ATSF SDF40 on BNSF's roster repainted into Maersk colors wasn't running when BNSF took it all they way out to California either.

[wabash1]

I can think of 2 reasons why an inoperable locomotive would be towed; burned out traction motors or prime mover, or hauling a loco to a museum.  I've seen a picture of a UP DDA40X hauling EMD's original FTA/FTB pair, which I think was in the early 90s.  I don't think those FTs were operable either.  IIRC, the last former-ATSF SDF40 on BNSF's roster repainted into Maersk colors wasn't running when BNSF took it all they way out to California either.

there is more than those minor reasons but i was trying toget him to say why he was doing these steps on that particular engine. but it dont matter and im dropping the subject.

[BaltACD]

  Engines without alignment control couplers have special handling requirements.  Usually they are cut in between the bigger road power, to avoid jacknifing.

 

On my road the special handling is the train is limited in the amount of trailing tonage account of having an engine without alignment control in the engine consist...no matter the loaction of the non-alignment control engine within the the engine consist.

[WSOR 3801]

Usually, only switchers are not equipped with alignment control couplers.

On the CP, usually a switcher is in between 2 road units.  The couplers on the road units won't swing as far, so the jacknifing shouldn't occur.  On my road, we can't have more than 2 switchers in any consist.  No tonnage restrictions at this time.

[R. T. POTEET]

I don't remember the author's name but he was a retired Mopac engineer and back in the 1970s-1980s he reminisced about his railroading experiences in numerous artilcles published by the NMRA Bulletin. In one he told of a train "deadheading" an SW switcher in the consist that was supposed to have a 30 MPH speed restriction; somehow or another the locomotive crew failed to get the word and when the switcher was dropped at the North Little Rock shops a transmission change was in order.

[rrboomer]

The most common reason for a dead in tow speed restriction on a SW type switcher was due to friction bearings and/or flat spots.  On the Soo for example, it was 25 mph for friction. 

There is no "Transmission" on a diesel electric locomotive.  If the freight train went fast enough they could have unwound a traction motor on the SW (unlikely), or knocked the shims out of place on an axle brass and scoured a journal.

[dehusman]

Actually non-alignment control couplers were fairly common on early diesels.  Pretty much anything past a GP35 or GP40 would have alignment control couplers.

Dave H.