Western Railroad Discussion > Light Engine Moves (Question)

Why are light engines required to move at restricted speed? I pick that up from reading various threads and have noted it when looking at old employee system timetables. Thanks.

Posted from iPhone

There is no speed restriction that I know of unless a specific rule / operating condition requires it, such as flagging past a red signal or non-ABS yard limits.



Edited 1 time(s). Last edit at 04/08/19 10:37 by Railbaron.

Yeah, need more information. 

johnambrose Wrote:
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> Why are light engines required to move at
> restricted speed? I pick that up from reading
> various threads and have noted it when looking at
> old employee system timetables. Thanks.

Generally speaking because a light engine, whether steam or diesel, doesn't have very good braking power without a train. But, as others have posted, a bit more information would be helpful.

HotWater Wrote:
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> Generally speaking because a light engine, whether
> steam or diesel, doesn't have very good braking
> power without a train. But, as others have posted,
> a bit more information would be helpful.

That what I expect him to be asking about - assuming that he doesn't mean Restricted Speed but rather the move has a speed restriction.

TAW

In my corner of the railroad light engine moves with 1 unit are restricted to 30MPH, 2 or more 50MPH.

Posted from iPhone

Tom is right, the move won't be "Restricted Speed," but rather there is a restriction in the top speed allowed. Usually this is due to not enough axles to properly shunt the signal system.

Insulated joints were quite often staggered several feet, and  one or two 4-axle units can completely disappear from the signal system for a second at higher speeds.

Please note the post from last week here about "Strange move on Auto Train?"  An engine had to go some distance on the main track for service, and by taking an empty auto rack with him, he avoided the axle and length restrictions, and was able to go Max Authorized.
G

On BNSF, AMTRAK and U.P. lite engine moves are restricted to 45mph out west. And yes it's due to braking. A train with rolling stocks have shorter braking distance then a bunch of motors.

Posted from Android

Unless changed since 2005, on CSXT was 30 for a single light unit. We use to grab a car or two to get around the rule.

Steve Panzik

I can only speak of the UP as that’s the railroad I’m very familiar with as far as rules go. Light power moves are permitted 70 mph. However, there are restrictions. If you are not able to control speed with dynamic brakes, as in the locomotive is not equipped with them or they are inoperative, then you are restricted to 45 mph. Now, grade crossing rules state that if you have 12 or fewer axles, you must approach all crossings equipped with active warning devices (lights and/or gates) prepared to stop unless it can be seen that warning devices are operating normally. So, you may be able to go 70 but you must approach such crossings prepared to stop. 

The-late-EMD Wrote:
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> On BNSF, AMTRAK and U.P. lite engine moves are
> restricted to 45mph out west. And yes it's due to
> braking. A train with rolling stocks have shorter
> braking distance then a bunch of motors.

I was hoping for more information from the OP but the above 45 mph limit is probably on a subdivision basis. Light engine consists are permitted 70 mph on BNSF with exceptions, as IMRL mentioned above. The current pertinent rules from the BNSF Special Instructions are as follows:

1. Speeds

All trains consisting entirely of passenger equipment as well as locomotives without cars (light engines) will be considered passenger trains and may operate at passenger speeds where provided. This includes Amtrak, commuter trains, business cars and passenger equipment modified to serve as track inspection, track geometry or similar test cars. Refer to 1(B) regarding maximum authorized speed of engines (locomotives).

1(B). Maximum Speed of Passenger Trains/Engines

Amtrak 90*
Metrolink 90*
Metra 79*
Sounder (Sound Transit) 79*
Northstar 79*
All other classes 70*

Exception:
When the controlling locomotive is a car body type or has a desktop control stand and is being operated long hood forward, maximum speed is 45 MPH.
* Engine without cars must not exceed 70 MPH.

11. Shunting the Track

Single Unit Light Engine
When a train sets out all cars enroute and becomes a single unit light engine within CTC, manual interlocking, or ABS territory, the train dispatcher/control operator must be notified.

Movements Consisting of Less Than 12 Axles
Train, engine and other such movements consisting of less than 12 axles must approach road crossings at grade equipped with automatic crossing warning devices prepared to stop until it is determined that the warning devices are operating properly.

Most of the above replies are quite informative;  thank you.

I had remembered from years [ I mean YEARS ] ago that single units were only permitted to travel at low speeds because of the risk of a single point of failure in the braking system -- typically, a broken BC line that would hence keep all the cylinders from applying.   This is one reason that in those instances were it was desired to enable a single unit, typically an RDC or electric MU car, to travel a track speeds the "Single Car Emergency" brake package was added to give a degree of redundancy.  It is interesting that dynamics are now considered to be a valid secondary braking system -- hopefully the engineer in question does a running brake test at the first opportunity......

Best, SZ