Multiple locos and light loads

[numbat]

Hi All,

I'm currently travelling around with my demonstrator DH4 and DE6 back to back. Occasionally I will take a load that is reasonably light, and generally only have one of the locos running.

So I got to wondering if this is the most efficient way to do it? If I'm running the DH4 and the DE6 is not running, then I'm pulling an extra 125t of deadweight, which is about 1/4 of the DH4's effective capacity...

If I were running both engines, then I'd be pulling that load so much more easily, with much reduced throttle settings. I haven't done any real testing on this, but was wondering what others think?

Cheers,
Chris.

[ADFormer]

Actually IIRC the DE6 is more efficient than the DH4 in terms of maintenance costs I would say since you can summon the demos like you can the slug or handcart, I'd just use one of the demos if you only need one, if you need two, then summon another, but if you do want to do the DE6/DH4 combo I'd actually drive the DE6 as its cost per "work" is less than the DH4. I don't know the exact numbers, maybe someone can chime in with them, but there might be a point where it is better to use the DH4. I just know I've heard people say the DH4 costs more than the DE6

[numbat]

I must admit I've been leaning toward the DE6 as the main unit. Thanks for the response.

Cheers,
Chris.

[ling.speed]

Efficiency depends on what we are trying to max...

If its range, then low throttle settings (1-2 steps) are very efficient, and then since both engines have slip based drivetrains speed is very important on uphills*, which makes DH4 not great as a solo running machine with DE6 in and cargo in tow. Solo DE6 or both on would be best.

If its monetary efficiency, then running DH4 makes a little more sense, even thou its force cooled drivetrain is probably less efficient the engine being smaller should make it comparable in costs. Turning engine on from cold is wearing it down, so it would be better to eat some fuel inefficiency and pull over small slopes/level ground with just one engine. Which one thou, will depend on exact route and load.

DH4 and DE6 are the two locos i use the least so cant say definitely, but with how hilly most routes are i'd expect DE6 to be more efficient with most tasks.

ps: did a small test and can agree with ADFormer here, DE6 will be more efficient than DH4 when ran solo coupled together, but not by that much. If route limits speed or load is light enough DH4 could be similar with fuel consumption and smaller wear bill.
Running both at the same time seems to be just worse (unless you can use the extra power).



* - the more power we use the less fuel we burn, even through significant engine inefficiency. This applies to even DM since they too have fluid (slip) coupling despite having "Mechanical" transmission, only steamers can efficiently pull up at low speeds.