Greetings! I use two Proto 2000 GP 38-2 Locomotives (exactly the same models) together to pull longer consists. These were not purchased at the same time but also only about a year apart. The recent loco purchased runs slightly faster than the first one. Is there anything I can do to make their speeds exactly equal, and if not do you think running the two together will damage their gears? I use DC only and therefore can not take advantage of DCC consisting. Thanks for any advice.
Here’s a quick test to see if two locomotives can successfully doublehead. Put the faster one on the track with half the cars you want to pull. Put the slower loco, and the rest of the cars, a short way back. Then run both trains off a single throttle. If the front loco pulls away, move a car from the rear train to the front train and try again. Eventually, you will either have two trains running at the same speed or the faster locomotive will have the whole train and the slower loco can go looking for another assignment.
Of course, you might have a grade steep enough (or a train heavy enough) that the faster loco will slip its drivers and stall. In that case, the second loco will be needed to pick up the slack.
Operating at prototypical speed (aka slow) with part throttle, two radically mismatched locos can successfully move a train without fighting each other. I routinely assign diesel-hydraulic helpers to steam powered trains for the 2.5% grade between Harukawa and Tomikawa. Since the helper is actually needed, the mismatch in performance isn’t a problem.
Chuck (Modeling Central Japan in September, 1964 - analog DC, MZL sustem)
[#welcome] aboard, Doug. And welcome to the DC double-heading problem. Actually, it’s not that bad. Chuck (as usual) had some very good thoughts.
I run steam more than I do diesel, but there are times that I have to double-head because of a couple of stiff grades on my MR. What I do–and this should apply to multiple-unit diesels as well, I would think–is to put the slightly faster steam locomotive (helper) in front, with the slightly slower (road) locomotive following. With a load of freight cars, it only takes a few feet for the locomotives to get into a relatively smooth-running ‘tandem’ operation. And I don’t have any gear-mesh problems at all.
I just acquired an Alco RS-3 that I plan on ‘sandwiching’ between my F-3 units, a-la-Rio Grande 1st Genration diesel practice, and I don’t forsee any problems. Test runs have shown that they’re relatively compatable.
So MU-ing can be done on DC as well as DCC–I’ve been doing it for years.
Hello Chuck. Thank you for taking the time to reply. This sounds like a very useful test. I am looking forward to trying it. I think I will print out your reply to keep for future reference.
Tom thank you for your suggestions. Good luck with your Alco. I to have a few grades I would like to experiment with using helpers and am eager to try your suggestions.
By the way what a useful tool this forum is. I never thought I would get such useful suggestions so fast. Thanks again everybody! [swg]
I do things a little differently than tomikawaTT. My procedure is designed to put all the locomotives on the head end of a train.
At a specified throttle setting determine the speeds of a certain number of locomotives–for this purpose we will use three. Set the slowest of these three locomotives aside, set the second fastest locomotive on the track ahead of the fastest locomotive–leave a separation of, say, one foot between the two. Hook a train up to the fastest locomotive and go to the specified throttle setting and observe what happens; keep adding–or removing cars in the event that the fastest locomotive is faster then the second fastest locomotive–until your second fastest locomotive is barely running faster than your originally fastest locomotive. When this event occurs you add one more car and connect the two locomotives together creating, in effect, a single locomotive.
Once you have done this you can now execute the same procedure with your third fastest locomotive, the one set aside at the beginning of our procedure. Sooner or later the load on our train–the one with two locomotives–will increase to the point that all three locomotives are running at the same speed.
This procedure will work with any number of locomotives–the most I have seen was a five unit lashup of diesels from various manufactures–but it is essential that you remember that specified throttle setting!
I first observed this procedure on a club layout in Massachusetts in about 1965 and I observed it again on the Frankfort Model Railroad Club in Germany in about 1972.
And lest I forget, glad to have you as a member of the forum.
You can add resistors to the faster engine to slow it down. If there is an extreme difference, you can remove the lightboard from the slow engine and hardwire it back together. Because the lightboard has a ‘constant lighting’ circuit, it eats up the first few volts of power, so removing speeds the engine up.
This thread over the years has received lots of play. There is always many pros and cons and I don’t mean to belittle any advise from other members as I know they are giving information based on their experience, and their best wishes for you…
But for me, I have close to 40 Locomotives, mainly Diesel, and thats what I am speaking of now. And over the years I have had very few lash up problems. I mainly run two or three units per mainline train and I have found that my Proto, Bachmann and Atlas will all perform well together. Do not throw an Athern in the mix. Keep Athern with Athern, and you should not have any signifigant problem.
I know this seems very simplified, but it works for me. My mainline trains are usually in the 25 to 30 car length.
When I was in DC I found I could usually run Atlas engines together pretty well, but other makers like Life-Like and Athearn could be very different from one engine to another. (That’s why “dummy” engines were once so popular, so you could “run” two engines without the hassle of trying to get their speeds matched.)
Thank you for your useful info re MU consisting. Sorry I am so late in getting around to acknowledging your help. The specified throttle setting is something I didn’t think of.