weighting plastic locomotives

[Anonymous]

Rule of thumb question. Is there some usual amount or minimum/maximum to weight the newer plastic steam HO locomotives in an effort to increase traction? At what point is the motor in danger of over stress? Any "guesses"/views/reference texts?

Randy

[Anonymous]

In part I can share with you my weight requirements. Steam or diesel, 16-17oz or better.

I always demand to know the weight in advance. Anything less on my layout could cause wheel slippage.

I won't buy the Athearn Genesis because their steamers come in between 12 3/4 to 13 1/4, too light.

On the other hand the Atlas Dash 8-32B just qualifies.

[Anonymous]

Generally you can increase the weight of the loco as long as there is space but the loco still has to be able to slip it's drivers.

To test this hold on to the tender and turn up the throttle. If the wheels skid you are fine but if they stall then you could cause mmotor damage due to overheating.

You can get various lead aloys that have very low melting temeratures. I think there is one from Hobbytown of Boston called Bearmetal that melts at 75C. This means that you can pour it into a plastic boiler without melting it and get a higher weight than with lead shot or whatever.

Neil

[Anonymous]

Unfortunately I bought four Athern HO 2-8-2's and found even double heading they won't pull more than 14-15 cars up a 2.5% grade. No way to add weifght either. I will but NO more Athern locos. They should have caught this problem.

[Anonymous]

A 2.5% grade is extemely steep in real (and model) railroad terms. Add any curve to that grade, and it will be really difficult for any loco, including Atherns, to get up the grade.

Andrew

[Anonymous]

QUOTE: Originally posted by mopac55

Unfortunately I bought four Athern HO 2-8-2's and found even double heading they won't pull more than 14-15 cars up a 2.5% grade. No way to add weifght either. I will but NO more Athern locos. They should have caught this problem.

How about placing your second loco at the back end ?

Also, I used a P1K- F3 powered B unit under the shell of an athearn reefer. Almost a Perfect fit and I cut it in half way back.

[Anonymous]

Thanks for the insights. Very helpful to me in locomotive selection.

Randy

[tomwatkins]

I agree that 2.5% is a steep grade and that as long as you can slip the drivers, more weight is better. 16-17 oz. would be outstanding, but it can be tough to do. However, there is one more thing that needs to be mentioned. It's important that the weight of the locomotive be balanced front to rear over the drivers.
The Athearn 2-8-2 weighs approx. 12.6 oz. out of the box. The Spectrum 2-8-0 also weighs approx. 12.6 oz. out of the box but it's a lot smaller locomotive. The center of balance on the 2-8-2 is between the 3rd and 4th driver making the locomotive very tail heavy. The 2-8-0 balances nicely between the 2nd and 3rd
driver.
My ruling grade is a curving 2.5% which I'll admit is a tough steep grade. It approximates a much steeper grade, complete with curves on my prototype.
The Spectrum 2-8-0's without any additional weight will pull 8 40' cars and a caboose up it without helpers. This is what the prototype's 2-8-0's were rated at on that grade.
The Athearn 2-8-2's have an additional 2 oz. of weight added, all of it forward of the 3rd. driver. This helps but not enough to move the center of balance as far forward as it should be. They will only pull 8 40' cars plus a caboose up that grade. So far I've not figured out how to get more weight into the front of the 2-8-2's and that is what it's going to take to get them to perform properly on grades. I should mention that that they pull fine on flat level track and the low speed performance is great. The next thing to try is to saw off the front of the weight and fill the boiler with low temp melting lead. I've got the lead but just haven't gotten started on it yet.

Tom Watkins