Adding Weights to Locos

Discussion in 'Getting Started' started by RobertInOntario, Jun 1, 2007.

  1. RobertInOntario

    RobertInOntario Active Member

    I have a Mehano/IHC (Loblaws/Presidents Choice) steam loco. It's a CN 2-8-2. It runs well but struggles when it hauls a long load, i.e. over 8 or so cars.

    Last night, as an experiment, I "stuffed" two half ounce weights into its cab and it hauls long trains much better!

    Obviously, it doesn't take much weight to make a difference. Ideally, I want to find a better place to mount these weights! (but this IHC loco seems a little complicated to take apart).

    How much weight do you recommend to add to locos, in order to get better traction? Also, I once read that adding extra weight can strain the motor, putting extra wear & tear on it -- is this true? I'm willing to 'risk' it with this loco -- it can now haul a nice long freight train.

  2. doctorwayne

    doctorwayne Active Member

    Rob, unless your loco is a real el cheapo, with a pancake motor, there is usually not enough room in the boiler shell to install the amount of weight that the loco could handle. In general, you can continue to add weight as long as the loco is able to slip its wheels when the weight of its train prevents its forward movement. To check for wheelslip, add one car behind the tender, and while manually holding the car (not the loco) apply power. As long as the wheels slip (spin), the loco can handle additional weight. If you have a situation where the wheels will not slip, the motor will quickly become overheated, resulting in failure of the insulation on the windings and destruction of the motor. In my opinion, for this reason it is not a good idea to add weight to locos with traction tires. In preliminary testing to determine if it would be worthwhile to add weight to my Athearn Mikados, I applied a "saddle" of folded sheet lead, draping it over the exterior of the boiler, then tested for wheel slip using the method outlined above: the wheels still slipped readily with a 22 oz. "saddle" in place.
    Equally as important as adding weight is the need to balance the weight around the centre-point of the driver wheelbase. Make a simple balance using a rigid piece of wood or metal with a pencil as the pivot point. When you get the wood or metal piece to balance, mark the balance point for easy reference. Set your loco on a scale ruler to measure its driver wheelbase - this is the distance between the points where the front and rear drivers touch the ruler. The mid-point of this length is the point that you should position at the mid-point of the balance. (The balance test is done with the loco only - remove the tender) If the cab end of the loco bottoms out on the balance, you need to add weight to the front of the loco, until the loco sits level on the balance. An ounce added near the front of the loco will make more difference than an ounce added just ahead of the centrepoint. Once the loco has been balanced, you can continue adding weight equally to both the front and rear sides of the pivot-point.
    If you want a few ideas for adding weight, check here:

    Boosted output from an amplified Mike...

    I add weight to all of my locos.
    These modified Athearn switchers are 13 oz. each

    Model Power FPA-4 - 23.25 oz.

    Model Power FPB-4 - 26.25 oz.

    And these modified Athearn U-boats, at 33.5 oz. (There's no room left in these for more weight, but they could easily handle a couple more pounds)

    And by adding weight to this Proto2000 0-8-0, I managed to double the amount of cars that it can pull.

  3. RobertInOntario

    RobertInOntario Active Member

    Thanks, Wayne -- great info -- I just read this and am going to reread it again later!

    Yes, I suspected that my loco was now unevenly weighted because of the extra weight being in the cab. When it goes through one curved switch, for example, its front wheels derail (I suspect b/c the extra weight in the back is causing the front to ride up).

    I'll see if I can get the weight evenly distributed inside and possibly add even more. I'll do this, of course, after I've done the wheel spinning test that you describe.

    Impressive pics and work BTW!

    Take care,
  4. 0-4-0 Steamer

    0-4-0 Steamer New Member

  5. MasonJar

    MasonJar It's not rocket surgery

    I have an old Mehano/IHC pacific, and improvements were made not so much by adding lots of extra weight, but better balancing the weight over the drivers. While there is not a lot of room in there, you can add weight into (some) sand or steam domes, etc. But the best advice is to follow docotorwayne's advice...! ;) :D

  6. RobertInOntario

    RobertInOntario Active Member

    Well, I tried this again tonight with one of my small British locos, an 0-6-0 tank engine that I'd recently kitbashed. I temporarily stuffed about 1.5 ounces of weights into its cab and it was 'suddenly' able to able twice the amount of coaches as previously.

    Of course, as per the above, I do plan to find ways of better installing the weights but for now it's great to see it hauling four coaches instead of just two. And it's running nice and smoothly as well.

    This is great to find out but I'm a bit late or slow to learn this!


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