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Correct Weight Distribution to Increase Locomotive Pulling Power

Samuel asks readers:

“Does one of your blog followers know a way to add weight to my 2 Ho locos to increase their pulling power? Also how to distribute the weight over the wheelbase?”

21 Responses to Correct Weight Distribution to Increase Locomotive Pulling Power

  • Will Shepherd says:

    Check out Bullfrog Snot for greater traction

  • Stephen Duncan says:

    Samuel, it depends on where you can find space in the shell. Sometimes you can find weights actually designed for the engine you have, noteably some for the old athern blue box ones, that fit over the frame. You can purchase tape backed weights from a model supply store and build those up in the available space. Those can be clipped as needed and balanced fore and aft of the engine to spread out the weight. NMRA has some suggested standards, but pretty much too much cuts down your total power, just enough increases the tractive effort.

  • Kevin says:

    Hi Samuel
    There are a lot of examples that are displayed on You tube some will be on your particular engines these are available on the internet as marked weights with double sided tape fitted to one side of the weights One that comes to mind was talked about on Whats Neat with Ken Patterson but I am not sure witch on so you would have to search this.

  • Ralph Cunningham says:

    I have increased the tractive effort on many locos by adding weight. This puts moor “push” down on the drivers (steam or diesel) making them pull better. You have to be careful that you are not overloading the motor or it will burn out. I mostly used lead and melted it to the form I needed, round for steamers and whatever form for diesels. Some people use nuts or bolts but I strongly recommend the lead method, You can get it in sheets and form it to the required shape elimating the melting and forming.

    • Joe deBy, Peterborough ON says:

      I solved this problem a great many years ago when coming at it in reverse. I’d built an all wood craftsman box car kit. When I realized that by using good trucks with metal wheels I didn’t need heavy cars, out came the weights in rolling stock. I try to keep 40-foot cars to 65 grams, increasing by roughly 15 grams per scale 10 feet. Amazing results came from tiny 1-mousepower locos ever since.

  • Larry Somers says:

    Bulldog snot on 2 of the drive wheels.

  • Mitchell Wade says:

    Everyone above is correct. I added weight to my Athearn P42 locos (about 4-6 oz) on the frame and in various places inside of the shell. They are pulling beasts now although I did repower one with a Kato HM5 motor.

  • John Lightfoot says:

    Hi Samuel,
    One of the most common problems with a loco not pulling enough is that the wagons/carriages your pulling are running with dry axles.
    All too often I have seen locos struggling to lift a load of wagons until I suggest and clean where the axle runs and apply lubrication.
    If you have the old Hornby through axle carriages well even with oiling they are hard to pull.
    I use Automatic Transmission fluid as a lubricant and have never had a problem in the last 15 years using it, is your loco running dry as well?
    What I mean by that is the axles lubricated so they make good contact with the chassis?
    Also you can use the stick on wheel weight available from a tyre place as they are fairly cheap from there.
    Its very hard to correctly advise you as to what to do as you haven’t listed what sort/brand of loco that you are using.
    But look at the wagon and carriage running abilities firstly.
    Hope this helps.

    Cheers,
    John.

  • phil r johnson says:

    depends on how many axles are powered. I generally use stick on weights inside the shell & over the trucks. however, this is difficult on steam engines since their weight should be evenly distributed over their main drivers. you should also monitor your motor current draw (amps). As John above mentioned, check you cars. metal wheels roll much better than plastic. I also use a bearing reamer(called “the tool”) on all of my plastic trucks.

  • John Lebsanft says:

    I ask, WHAT is bullfrog snot ? Have heard it mentioned but it has me intrigued.

    • David STOKES says:

      It is a proprietry liquid rubber product which is applied to the wheel treads. Care must be used in using it, but it works.

  • David Broad says:

    I haven’t used Bullfrog Snot but I abandoned traction tyres because they make the track dirty so I guess the snot has the same issues.

    I use lead, flashing from roofs, old lead water pipes melted down, old car wheel balance weights etc.
    I hammer the flashing to compress it, and make moulds to melt the other lead into.
    It is important to get the weight within the loco drive wheelbase on steam locos as two axles with 1kg each pull a lot better than one with 2kg. 4-4-0 and 4-6-0 chassis are particularly bad and lightening the front of one 4-6-0 actually made it pull better, Likewise getting the weight out from the back of 0-4-2T and 0-4-4T locos can improve haulage.

  • Mark Cartwright says:

    I find myself in some disagreement with nearly every other Poster here.
    First off, like UP and the BNSF, I suggest you look at the % they use for Grades as their maximum. I too use 1.5%. Too tight a radius also adds friction to your train. I don’t use Bullfrog Snot and have found myself removing and replacing wheels which sport traction tires. Since I run DCC with Sound in N Scale, weight and traction tires (dirt) can actually become an issue. The one Poster, I do agree with …Is keep your locomotives clean and free of debris. Plus…Go through them and file/sand any friction issues which are often found in even new locomotives. Remove all of the heavy caked in grease. I use a touch of light machine oil, and seldom any grease at all.
    AFTER…all of the above have been accomplished and before you turn to adding weight. Smooth your rails and perhaps solder in between each joint using a template to keep even the inside rails joined up properly. Make sure your track is evenly laid that is flat…with no dips or bumps. I then take a Rifler File to file inside rails and check for smooth runs, in the same way John Allen did…not by an NMRA Gauge but by simply rolling a metal wheel truck over the track.
    Ready for the Weights?
    Tungsten not Lead. I measure them carefully per car but also per train. So the entire train has a Center of Gravity down the center axis of the entire train. I don’t just add a clump of weight but gradually increase the weight. Some MTL cars don’t need any or maybe just a bit. I also convert eventually to body mounted couplers and Fox Valley Metal Wheels…but I test these as well…As they are made on a big machine in China and are not alway perfect. One more issue to mention…The Driveline in your Locomotive may actually be working against itself. Watch it carefully and try to determine if it is kinking. Often the worm gear has burrs or berms (high spots) which are slowing it’s performance. The Idler gear too, may have a high spot on some of it’s teeth or not creviced enough for the opposing gear. I take nearly every one of my Locomotives a part when I first get it…Or simply run Tooth Paste through the gearing by hand and fingers. There are many forces acting upon a train. Such as even how the motors are skewed or woven with wire, along with the position/use of bearings and fly-wheels. One more which may not seem an issue…
    Ever see a Locomotive wobble to and fro…?
    The Wheels on many a Model Train are out of round. I have removed the wheel assembly and set it in a vice downed Dremel or other drill for it to spin. Then carefully perhaps with anther device, lightly touch the flange of the wheel with a flat file to see it if is round or to help make it so. Doesn’t take much so be patient. Then test the wheel/axle as it rolls down your 1.5% Grade. Does it want to roll straight down or turn off the Tracks?
    Has such a near perfect steam locomotive ever been produced in N Scale? Yes, the More/Lik Steam Locomotives which is why they first sold for nearly $1500.

  • Micro-Mark, and others, sell a reamer that trues up the bearing surface of the truck sideframes. Most are not perfectly conical and drag on the pointed ends of the axels. You remove the wheel and replace it with the reamer, then twirl it between your fingers. You won’t believe how much plastic is removed. My personal experience is that it’ll allow train length to increase by 20%. Further, trucks operate best when the axle side play is about .015. Excess side movement will negatively impact performance.

  • David STOKES says:

    You don’t state whether you are having trouble with diesel or steam outline locos. Most of the above “cures” are directed to diesel locos. If adding weight to steam outline locos make sure it is balanced over the driving wheels because unbalancing the loco could make it an even weaker puller.

  • William Anderson says:

    Not mentioned in previous comments is the use of led shot for weight. It is available at sporting goods shops in various sizes and is easy to glue into close spaces to properly distribute the weight as needed.

  • W Rusty Lane says:

    The best weights I´ve ever used was linoType; it comes in just the right size to add to any train. I simply glued them down on the inside chassis with some tacky glue. The weights work to bring the car weight to NMRA standards. It´s also good to have a digital scale to weigh each piece of rolling stock to get them to NMRA standards.

  • Sheldon Clark says:

    Glue in fishing weights (“lead shot” – though I don’t think it’s actually lead nowadays – too poisonous) or shot supplied by gun shops for home filling shotgun cartridges.

  • Mr Chris Jordan says:

    There is a product on the market here in the UK that has a good self adhesive backing to various sizes of weights. I purchased some last year- but sadly the weights themselves do not have an identification name on them and the model shop I purchased them from has sadly closed down – No young person to take over the business- Arcadia Rail International Models -Railway Models & Accessories Mr Tim Housley owner may have stocks. he also has an Internet site kind regards Chris Aged(70) been doing railways since I was 5 years old.

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