When it comes to replacing a broken traction tire on a steam locomotive, it helps to have a sense of humor. That and a third hand. I don't have a third hand to lend you, but I can offer you the tips below to get a leg up on this friction-fraught task.
Traction tires have only recently become the norm in a world once ruled by Lionel's Magne-Traction. These days, if you run modern-era trains a lot, you'll end up with a tire that has worn smooth, broken, or simply been thrown off, usually exposing a grooved steel rim that insists you fill it with a good tire.
There's the rub. The task actually looks quite simple, but the challenge is that traction tires fit tightly, and that means you usually have to strrrretch them to wrap them around their rims.
Here's a method I used recently to replace a traction tire on a K-Line Pacific steamer that will help you with any brand of modern steam, diesel, or electric locomotive.
1. Place the locomotive upside down in a foam cradle or a cloth-lined tray to protect it and hold it steady still while you work.
2. Remove just enough of the steam locomotive's running gear to let you slip the replacement tire around the rim. If the tire goes on the rear-most drive wheel, you'll only have to remove one hex screw on that driver. To remove hex screws, buy a 1/4-inch socket set that contains both inch and millimeter sockets. Don't use a pair of pliers or vise grips; you'll damage the head of the hex screw. If the traction tire goes on a center driver or a front driver, you will need to disassemble more pieces. Always work on one side at a time, never work on both at once. Working one side at a time will keep the wheels properly quartered. It also allows you to reassemble the running gear using the untouched side as a guide.
3. Slip the tire in position and push it as much as you can into the gap between the driver needing the traction tire and its neighboring wheel. Once you got the tire in nice and flush, hold it firmly with two fingers, straddling the dangling siderod, if need be.
4. With a pair of tweezers or a similar tool in your other hand, stretch the traction tire around a third of the rim in any direction.
5. Here's the tricky part. Wedge the tweezers between the flange and something else (I used my padded stomach) to hold the tweezers steady. You have now found a third hand. Don't feel bad - in fact, laugh, if you can - if you don't get everything to stay in place the first time. Or the second time. Or even the third time. You're in good company.
6. Using a tool with a small round handle (I used a small round file), roll the rest of the tire onto the rim. You'll find that once you get about another third of the way around the rim, the final third of the tire almost seats itself.
7. Carefully withdraw your fingers and the tools from the seated tire and press fit the tire fully into the rim's groove. Make sure the flexible tire isn't twisted on the rim.
8. Reassemble the running gear and carefully allow the tire to set itself in place as you run the locomotive slowly on your layout.
That's pretty much the third-hand trick. For diesels and electric profile locomotives, the task is similar. Of course, you don't have any running gear to remove, but you may have to remove the truck sideframe to gain clear access to the wheel rim.
When you're done replacing the traction tire and your locomotive is once again steaming around your layout, smile broadly. You deserve it.