Articles

Canadian Pacific 2317 Tire Change
Photographs by Ken Ganz - Author unknown.
 
 

Canadian Pacific Railway 4-6-2 Pacific class G3c number 2317 at Steamtown in Scranton, Pennsylvania.
 
 

  Introduction

Currently (April 2011), Canadian Pacific steam locomotive number 2317 is out-of-service at Steamtown in Scranton, Pennsylvania, USA, due to a 1,472-day American Federally mandated inspection requirement. But back in 2007 the locomotive received a new set of tires for its driving wheels. The story that follows describes the process of a tire change, nothing like a tire change one would perform on a car. Read on...
 

  Tire Change

On 14 Mar 2007 the Steamtown Locomotive Shop staff replaced two tires on the main drive wheels of Canadian Pacific 2317. The old tires were "sweated" off, new ones installed, and then re-cut to the proper diameter. This virtual tour shows how the new tire is put on the drive wheel. These are two new tires for Canadian Pacific 2317. New tires may be needed for many reasons, the tire or the flange is too thin (possibly from too many re-shaping's on a lathe) or the tire is damaged. Canadian Pacific 2317's third drive axle's tires had very thin flanges.

The tire is cut 55/1000s of an inch smaller than the wheel it will be fit on. Steel expands when it is heated, so a gas ring will be fitted around the tire.

Just like a car, only the tire is replaced. The wheels are individual sand-castings and, even a hundred years ago, were very expensive. The thin rolled-steel ring (the tire) is much cheaper. A stand holds the wheel set (wheels and axle) off the floor.

Each tire is cut for one, and only one, wheel. Wheels on the same axle can be off by a hundredth on an inch or more, so when the inner diameter of the tire is trimmed (it must be 55/1000's of an inch smaller than the wheel), it must match the wheel. This drive wheel is 67.956 inches in diameter (5 feet 7 inches).

A Steamtown Preservation Specialist creates a bracket to help install the tire. The bracket fits on the forks of a forklift and hold the tire against the wheel during the heating process. Often, Steamtown's Locomotive Shop staff must create a tool before working with these historic machines.

This bracket, made in the Steamtown Locomotive Shop, holds the new tire slightly above the wheel. When the tire is heated to the proper temperature, and has expanded, workers slide it onto the wheel using sledge hammers.

A Steamtown Preservation Specialist positions a lifting band on a tire.

The new tire is relatively light (only a few hundred pounds) so the small hook on the overhead crane is used. This must be done slowly and carefully to avoid damaging the rolled steel tire.

As the tire is lifted to vertical, any oscillations are damped to prevent damage.

The tire is lowered onto the bracket. After the straps are removed, the next step is placement of the gas ring.

The gas ring is in place around the new tire. Fed by hoses at the bottom, the gas/oxygen mixture travels though the ring and out small holes.

The flame is lit and swiftly envelops the new tire.

The flow of oxygen is cut back to produce a bluish flame which burns much hotter.

A close up of the flames at the bottom of the new tire. The new tire must be heated to about 200 to 250 degrees F above the ambient temperature to expand enough to slide over the wheel.

A Steamtown Preservation Specialist uses a sensor to check the temperature of the steel wheel. The wheel must be hot enough (around 300 to 350 degrees F) to expand, but must not exceed 600 degrees. Above 600 degrees, the temperature may change the steel altering how much it can flex.

A Steamtown Preservation Specialist uses a sledgehammer to move the tire onto the wheel. Steam railroading is an odd combination of measuring to within a thousandth of an inch, and then using a large blunt tool to achieve results.

The gas ring is removed and workers check to ensure the tire is fully on the wheel.

Workers ensure that the new tire is properly mounted on the wheel.

Clamps hold the tire in place on the wheel as it cools. As the tire shrinks onto the wheel tension between the tire and wheel holds the tire in place.

A Steamtown Volunteer-in-Park (VIP) uses a wheel lathe to cut the new tires. Only one set of tires (one axle) is being replaced and all the drive wheels of a steam locomotive must be the same diameter because they are linked with connecting rods.

As the drive wheel set rotates in the lathe, a cutting blade removes a quarter-inch deep "shaving" from the new tire. When the diameter approaches the size of the old tire, a different blade does the final shaping.

Canadian Pacific 2317 rests in the shop as visitors tour the facility.
 
Thank you for your time. We hope you enjoyed this "virtual tour" showing one of many activities in Steamtown's Locomotive Shop. Steamtown offers walking tours of the Locomotive Shop on most days. Some lucky visitors were able to see the "ring of fire" during their tour.