SP 4449 - Booster Truck Rolling Bearing Project

Booster Truck Roller Bearing Project
April 2005

The 4449 was built with friction bearings, and still runs that way today with the exception of the tender being equipped with roller bearings. Time has come to ease maintenance and go for a smoother ride by starting with the last 2 axles of the locomotive, located directly beneath the cab.

These 2 axles are located in the "booster truck", which is also steam-driven to give the locomotive a head-start on steep grades or with a heavy train behind it before the big cylinders take charge. Upgrading them to roller bearings eliminates the need for continious lubrication and inspection, and provides a smoother ride for the crew inside the locomotive's cab.

Once the pit's uncovered and the locomotive is spotted with the first booster axle directly on the drop table, the crew dismantles the bearing cases and covers. The brakes also had to be detatched from the wheel, kind of like unhooking the rubber brake shoes before removing a bicycle tire.

Even with the nuts and bolts removed, casing opened, the axle wouldn't budge. More time was spent on figuring out what was keeping the axle locked in tight -- This included some torching, pounding, and needle-gunning (with some breaks in between!)

Now that all obstacles are freed, the axle is cleared to leave the locomotive. Skylar operates a hydraulic-powered lift that lowers the drop pit, which the axle is sitting on. Doyle and Pat pay close attention to ensure the axle does not catch on either side, thus causing the wheel on the opposite side to fall between the rails.

Once the axle is fully lowered into the pit, the transfer table is located to the shop track, and the axle is raised back to ground level. Once there, the crew pushed the axle off the drop pit towards the fork lift, and the axle is shipped out to be machined for roller bearings.

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Preparing to leave Portland, OR for Pasco, WA