Saturday, May 10, 2008

308 Inspection


Today I did the annual inspection on car 308. But since you weren't there, here's what you missed:







The car ran over to the pit in Barn 4, where I was able to inspect the motors from underneath. To the right, we see a traction motor with the bottom covers removed - and by the way, those covers are heavy! The "commutator" is composed of 195 copper bars which carry current to the windings in the rotating part of the motor. The commutator should be (relatively) clean, and the gaps between the bars should be free of excess dirt or carbon dust. To the right of the commutator, we see the edge of the bottom pole piece winding. The most important step is to check the clearance between the armature (the rotating part of the motor) and the bottom pole piece. If the armature bearings become worn, the armature drops down far enough to hit the pole piece, and then we've got a serious problem. The motor probably won't turn, at least not without destroying itself. Incidentally, the clearance is checked with a large dipstick from a truck motor.

To the left we see how the traction motor is suspended on the axle by two bearing boxes called "axle caps" which are marked in red. These are attached to the motor by large bolts ( 2 1/4"), and they must be checked for tightness.

The annual inspection sheet is a four page list of things to check and lubricate, so there's more than I can easily summarize here. It's exhausting, but I didn't find anything wrong. Actually, I didn't quite finish the entire inspection - the roof equipments need to be checked, and then there's the interior parts such as windows and doors. The interior stuff is known to be in good shape, and the roof I can do when there's somebody around for safety. In any case, the car will be ready for revenue service this year. Whew!

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