LOADING AND UNLOADING CARS 
365 
a pair of trucks at l)oth the forward and the rear ends, on which 
the loader travels. The frames to which these trucks are at- 
tached and the trucks themselves are so hung on a shaft under 
the floor of the deck that during the loading operation they may 
be brought to a horizontal position untler the loader. The 
machine is then supported on the ties by the spuds. When ready 
to move, the weight of the loader is lifted from the spuds by 
bringing the truck frames to a vertical position by means of cables 
Fig. 125. — The McGiffert Log Loader. 
and other mechanism. This raises the loader from the spuds 
ready for a change of base. Power is tran.smitted to the axles 
of the trucks by means of sprocket chains. 
This machine has a boom which can swing through an arc of 
approximately 40 degrees and is adapted for longer logs and wider 
gauge roads than the Decker because of the greater space between 
the rail and the deck. 
{g) Surry Parker. — This loader embodies the same general 
principles as the two loaders previously described, having the 
upper deck high enough to permit loaded flat cars to be run under 
it. An early type was built without a device for transporting 
itself, being carried about on a flat car. The modern type of 
machine, however, is portable, the power being transferred from 
the engines to the axles by a chain drive. 
