Which was the better system: High pressure oil lube for axles like SP used or roller bearings?
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A locomotive must move before the oil system works well. The roller bearing is ready right away.
The other fact about roller bearings is that the cars in a train are equipped as well, making starts much, much easier.
The standing weight of a locomotive, tender or frieght car causes the axle to rest right on a friction bearing, causing high starting efforts.
Ed
The SP's patented pressure feed"spring pad oil lubrication" system worked very well. In the mid 30's after the GS-2s were equipped with the spring pad oil system (the drivers remained grease for a time), SP began a move to convert most 'big power' (the MT 4-8-2s in particular) to the oil system.
All subsequent orders of 4-8-4s from the GS-3s through GS-6 were equipped with the pressure feed spring pad oil lubrication system, save for the two GS-5 (4458 and 4459, which were equipped with Timken and SKF roller bearings, respectively).
The 4449 is still equipped with the spring pad oil system on the drivers.
DV
Originally Posted by DominicMazoch:
Which was the better system: High pressure oil lube for axles like SP used or roller bearings?
Obviously roller bearings where, and still are, superior. That said, since the Southern Pacific Mechanical Dept. developed and patented the "spring pad oil lubricated, pressure feed" bearing system (which also requires babbitted plain bearings), and felt no need to pay extra money for roller bearings, since what they had,,,,,worked.
It should be noted however, that the SP was NOT a "high speed" railroad such as the AT&SF, UP, CMStP&P, and NYC, for example, and thus really saw no benefit in the extra cost of the maintenance free roller bearings on all axles. As a result, the Southern Pacific had only two steam locomotives equipped with roller bearings (GS-5 #4458 & #4459) throughout their entire history.
