This appears to be a part number for a diesel locomotive exhaust pipe. It is in the concrete block extension on the back end of stall #30. It is not known why it is here, but my conjecture is that when diesels were serviced at Crestline, this extension became a warehouse for diesel parts. Box cars could have been brought in the rear entrance and then unloaded. By now, the mid 1950's, only the west end of the round house was in use, diesels could have been serviced at the far west end, and what steam was still being serviced here, could have serviced in, say, stalls #22-26. This would segregate diesels from steam, yet both would be near the machine shop, and steam engine parts would still be stored in the warehouse, near the steam servicing area. Nov., 2001 (Photo courtesy of Matt Link)