Locomotive 493: Conversion from Coal-Fired to Oil-Burning The Conversion Begins
Because of long-term drought conditions and changing climate patterns in Southwest Colorado, the Durango & Silverton Narrow Gauge Railroad is evolving its operations, in part, by diversifying its locomotive power so that it can more safely transport passengers year-round regardless of weather conditions.
One of the ways it is doing this is by converting one of its K-37 Class locomotives, the 493, from a coal‚ locomotive to an oil-fired one as part of the scheduled rebuild of the engine. Locomotive 493 was originally built in 1902- as a standard gauge locomotive- and rebuilt in 1928 to its current narrow-gauge configuration. The 493 last ran in regular service 50 years ago in July 1968. It is one of two K37 locomotives currently owned by the D&SNG 498 being the other- they are the largest engines currently owned by the D&SNG. The 493 was selected in part because of the size and configuration of the firebox.
Conversion of the 493 coal-burning locomotive to an oil-burning one has been a huge undertaking for the Roundhouse crew. Many sources and other locomotives have been referenced and researched in the process but in general we are using many of the Southern Pacific oil fire standard set ups and practices during this painstaking endeavor. Here is a brief rundown of recent work which has mainly involved the tender tank and running gear.
On the locomotive itself, the drivers are all out, pressed apart and the wheels are in the process of being re-profiled. The next steps of running gear work will be spring rigging rebuilding and driver box work.
With the drivers out, the frame has been stripped of decades of layers of paint and grease down to bare metal. Boiler work is currently concentrated on replacing what seems to be an endless amount of boiler studs, to finish cleaning up the rear tube sheet. Also in progress is the forming of new rear firebox corners.
A total of 486 flexible staybolts will be installed in the next few weeks (placement of these are marked in blue in the photo directly above). Lastly, the ash pan, the final remnant of the coal-fired 493, has been removed. Additionally, we have acquired a burner, firing valve and are close to a final decision on a new fire door. See below for a fascinating look into the transformation of the 493 and stay tuned for future updates!
Roundhouse crew member Charlie Moore, below, working on cleaning up the tender frame and preparing to replace the old wooden end sills with more durable steel ones. In the meantime, new tender springs are under construction.