A 1940 employees timetable gives the following information:
Maximum Speed for narrow gauge passenger trains - 35 MPH
Maximum speed for narrow gauge freight trains - 25 MPH
Maximum speed for K36 & K37 engines 30 MPH
Train 215 (San Juan) used 1:05 from departure in Alamosa to departure from Antonito - 28.6 mi at an average speed of 26.5 mph. However, that includes stops in La Jara, Romeo and Antonito (and cutting out the Santa Fe Br cars in Antonito). If you add 5 minutes for each stop the average speed comes to 34.5 mph. If you figure into the average, picking your way through Alamosa yard, 12 mph slow order through Antonito, and accelerating the train out of the stops, the average has got to hit at LEAST 35 mph on a daily basis.
The Shavano (Tr 315 & 316) was slightly less speedy. In the short stretch from Salida to the bottom of the 4% at Poncha Jct (5 miles) it averaged 21.7 mph - including getting out of Salida. I would guess they did closer to 25 once out of town. From Sargent to Gunnison, they took 1:14 to cover 31.4 miles with 2 stops averaging 24.8 MPH. Figuring 5 minutes per stop the average hits a respectible 29.1 mph.
To specifically answer Wade's question about the Silverton Branch, the 1940 timetable shows a the average speed at a thunderous 13.6 mph.
Appearently somebody figured out to run the San Juan on schedule, you had to break the rules. Especially if you had a 480 as power. In a 1949 employees timetable the max speed for narrow gauge passenger trains is raised to 40 MPH, and the maximum speed for K36-37's is raised to 35 MPH.
I have to agree that a K36-37 would have a tough time getting above 35 mph and staying either on the rail or staying in one piece. Remember the narrow gauge in itself creates an instability, dispite the lower center of gravity. A one inch low joint on SG is no where near as big a bump as it is on the NG.
K36 -37's have very heavy running gear for thier size. Comparing them to similar sized standard gauge locomotives, you will note the rods are much larger and heavier that on a SG engine. Counter balance on smaller drivered locomotives is a tougher problem with heavy rods. I've seen Sierra RR #34 (a standard gauge virtual twin to a 480 but with much lighter rods) breeze along at 30 and ride like Pullman taking low joints in stride. I've been on 489 at.. uh... well... a REAL HEALTHLY 22 MPH (that's my story and I'm sticking to it) when a low joint nearly sent me across the cab.
I should point out the addition of the 3rd rail made for a very stable railroad. Jim Shawcroft told me once that as soon as the 3rd rail came out, the Antonito line's track went to hell in about 2 months.
