The reference for locomotives and railcars
Santa Fé class 3000
United States | 1911 | 10 produced
The first vehicle built, No. 3000
The first vehicle built, No. 3000
Detroit Publishing Co.

In order to explore the extreme limits of the Mallet principle, the Atchinson, Topeka & Santa Fe developed the class 3000 in 1911 with the wheel arrangement 2-10-10-2 and a weight of 309 short tons. The goal was to be able to pull 2,000-ton trains with just one locomotive over gradients of 1.2 percent in Arizona. In order to speed up development and production, the running gear for each of the ten examples was taken from two standard Baldwin 2-10-2 locomotives and combined into one locomotive. The existing cylinders were used as rear high-pressure cylinders and Baldwin had larger low-pressure cylinders made for the front bogie. A special development was the flat six-axle tender with a rounded rear section, which was called “Turtleback” and was intended to provide better rear visibility. It contained oil for firing.

A normal boiler of the same length as the class 3000 could not be realized and therefore only the rear half was used as a classic boiler barrel with combustion chamber and smoke tubes. The front half was used as a feedwater heatersuperheater and reheater for the exhaust steam from the high-pressure cylinders. All in all, it was found that this boiler did not generate enough steam for the powerful engine and therefore sustained speeds of only 10 to 15 mph were possible.

In view of the low speeds, the locomotives were not used directly to pull heavy freight trains, but had to push other trains uphill. There they were mainly found in California on Cajon Pass and in the famous Tehachapi Loop. Nevertheless, the demolition of the first locomotives back to simple 2-10-2 locomotives began as early as 1915. When the last ones were dismantled in 1918, they had earned the nickname “magnificent failures”. Only the new design of the tender was considered successful and used in later Santa Fe locomotives.

Axle config2-10-10-2 (Mallet) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Length122 ft 0 3/16 in
Wheelbase66 ft 5 in
Fixed wheelbase19 ft 5 1/2 in
Total wheelbase108 ft 10 in
Service weight616,000 lbs
Adhesive weight550,000 lbs
Total weight882,450 lbs
Water capacity12,000 us gal
Fuel capacity4,000 us gal (oil)
Power sourcesteam
Estimated power3,000 hp (2,237 kW)
Optimal speed18 mph
Starting effort109,113 lbf
with start valve130,936 lbf
Power Plant
Driver diameter57 in
Boiler pressure225 psi
Expansion typecompound
Cylindersfour, HP: 28 x 32 in
and LP: 38 x 32 in
Grate area82 sq ft
Firebox area284.5 sq ft
Tube heating area3,637 sq ft
Evaporative heating area3,921.5 sq ft
Superheater area2,381 sq ft
Total heating area6,302.5 sq ft
Calculated Values
steam locomotive
last changed: 03/2022

We use cookies to save the following settings:

  • selected navigation structure
  • selected language
  • preferred units
  • spelling of railway company names

If you refuse the use of cookies, the settings will only be retained for the current session and will be reset to the default values the next time you visit the site.

Display of units

Here you can set the desired unit system for the technical data.

  • Metric: Lengths in meters, weights in tonnes, and volumes in cubic meters
  • Imperial (UK): Lengths in feet/inches, weights in long tons and volumes in imperial gallons
  • Imperial (US): Lengths in feet/inches, weights in pounds, and volumes in US gallons
  • Individual: Depends on the country of origin of each locomotive
Operator names

Here you can set the display of railway company names.

  • Short: Abbreviation or short form of the name
  • Standard: commonly used name, partially translated to English
  • Complete: full name in local language