Steam Locomotion in the 21st CenturyThe Recent History of Steam Locomotive Development
US2691455 A patent by boiler manufacturer Babcock &
Wilcox for an improved tender arrangement.
Franklin Poppet Valves-
US2401764 Applied to a few modern steam locomotives in the
U.S.; offered improved steam distribution over conventional piston
Drive System for
Franklin Type "A" Poppet Valves- US2183327 Shows the mechanism for operating
Franklin Type "A" or "OC" (oscillating cam) poppet valves.
Reverse Gear for Franklin Type "A" Poppet Valves US2385957
Franklin Rotary Cam
Type "B" Poppet Valves US2441156 Shows the valve
arrangement for Franklin Type "B" or "RC" (rotary cam) poppet
Franklin Rotary Cam Drive System- US2441199 Shows the drive system for Franklin Type "B" or "RC" (rotary cam) poppet valves.
*Franklin Type "C"
"Long Compression" Poppet Valves- US2518403 A
development of the Type B rotary cam poppets, the camshaft
profiles were designed to improve the starting and low-speed
traction of steam locomotives, one of their weak points compared
"B-1" Rotary Cam Poppet Valves US2518024 A late development which eliminated
the need for manual cut-off adjustment by the engineer. The
valves were controlled with a three-position lever with forward,
"neutral" and reverse positions. Steam admission was regulated
by a fairly complex cam profile which effectively gave full
steam admission at low speeds, partial admission at medium
speeds, and short admission at higher speeds. This gear was
installed on only one steam locomotive US Army Transportation
Corps (USATC) 2-8-0 611, which was preserved and currently
belongs to a private owner. Franklin engineer Raymond Delano
claimed that this gear gave similar steam economy while being
significantly easier to repair and adjust compared to
conventional piston valves.
Watertube boiler patent #4 US2366465 (high-wheeled locomotive)