Recent Blogs
Stephenson Valve Gear
Stephenson valve gear explained — how the link motion controls steam admission, cutoff, and reverse on locomotives, with worked sizing example and tradeoffs.
Single Eccentric Variable Valve Throw
Single Eccentric Variable Valve Throw explained — how shifting one eccentric on a steam engine alters valve travel, cutoff, and power across operating range.
Marshall Valve Gear
Marshall valve gear explained — how the radial linkage controls steam admission and cutoff on traction engines, with formula, worked example and design tradeoffs.
Joy's Valve Gear
Joy's Valve Gear explained — radial valve gear without eccentrics, used on LNWR locomotives and marine engines. Geometry, formula, worked example, trade-offs.
Allan Straight-link Valve Gear
Allan straight-link valve gear explained — how the symmetric link reverses steam locomotive valves, design math, tolerances, and worked example for restorers.
Walschaerts Valve Gear
Walschaerts Valve Gear explained — how the linkage controls steam admission, cutoff, and reverse on locomotives, with formulas, tolerances, and worked examples.