DRRY Index

   
Edward "Bud" Buker's Historic
Deerfield and Roundabout Railway
  
An educational demonstration steam powered
7 and 1/2 inch gauge railway operated by the
 
LAKE FOREST LIVE STEAMERS
RAILWAY MUSEUM INCORPORATED
 
Presents
 
STEAM LOCOMOTIVE VALVE GEAR ANIMATION VIDEOS
CREATED USING CHARLES J. DOCKSTADER'S
"Steam Engine Valve Gear on the Computer Program"
   

Links to Valve Gear Animation Videos

Stephenson Valve Gear Applied to Outside Admission Unbalanced Slide Valve

Walschaerts Valve Gear Applied to Inside Admission Piston Valve

Walschaerts Valve Gear Fundamental Geometric Relationships

Baker Valve Gear Applied to Inside Admission Piston Valve

Baker Valve Gear Fundamental Geometric Relationships

Southern Valve Gear Applied to Inside Admission Piston Valve

Valve Event, Cylinder Event and Valve Ellipse Diagram Explanation PDF

Notes to Valve Gear Animation Videos

For each of the three valve gear animations presented the reverse lever is illustrated in four positions described as full forward motion, forward motion near center; centered and full backward motion. Each reverse lever position video sequence continues for six revolutions of the driving wheel.

Steam passing into the valve chest or chamber, through the cylinder and exiting from the exhaust nozzle is represented by areas shaded with dots of four different colors. The appearance of the density of the dot pattern is intended to represent the relative steam pressure.

The colors of the dots are intended to represent the following:

RED - Steam at after throttle pressure or at a further diminished pressure within the cylinder caused by various restrictions to its flow before entering the cylinder.

MAGENTA - Steam expanding in the cylinder and diminishing in pressure after admission of steam into cylinder has been cut-off by the valve and before the point of release where the valve allows steam to exhaust from the cylinder to the exhaust nozzle, smoke stack and thus to atmosphere.

BLUE - Steam exhausting from the cylinder to the exhaust nozzle, smoke stack and thus to atmosphere.

GREEN - Exhaust steam remaining in cylinder compressing after the valve has closed the cylinder to exhaust and before the valve has opened to admit steam from the throttle into the cylinder.

Links to Additional Steam Locomotive Valve Gear Information

Valve Ellipse Diagram Detailed Series PDF

Deerfield and Roundabout Railway Engine No. 284 Valve Motion Report

Deerfield and Roundabout Railway Engine No. 326 Valve Motion Report