Brief Operating Instructions for Walschaerts Program (Windows Version).
(32-bit version - i.e requires W95, W98, or WME)

1. Preferably transfer files Walschaerts.exe AND wal_data.dat into the same directory on hard drive (Will work from floppy, but slowly!). Note that the two files must be in the same directory.

2. Double click on Walschaerts.exe. The Data Entry window opens.

3. Select an engine (e.g. 'britannia') Dimensions are transferred from data file ('wal_data.dat') to the window. If you want to know to what a particular dimension refers, click on 'Show Dimensions' and then click on the entry beside the dimension in question. (e.g. the 35.1 beside 'Combination lever')

4. Click 'GET RESULTS'. Not surprisingly the 'Results 'window opens! The top panel will show the inclination (to horizontal) of the lifting arm in mid-gear

5. Enter the lifting arm angle RELATIVE TO MID_GEAR (i.e. for mid-gear enter 0). Try 15 for Britannia. An 'oval' diagram appears together with a table of valve events, and other bits & pieces. Try 5, -5, -15 etc. The horizontal green lines on the oval diagram are lap lines,(where the valve begins to open), and the purple line is the port line (where the port is fully open)

6. Click on 'Animate'. The animation is produced by moving the mouse around.  Yes, you can also make it go in reverse! Also a small circle moves around the oval diagram to indicate the current position on that diagram corresponding to the position of the linkage.

Note: the data file contains information about the method of locating the radius rod, and the type of valve, so when you select an engine from the list the buttons in the 'Valve type' and 'Radius rod' boxes are automatically pressed. If you want to enter a new engine these buttons will have to be pressed before you enter the dimensions. Don't forget to Save a new engine after entering the dimensions.

