Alan and Barry preparing the machine for the demo.

A view from the top. The upper layer can beside beyond the main section.

A front view of the machine without the upper layer. The programming boxes can be seen at the right-hand end, and the selection drums at the left hand end. The front half controls the backstroke, and the rear half the handstroke.

Another front view showing the eccentrics that move the action bars.

The underside of the top layer. Part of the swapping mechanism visible.

An enlarged model of the swopping mechanism.