THE SIGNAL BOX

OVERSEAS

GLEN YARD
Canadian Pacific

by John Hinson

Interior of tower at Glen Yard
Photograph from the collection of Dr J W F Scrimgeour

The tower at Glen Yard, between Montreal Windsor station and Montreal West, was opened in 1923. The Canadian Pacific installed a 25-lever Federal Electric miniature-lever frame to control the junction between the main line and the yard. The FE frames were an interesting mixture of old and new technology. Taking the term miniature lever to the most literal extent, these were in fact miniaturised versions of the full-size frames made by the Union Switch & Signal Co, with Saxby & Farmer-style rockers driving mechanical interlocking behind the levers. The functions of the levers themselves were, of course, power-driven.

Above the levers are clockwork time release controls in glass jars - those used in the UK were popularly called pickle jars. Operation is achieved by turning the knob on the front, starting the timing process driven by the clockwork spring. After the prescribed time has elapsed, the backlock on the lever concerned is released. Before that lever can be operated again, the knob has to be reset to its original position, the process of which rewinds the spring. The common use for this type of device was on the signal lever at facing points, enforcing a time delay (if the signal has had to be replaced for some reason) before the lever could be fully replaced and the points moved.


Comments about this article should be addressed to John Hinson