Rideau Canal – Lower Brewers swing bridge

Rideau Canal,Lower Brewers,Lock 45,swing bridge,timber king post swing bridge

The swing bridge at Lower Brewers is an authentic replacement that replaces the original 1872 structure and is one of only four still in operation on the Rideau Canal System, the others at Kilmarnock, Nicholsons, and Brass Point.

Rideau Canal,Lower Brewers,Lock 45,swing bridge,timber king post swing bridge

The swing bridge is balanced on a pintle and pushed by hand.

Robert W. Passfield, a renowned expert on rideau bridge construction explains why the Rideau bridges are not Kingpost Truss Bridges:

"The Rideau Canal swing bridges are strengthened by a triangular truss with a center post similar to a conventional kingpost truss, and have been commonly referred to as "kingpost truss swing bridges", but that is an error. In a kingpost truss the truss arms are in compression in carrying the weight of the bridge span, and its live load, to the extremities of the bridge on the abutments, and the kingpost is in tension in holding up the center of the span to keep it from sagging. Hence, the truss arms need to be of a rigid, heavy wood construction. In contrast, on the Rideau Canal swing bridges the main post is in compression over the pivot beam of the swing span in supporting the truss arms, which extend to both ends of the swing span. They are in tension in holding up the extremities of the swing span to keep them from sagging when the span is swung open. Hence, the truss arms are lighter wrought iron rods. Although the conventional kingpost truss and the Rideau Canal swing bridge truss are similar in appearance, they differ widely in their structural function."

Rideau Canal,Lower Brewers,Lock 45,swing bridge,timber king post swing bridge

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