Canal Lake Concrete Arch Bridge

Canal Lake Concrete Arch Bridge
Coordinates	44°33′29″N 79°02′45″W / 44.55801°N 79.04592°W / 44.55801; -79.04592Coordinates: 44°33′29″N 79°02′45″W / 44.55801°N 79.04592°W / 44.55801; -79.04592
Carries	Centennial Park Road
Crosses	Canal Lake
Locale	Kawartha Lakes (Ontario)
Owner	City of Kawartha Lakes
Heritage status	National Historic Sites of Canada
Characteristics
Material	Reinforced concrete
Total length	202 feet (62 m)
Width	16 feet (4.9 m)
Height	29 feet (8.8 m)
Water depth	up to 15 feet (4.6 m)
No. of spans	1
Clearance below	29 feet (8.8 m)
No. of lanes	2
History
Designer	Department of Railways and Canals
Construction start	1905
Construction end	1905
Opened	1905
National Historic Site of Canada
Official name	Canal Lake Concrete Arch Bridge National Historic Site of Canada
Designated	24 June 1988
Canal Lake Concrete Arch Bridge Location in Southern Ontario

Canal Lake Concrete Arch Bridge is an arch bridge in Ontario, Canada, spanning a portion of Canal Lake on the Trent–Severn Waterway between Balsam Lake and Lake Simcoe. It is north-northeast from the town of Bolsover.

The closed spandrel bridge is the earliest-known bridge in Canada to be constructed using reinforced concrete, and is based on a modified Melan System of bridge reinforcement. In 1988, it was designated a National Historic Site of Canada for representing a transitional period in bridge construction and a milestone in civil engineering in Canada.

Designed by the federal Department of Railways and Canals, the bridge was built in 1905. The original design was for a concrete arch bridge typical of its era. Before construction began, the design was updated by integrating reinforced concrete using a modified Melan System of bridge reinforcement, which had been pioneered by its namesake Josef Melan in the 1890s. Among the changes were the installation of struts underneath the arch, and a reduction in the mass of the arch and its abutments. The concrete mass is reinforced with curved steel girders.

The arch is a closed spandrel, in which the structural load of the deck is carried to the arch ribs via spandrel walls. It has a radius of 30 feet (9.1 m), and its vertical clearance of 29 feet (8.8 m) is sufficient for vessels to navigate underneath. The deck is 16 feet (4.9 m) wide, and spans 202 feet (62 m) over the lake, anchored by reinforced concrete abutments. The concrete spandrel walls are marked to imitate the voussoir layout common to stone arch bridges and the "coursed stonework of stone masonry bridge abutments".