Bridge Powerscourt, historical monument, is a civil engineering structure built in 1861 and 1862. This covered bridge type McCallum has two arched spans and rests on three pillars. Its wooden structure painted red is covered with a gable roof. Powerscourt Bridge, which spans the Châteauguay River in a heavily wooded area, connects the municipalities of Elgin and Hinchinbrooke.
The heritage value of the bridge Powerscourt based on its technological relevance, originality and uniqueness. This wooden bridge is built according to the “inflexible in dual beam” invented in 1851 by engineer states unien Daniel Craig McCallum (1815-1878) for the purposes of rail technology. The rigid and extremely durable structure bridges McCallum type is designed to support the weight of a train. It consists of an assembly firm and inflexible arcs that prevents vibration wooden bridges to long range when passing convoys. This model is not widespread because of its complexity and precision of execution that requires and is only used for two decades, until the advent of steel bridges. United States, 150 McCallum-type bridges were built by railroad companies while Quebec has counted ten, nine of which were erected in 1858 and 1859 on the lines of the Grand Trunk Railway. The use of this model to a road bridge as the Powerscourt is quite unusual. This covered bridge is the only known structure McCallum type subsist example, in Quebec and in Canada and the United States. It is therefore a valuable and unique testimony of civil engineering.
The heritage value of the bridge Powerscourt is also based on his interest in the history of transportation and seniority. The mid-nineteenth century, the elected representatives of townships in southwestern Quebec are concerned with the development and improvement of their roads. Among the work done at the time it appears and bridge, erected in 1862 on the Châteauguay River, which connects the cantons of Elgin and Hinchinbrooke. Since the early nineteenth century, even in the late eighteenth century, covered wooden bridges are already part of the Quebec road network. The roof protects the structure from weather and increases durability. The majority, however, are covered bridges built in areas of recent colonization, between 1890 and 1950. They become obsolete with the modernization of the road network and the last were built in the 1950s. A few thousand covered bridges in Quebec, it remains today less than a hundred, and the bridge is the oldest Powerscourt. It is also one of the oldest covered bridges kept in Canada. Always used as a road link, so it embodies a type now rare structure in the transport network in Quebec.
The characteristic elements of the bridge Powerscourt include the following:
- Its location on the Châteauguay River at the tip of an island in the middle of a heavily wooded area;
- Its wooden structure McCallum-type, the upper strings farms formed by rigid arches and equipped with poles perpendicular to the curvature, the ties placed diagonally, crows and wooden struts;
- Two arched spans paneled vertical batten boards painted red;
- Arched roof gable low slope covered with sheet;
- Lateral openings in the upper walls directly below the roof;
- The central pillar masonry quarry stone as a foundation element.
Chemin de la 1 Concession, Powerscourt, QC J0S 2E0