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The Welland Canal Bridge 15 is a two-track Baltimore truss swing bridge located in the disused section of the Welland Canal within the city of Welland, Ontario. This section of canal is now known as the Welland Recreational Waterway. The bridge formerly carried the main line of the Canada Southern Railway (CASO) over the canal. As a result of the Welland Canal Relocation Project in the early 1970s, the CASO line was rerouted through the Townline Tunnel, bypassing this bridge. One track crossing Bridge 15 remained in service as an interchange line between the Canadian National Railway Canal Subdivision through Welland and the new Wainfleet Marshalling Yard at Wainfleet, Ontario. In the late 1980s, service on this line between Welland and Wainfleet ended and the track was removed between Wainfleet and a point a couple of hundred meters west of Bridge 15. The bridge remains in use today exclusively to serve Vesuvius Industries in Welland. It is owned by the Canadian Pacific Railway (CPR), but is not connected to any other CPR tracks. It is used only sporadically by Trillium Railway, and chain link fence gates have been installed at both ends of the bridge to keep trespassers off. Bridge 15 is visually similar to the Montrose Swing Bridge located on the Welland River approximately 15 km away; however, that bridge is a Warren Truss, as opposed to the rarer Baltimore Truss of Bridge 15. The two bridges were constructed at approximately the same time. The Niagara, St. Catharines and Toronto Railway Swing Bridge over the canal (Bridge 8) at Thorold, Ontario was also constructed at approximately the same time. That bridge, built for interurbans and light electric freight locomotives, was a lighter construction and only carried a single track. Bridge 8 no longer exists. == Design and construction == Bridge 15 was built ca. 1910 as a replacement for a wooden bridge formerly at the same location. During this time, the Third Welland Canal was still in use, however the need for expansion of the canal had been recognized. Accordingly, any new bridges were being constructed to standards which were expected to apply to the Fourth Welland Canal, which would not be completed until 1932. As will be discussed later in this article, these standards were not set high enough and this fact would make the swing bridge a serious hazard to navigation decades down the road. During the early years of its existence, prior to the opening of the fourth canal, navigation was only possible to the east side of the bridge. Electrical power to operate the bridge was supplied via an overhead cable from the west shore. With the opening of the fourth canal, there was navigable water on both sides making an overhead wire impossible. Since the bridge was designed to have the power fed from overhead and not beneath, an underwater cable was run from the shore to the more northerly concrete fender (which protected the ends of the bridge from ships when it swung). A pole was erected on each fender, and a guy wire run between them directly over the bridge. The power cable was suspended from this guy wire to reach the top-hat-shaped device in the middle of the bridge which transferred the power to the rotating bridge. This top-hat, and the two poles on the fenders, are still visible today. This is a relatively unusual method of providing power to a swing bridge. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Welland Canal, Bridge 15」の詳細全文を読む スポンサード リンク
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