A ship canal is a canal especially intended to accommodate ships used on the oceans, seas or lakes to which it is connected, as opposed to a barge canal intended to carry barges and other vessels specifically designed for river and/or canal navigation. Because of the constraints of accommodating vessels capable of navigating large bodies of open water, a ship canal typically offers deeper water and higher bridge clearances that a barge canal of similar vessel length and width constraints.
Ship canals may be specially constructed from the start to accommodate ships, or less frequently they may be enlarged barge canals, or canalized or channelized rivers. There are no specific minimum dimensions for ship canals, with the size being largely dictated by the size of ships in use nearby at the time of construction or enlargement.
Ship canals may be constructed for a number of reasons, including:
The Thun ship canal (German: Thun Schiffskanal) is a 500-metre (1,600 ft) long canal in the Swiss canton of Bern. Together with a navigable reach of the Aar river of similar length, it connects Lake Thun with a quay in the town of Thun adjacent to Thun railway station.
The canal allows shipping services on the lake to serve the town and connect with railway services. It is still in regular use by the Lake Thun passenger ships of the BLS AG.
Shipping services on Lake Thun date back to at least 1834, when the first steamship was introduced to connect the towns of Thun and Interlaken, at each end of the lake. Originally steamers docked at Scherzligen, and in 1861 the Bern–Thun railway line was extended to a terminal there.
In 1923, the station at Scherzligen was merged with that at Thun to create a new central station. Two years later, in 1925, the ship canal was constructed in order to retain the connection between trains and ships.