Linkspan
From Wikipedia, the free encyclopedia
A linkspan or link-span is a device used mainly in the operation of moving vehicles on and off a Ro-Ro vessel or ferry.
Linkspans are usually found at ferry terminals where a vessel uses a combination of ramps either at the stern, bow or side (or a combination of any) to load or unload cars, vans, trucks and buses onto the shore.
Contents |
[edit] Brief history
Before the introduction of these devices, vehicles were loaded onto vessels by either hoists via ship/shore based derricks or a lift hoist fitted to the vessel which usually consisted of a platform that could be raised to the dock side to allow cars to drive straight onto the lift, then lowered so that cars could drive off onto the car deck - a very slow process.
Linkspans were expensive but time saving, and allowed operators to load cars straight into the car deck, alleviating the need to match the car deck height with that of the pier.
[edit] How it works
A linkspan is effectively a ramp that is attached to the pier at one end and is suspended above the water at the other. The height above the water is controlled either by hydraulic rams or cables under the control of an operator, who adjusts the height according to the tide. The aim of all this is to have the linkspan suspended at the roughly same height above the water as that of the car deck on whichever ferry happens to be docking at the time. All that is then needed is for a ramp (usually on the vessel) to be lowered, bridging the gap between the ferry and the linkspan. The photos below show this process taking place at Oban (Scotland) as the Caledonian MacBrayne ferry Isle of Mull completed the docking process.
The linkspan is visible by the two white pillars on either side of the metal ramp.
In ports such as Dover "double deck" linkspans can be found where two decks of a large ferry can be loaded simultaneously.
[edit] See also
- Ferry slip (Barge slip)
