Belfast, Northern Ireland, United Kingdom — Northwestern Europe (the British Isles)
Caisson
The caisson is a hollow gate which closed off the entrance to the dock. Shaped like a ship's hull, it is made of wrought iron and hollow inside.
When filled with water it sank down into grooves at the entrance to the dock, so sealing it. When the dock was closed off, it was possible to cross the dock by walking along the wooden deck on top of the caisson. When it was pumped empty by a stream pump, it became buoyant and floated up to allow the ship to be drawn in and tugged out of the dock. Constructed in 1867, it is one of the oldest surviving vessels made by Harland and Wolff. It was launched by the firm in the same way as a ship and was designated 'Hull No. 50' on their shipping list.
[Photo captions]
Above, left The plan shows the caisson's interior lattice-like supporting framework. The handrail that ran along the top of the caisson is also detailed.
Left The plan shows how the gate fitted into the dock in cross-section
Far left This plaque is located on the opposite side of the caisson, and is visible from the other side of the dock
Above The caisson in place at Alexandra Dock was of a similar 'ship-like' design
[Balloon caption on this photo reads] The caisson has a very similar structure to a ship's hull, and was assembled in the same way. It was even given a hull number in sequence with all the other vessels Harland and Wolff built.
Topics. This historical marker is listed in this topic list: Waterways & Vessels. A significant historical year for this entry is 1867.
Location. 54° 36.409′ N, 5° 54.648′ W. Marker is in Belfast, Northern Ireland. Marker is on Queens Road, on the left when traveling north. Part of the Titanic Belfast complex. Touch for map. Marker is at or near this postal address: Hamilton Dock, Belfast, Northern Ireland BT3 9DT, United Kingdom. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. 1908 Harland and Wolff Shipyard (within shouting distance of this marker); The Bridge Deck (within shouting distance of this marker); First Port: Views of Belfast (within shouting distance of this marker); On Board SS Nomadic (within shouting distance of this marker); Hamilton Dock: Refurbishment and Restoration (within shouting distance of this marker); The Dockside: A Hive of Activity (within shouting distance of this marker); Bigger Ships and Bigger Docks (within shouting distance of this marker); Keel Blocks (within shouting distance of this marker). Touch for a list and map of all markers in Belfast.
Also see . . . The Hamilton Graving Dock. (Submitted on June 13, 2019, by William Fischer, Jr. of Scranton, Pennsylvania.)
Credits. This page was last revised on September 7, 2022. It was originally submitted on June 13, 2019, by William Fischer, Jr. of Scranton, Pennsylvania. This page has been viewed 267 times since then and 49 times this year. Photos: 1, 2, 3. submitted on June 13, 2019, by William Fischer, Jr. of Scranton, Pennsylvania.