Infrastructure of a Modern Shipyard

Pre-fabrication involves assembling components of a structure in a manufacturing site and then transporting those parts to the construction or building site (in this case a shipyard).

A good example was in play during the construction of the BC Spirit Class Ferries. The hulls were built in North Vancouver and then towed to Victoria where the Yarrows shipyard built and subsequently installed all the superstructure (everything above the main deck).

Shipyards today will construct a vessel using components that are constructed both off and on-site. The onsite work will involve specialized areas and equipment. The off-site work involves pre-fabrication.

Modern shipbuilding makes considerable use of pre-fabricated sections. Entire multi-deck segments of the hull or superstructure will be built elsewhere in the yard, transported to the building dock or slipway, and then lifted into place. This technique is also known as "block construction".

The most modern shipyards pre-install equipment, pipes, electrical cables, and any other components within the blocks, to minimize the effort needed to assemble or install components deep within the hull once it is welded together.

On-site Infrastructure

The different kinds of specialized work that take place at a shipyard are supported by an extensive infrastructure of equipment, buildings, and technologies.

Cranes

A crane is a type of machine, generally equipped with a hoist, wire ropes, or chains, that can be used both to lift and lower materials and move them horizontally. Many different types of cranes are found in shipyards. There are enormous cranes capable of lifting tens of thousands of pounds that travel on designated tracks alongside the dry dock, or to and from work sites. Then there are smaller more mobile cranes that can be transported on the back of trucks. Some cranes are fixed to walls and are only used to move specific items on-and- off shelves or benches. Other cranes have pipe frameworks and rubber tires and can be used to move everything from small parts or even to cradle boats coming out of the water. The cranes utilized in building new ship modules, or blocks, must be capable of lifting hundreds of tons to facilitate the assembly of a new ship.

Slipways

Slipways vary in size: large slipways can be used to build and repair ships and boats, while smaller public slipways can be used to launch recreational vessels.

The nautical term 'ways' is an alternative name for slipway. A ship undergoing construction in a shipyard is said to be 'on the ways'. If a ship is scrapped there, she is said to be 'broken up in the ways'.

Drydock/ Graving Dock

A drydock is a narrow basin that is flooded to allow a ship to be floated in, and then drained to allow the ship to come to rest on a dry platform. Drydocks are used for the construction, maintenance, and repair of ships and boats. There are different kinds of drydocks that vary depending on the size of the ship, the kind of work that needs to be done, the proximity to the water, and the tidal range.

Graving Dock

The traditional form of drydock, commonly known as a graving dock, is a narrow basin made of earthen berms and concrete into which a vessel may be floated. When the water is pumped out the vessel is supported on blocks for inspection or repair. When the work on the ship is finished, water is allowed to re-enter the dry dock and the ship is refloated.

The Esquimalt Graving Dock owned, operated and maintained by the Canadian federal government is the largest solid-bottom commercial drydock on the West Coast of the Americas. The dock can accomodate about 90% of the world's ships including vessels up to 100,000 dead weight tonnage (DWT). Follow this link to find out more about the Esquimalt Graving Dock.

Floating Drydock

These drydocks are massive floating platforms that contain buoyancy tanks. The tanks can be filled with water and as the platform slowly submerges, ships can be winched over pre-set docking blocks. Once the ship is precisely positioned and secured, the drydock caisson is closed. The water trapped in the drydock is pumped out along with water in the buoyancy tanks and the ship and platform slowly rise out of the water until they are at a heightened, safe working level.

A typical floating drydock involves multiple sections of different dimensions that can be constructed to accommodate ships of different sizes. The advantage of floating drydocks is that they are transportable.

Syncrolifts

Syncrolifts are systems of synchronized winches used for lifting boats and ships out of the water. A vessel is maneuvered over a submerged cradle, which is then lifted by a set of synchronized hoists or winches. The vessel can be worked on in place, or moved to a different worksite, so the Synchrolift can be freed for other purposes. Syncrolifts are often linked to a rail system to transport cradles across a shipyard. The largest syncrolifts can lift vessels up to 100,000 tons, and can facilitate the work on more than one vessel at a time. Because of this capacity, syncrolifts are increasingly replacing older dry dock systems.