If there is no 'alongside' berth or mooring available, a ship or craft will have to depend on its own anchors. The following types of anchor are in most common use today:
CQR (Chatham Quick Release), or Plough This is now the standard anchor in most yachts and small craft. It will be found in some SCC MFV's. |
Danforth This is the type used in Royalist and is particularly effective for its size and weight. |
Admiralty Pattern (or Fisherman's) Normally used in MFV's, boats and small craft. It is the most cumbersome to stow. |
Bower The largest anchor that a ship uses. It is stowed in a hawsepipe. |
The Bower Anchor and How it Holds
A ship cannot anchor where the water is too deep. It is not just a question of whether the cable is long enough to reach the bottom; it is important to remember that the anchor is designed:
- To hook firmly into the sea-bed when the cable is pulling straight along the ground from the anchor;
- To break out of the ground easily when the cable is pulling from above.
The anchor will hold only so long as the part of the cable nearest to it is lying along the bottom, exerting a horizontal pull. The more cable a ship has out, the less likely she is to drag. The amount of cable used by a ship when anchoring is normally at least four times the depth of water.
Cable construction varies from chain, in the case of ships, down to cordage in the case of small boats. Chain cable is normally made of forged steel or wrought iron. In all chain cable except the smallest, the links are studded to prevent kinking. The size of cable is measured by the diameter of the metal forming a link.
Cable is supplied in lengths of a shackle, which is 27.5 metres long. In HM Ships, shackles of cable are joined by means of joining shackles. The anchor is secured to the outboard end of the cable by means of an anchor shackle.