Chief Officer Weighs in on a Heavy Topic — the Anchor and Mooring Gear

Eurodam’s chief officer and Blog Board member Andre van Schoonhoven sent us some new photos and some very technical information on the ship’s anchor and mooring gear:

The mooring equipment is an important part of the ship’s equipment, since it’s used for tying up the ship in port, which is the whole idea of cruising. It also had to be finished before the float out, to tie the Eurodam up at the fitting-out pier.

The anchor-handling equipment is not yet completely finished. Below is a photo of the roller assembly, which still needs to be welded to the deck. The chain (or anchor cable) will roll over this, and it leads the cable from the hawse pipe (the pipe leading from the deck to the anchor housing in the hull) to the cable lifter (or gypsy). The gypsy is visible in the background and is driven by an electromotor. This is the same electromotor that drives the mooring winch next to it via an additional gear. That gear makes the gypsy turn slower than the winch, however, at much greater strength.

The roller assembly is in the foreground and the gypsy is in the background.

The mooring lines are also sometimes called hawsers. The interesting thing is that this is one of the first things that became regulated in the shipping industry under influence of the class societies. Being able to anchor and moor ships safely, even in extremely adverse weather conditions, enhances safety, and that directly influences the insurance premiums charged.

Holland America Line is a member of the Lloyd’s Register class society. Lloyd’s printed the first Register of Ships in 1764 to give underwriters and merchants information about the condition of the vessels they insured and chartered. The top classification of A1, from which the expression meaning first class or top of the line is derived, first appeared in the 1775-1776 edition of the Lloyd’s Register.

The chain locker where the anchor chain is stored and the hawse hole through which the chain is fed.

The numbers, weights and sizes of the anchors, chains and hawsers are regulated by the tonnage for equipment, as obtained from the following formulae:

Tonnage under upper deck equals LxBxDxC/100, with C representing the coefficient of displacement taken at 0.8 of the molded depth, with 0.75 as a maximum (basically, how much the shape of the hull varies from true block form). Addition for superstructures equals lxbxdx0.75/150.

Thus, the class society (Lloyd’s Register in our case) uses these equations to arrive at the Equipment Number. You then use the EN to look up in a table exactly the number, sizes and weights for anchors, chain and hawsers for a ship.

Traditionally ships were anchored using large hemp hawsers called cables. In 1836 the use of iron chains had become so common in the English merchant service and their superiority so well recognized, that the underwriters ceased to charge a higher insurance rate for vessels using iron chain. In 1840 side welding of chain was introduced in England, and from that time English chains of 1-7/8 inches and larger have been side welded.

Lloyd’s Register of Shipping augmented its rules in 1846 so that thereafter all chains of classed vessels were tested and stamped on each end to indicate load capacity. In 1853 Lloyd’s rules made it mandatory that, before a vessel could be classed, the test of the chain cable had to be certified, and in 1858 Lloyd’s issued rules regarding the length and size of chain cable. Lloyd’s progressively stiffened their rules regarding methods of manufacture and testing, resulting in the Anchors and Chain Cables Act of 1899, which with only a few amendments is still the basis of present-day testing procedures.

Something is missing from this picture ….

Some more historical dates about chain anchor cables:
1808: Wrought-iron cables are first recorded. They were made by Robert Flinn, a blacksmith, and used on the ship Ann & Isabella.
1813: Iron cables are recorded with other particulars of the ship.
1834: Lloyd’s Register rules state the length of cable to be supplied, but do not mention sizes or tests, however, they call for a reduced length for iron cables compared to hemp cables at a 6:7 ratio.
1846: Rules specify that cable must have been tested and have the test load stamped on it. The surveyors were to see the certificates.
1853: Certificates of test of chain cables are required to be produced prior to classification.
1856: The rules state that the length and condition of chain cables were to be ascertained by removal from the locker at each special survey.
1890: Lloyd’s Register rules sets a table of minimum weights for cables.