In 1913 a further load line committee was appointed and reported in 1915, but the war delayed any action, and in 1927 another committee was asked to reconsider the whole problem, and in addition to examine (a) the practice of various countries which permitted vessels carrying wood cargoes to load deeper, and (b) the contention of the United States that oil tankers (vessels carrying entire cargoes of oil) could with safety be loaded deeper than ordinary ships. This committee is still sitting, and has before it a suggested departure in principle, viz. :—to allow vessels which carry whole cargoes of timber and oil to be loaded deeper than other ships.
The detailed calculations to ascertain the freeboard of a vessel are necessarily complex and can only be undertaken by an expert.
In order however to give an idea of the actual amount of free board it may be taken roughly that for a cargo vessel having a forecastle, a bridge and a poop the freeboard will be about one quarter of the depth of the ship from the keel to the uppermost continuous deck.
(b) Passenger Ships.—The question of additional protection of passenger ships arose from a committee which in 1887 was considering the regulations for boats and life-saving appliances on British vessels; Thomas Gray, the official then in charge of the Marine Department of the Board of Trade, suggested that a proper arrangement of internal partitions ("bulkheads") should be pro vided in order that the vessel might remain afloat for a reasonable length of time to enable the life-saving appliances to be used. The Bulkhead Committee of 1890 suggested rules for the number and position of bulkheads, which permitted a reduction in the amount of life-saving appliances. The conclusions of this committee deter mined the practice until 1911, when the Merchant Shipping ad visory committee suggested that the question of life-saving appliances needed adjustment. Following the loss of the "Titanic" in April 1912 a Bulkhead Committee was appointed to consider the whole question, but after the Court of Enquiry presided over by Lord Mersey, the question of subdivision was separated from that of life-saving appliances. Consequently for the first time regulations were prepared for the number and position of bulk heads (subdivision). It was laid down that passenger vessels should have as efficient a scheme of subdivision as the nature of their service or their trade would allow. It was realized that regu lations which destroyed the economic possibilities of trade were worse than useless.
While this committee was sitting an international conference was held in London to consider the whole question of safety of life at sea—embracing subdivision, life-saving appliances, wireless and navigation. The general lines of agreement were embodied in a convention signed by all the principal maritime nations (save Japan) in March 1914—and adopted by parliament in Great Britain and some other countries; but it was only made partially operative on account of the World War. As in certain respects the
subdivision regulations were incomplete, the British Government only put into operation the minimum requirements and applied these to all passenger vessels which carried more than 12 pas sengers. When however during the war the provisions of the con vention were examined in regard to new ships, it was rapidly found that such drastic alterations were required to vessels carrying a relatively small number of passengers as to render them econom ically impossible.
The whole question has been re-examined both by Governments and by the International Chamber of Shipping, and as a result the question of revising the whole convention was under consideration in 1928. It has been generally recognized that while the regula tions laid down in 1913-14 might be deemed to apply to vessels almost wholly devoted to passengers, such as the large liners on the North Atlantic, yet considerable alterations are necessary to apply them to all other passenger ships.
Any system of subdivision must take into account— (a) the spring of (i.e., distance between) bulkheads—the more passengers carried the closer is the spacing; (b) the height of the bulkheads above water—the greater the height, the wider is the spacing; (c) the strength of the bulkheads in relation to the height of water which may be behind them when an adjacent space is full of water ; (d) the probable contents of the various parts of the vessel— some spaces requiring more water to fill them than others, and (e) the nature of the damage to the side and underwater por tion of the ship ; it should be observed that it is of little use providing bulkheads unless the ship can remain afloat with the space between them open to the sea, and that where any greater protection is necessary endeavour should be made to arrange that the vessel will float with an intermediate bulkhead damaged and the space open to the sea.
Lloyd's Register of Shipping and the other classification societies have rules for the number of bulkheads in cargo vessels. A bulk head is required near the bow called the collision bulkhead, one has to be fitted at each end of the machinery space, and another near the stern. In general, while all ships have 4 bulkheads, yet when the length exceeds 285 ft., more bulkheads are required on the scale of one bulkhead for about every 65 ft. increase in length; thus a vessel 285 ft. long should have 5 bulkheads, and one 610 ft. long io bulkheads. The result of the suggested amendments to the convention would be that with a small number of passengers there would be the same number of bulkheads as required by Lloyd's rules, but these bulkheads would have to be spaced in accordance with the principles given above. (W. S. A.)