NON-SINKABLE SHIP

New Zealand Times, Volume XLIX, Issue 11252, 3 July 1922, Page 2

NON-SINKABLE SHIP

WELLINGTON lAN’S INGENUITY. CAPTAIN COL. MCDONALD’S INVENTIONAccording to the latest issue fd hand of the “Pacific Marine Review,” a remarkably ingenious design of a nonsd likable ship’s hull has been invented and; patented; by Captain Cel. McDonald, of Wellington, Marine Superintendent of the Union Steam Ship 00. The “Pacific Marino Review” publishes an illustration of Captain McDonald’s invention, which takes the form of a new cellular type of hull construction. The “'Review” states:—“lt is claimed for this design that the vessel can very handily 'be kept afloat with the entire bottom, removed. The designer deserves considerable credit -because he accomplishes this very desirable safety feature and at tlhe same time preserves the simplicity of construction so’as to add very little to the cost of building. ’Tween deck compartments and the hold tranks are so arranged that sufficient buoyancy with .adequate freeboard is available through the displacement of the ’tween deck compartments, even if the entire bottom should be cut off. The pamphlet describing this vessel gives complete specifications for a single soreiv steel steamer built on this principle for 8500 tons deadweight cargo capacity on -a mean draught 24ft Gin.

The scantlings for a hull built _ to these specifications would all bo sized to standard dimensions -and classification rules. Frames in way of ’tween deck spaces -are cut and bracketed to ensure a perfectly watertight job, so that with the ’tween deck compartments placed in the position shown on the inboard profile the vessel, would have ample buoyancy with the entire bottom -destroyed. All ventilators from the weather deck to lower holds have to he strongly constructed with standard deck scantlings and with tv watertight riveting job. The scuppers of the ’tween deck compartments loading to tlhe bilges of the ship are all fitter] on the cone system with caps controlled by screw rods from the weather deck. With a strong-ly-built watertight tunnel shaft and with ventilator for same built of heavy scantling and a good watertight jon, such a hull could navigate under its own steam with injuries to her bottom fore and aft which would absolutely sink the ordinary cargo-carrier. This construction of hull lends itself very readily to the rapid discharge of general cargo, on account of tlhe large uutuber of batches and t'ho posei'bility of working separate stevedore gangs in the ’tween deck compartments and in the held. It may also be readily adapted for longitudinal framing and for the carriage of crude oil and other biilk cargoes. Many designs, states the “Review” in conclusion, have been patented during the war .and since for making hulls safe after submarine attack or other injury. 111 large part these designs have 'been the works of minds entirely unfamiliar with sea conditions on the construction of vessels. Captain McDonald seems to have arrived at a very simple and efficient scheme for a practically unsink-able ship, and his idea is commended to the consideration of American naval architects.