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402 in Fig. 2. As described by its in- ventor, Maxwell Ballard, before a recent meeting of the North East Coast Institution of Engineers and Shipbuilders, the arch system is an innovation in the form of the upper structure, and it consists of strength- ened arch girder frames at regular intervals reinforcing the intermediate usual framing. Below the position of the normal molded depth there is no alteration in structure from the ordi- nary. .In lieu of the usual deck at this position with a bridge or shelter deck erection thereon, the structure consists of a transverse arch the up- per and lower abutments of which form the termination of the horizon- tal and vertical spans of flat structure of the deck and sides respectively. This gives a very rigid form of con- struction to resist the stresses im- posed on the vessel. By the frame head knees being arranged outside the framing and carrying the plating back, the deck area is maintained and the capacity of stowage improved. The arch deck height practically cor- responds to the bridge or shoulder deck height, and owing to this in- creased height of weather deck. the reverse shear which is moderate in amount does not bring the deck down to the highest point of the ordinary shear line on the forecastle front. At the extremities of the vessel fore- castle and poop erections are con- structed. Strength of the Vessel As regards strength the shearing stress over the cross section of the vessel is a maximum in the way of the neutral axis in the vicinity of the greatest shearing forces at the mid- dle of the fore and after bodies. The reduction in the arch type is about 20.8 per.cent. As regards reserve buoyancy the arch deck vessel is su- perior to the usual type of vessel and the increase in and better distribution of the reserve buoyancy are naturally beneficial to the stability of the de- sign. Under sea-going conditions it appears that there is distinctly less pitching than in vessels of the ordi- nary design, especially when the ves- sel is laden with a more or less homo- genous cargo such as coal. The roll- ing motion is most easy and for the timber trade as well as for coal trans- port this type of vessel appears to be most suitable. Comparing the arch type of con- struction with the ordinary vessel, owing to the economy in the distri- bution of the material in the arch type, whereby a large saving is. ef- fected, a smaller vessel is required to fulfil the same requirements as to THE MARINE REVIEW dead weight, and this involves a large reduction in cost of construction and capital outlay for the ship owner. The saving is effected not by the re- duction of scantlings, which are up to full rule requirements, but by the economical re-distribution of material whereby the whole elements of design are so affected as to permit of the re- duction in the dimensions. Moreover, there is a reduction in cost of pro- pulsion and maintenance both due to reduction in dimensions, the displace- ment being considerably less. It is claimed that the coal consumption works out some 5 per cent less for the same dead weight under power. Not only so, but a saving in weight is accompanied by an increase in the hold capacity which is a very consid- erable advantage especially in the November, 1913 mild steel horizontal multitubular boil- er constructed for a working pressure - of 120 lbs. per square inch. Powerful steam gear is provided for rapidly raising and closing hopper doors. During September, 101 vessels were built, of 30,864 gross tons, of which five were steel, of 17,033 gross tons, and 65 wooden, of 3,967 gross tons. The largest vessels in the lot were the Panaman, of the American-Ha- waiian Steamship Co.'s fleet, of 6,649 tons; the Santa Catalina, of the At- lantic & Pacific Steamship Co.'s fleet, of 6,309 tons; the Brilliant, of the Standard Oil Co.'s fleet, of 2,486 tons, and the yacht Cyprus, built for D. C. Jackling, of 1,037 tons. The steamer Keystorm, belonging to coal trade. About 2 to 2% cu. ft. per the fleet of the Keystone Transporta- Hf. oN \ \ To . \ 7 © . H , @ © 5 Way fey eee @ e i Sa ° 2 bi ye) BALLARD SYSTEM OF ARCH CONSTRUCTION ton increase is gained in underdeck capacity. Enough experience has been gained in this type of construc- tion, even though recently introduced, as to warrant the belief that both as regards economy in production and service, a most remarkable result has been obtained. Win. simmons & Co., Ltd, Ren- frew, launched last month, complete with all machinery on board and with steam up ready for trials, a 700-ton hopper steamer, being the fifth of a fleet of eight dredging vessels they have on hand for the naval port, Em- peror Peter the Great, now under construction at Reval by the imperial Russian government for warship pur- poses. The vessel is propelled by compound surface condensing marine engines, supplied with steam from a tion Co., which was wrecked near Kimeston, Ont., last year, is to be raised by the underwriters who have arranged with A. J. Lee, Westmount, Que., to undertake the work. Wreck- ers in general will be interested in this performance, as the job is a very difficult one, the steamer lying on Her side in- 102 ft. of water.. Com- pressed air is to be used to raise the vessel, and it is expected that as soon as she is buoyant she can be moved in about three lengths into compara- tively shallow water. Dock Commissioner R. A. C. Smith, of New York, has had plans prepared for a new dry dock capable of dock- ing the largest vessels in the world, and to be patterned after the immense Gladstone dock in Liverpool.