The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

‘s : fe 3 : z | SRNL eS es eS pe eA are ey June, 1915 There are four large main hatchways on the upper and shelter decks, and also auxiliary hatchways amidships, and at the after end. The wood hatch covers lie fore and aft and they are supported by transverse plate webs only. The masts are strength- ‘ened and fitted with outriggers to carry the double derricks at: each hatch. Nine powerful steam winches of Messrs. Clarks, Chapman & Co.’s latest type are installed for dealing with the loading and discharging of cargo. The vessel is fitted up with THE MARINE REVIEW wood shifting boards, feeders, etc. all to the requirements of the Board of Trade for the transport of bulk grain. The steam steering gear is by Messrs. Donkin. & Co.,. Ltd.; and ‘the ‘motor boat—somewhat of an innovation in the outfit of a tramp steamer— was built by Mr. Spain, ° of Sunderland, and it is fitted with a 7 barge horse- power engine supplied by the Page company, of Baltimore, Md. The accomodation for the officers and crew is upon a generous scale, each officer having a large single berth and the 4 | 207 crew has spacious quarters forward and arranged under the most sanitary conditions. The whole of the accom- modation is furnished with electric light supplied by Messrs. Clarke, Chapman & Co., Ltd. On the loaded trial trip the machinery fulfilled all the specified conditions to the satis- faction of the owners and_ their marine and engineering superintend- ent, D. B. Cumming, of Newcastle- on-Tyne, under whose _ supervision the hull and machinery were con- structed. Carriers An Analysis of the Line of Expected Development in the Near Future—Advantages of Various Systems TRUCTURAL~ development and S improvement in cargo vessel design resulting from the very varied requirements of international commerce are at present a notable feature of the ship building industry. Cargoes vary within the widest limits consequently a very great range of types are called for; thus steamers. suitable for the fruit trade, differ essentially from those carrying oil or wheat in bulk. Cargo vessels have hitherto been very generally constructed without longitudinal bracing, resulting in a latent weakness, which under normal conditions may not inter- fere with the successful working of the vessel; but which in case of emergency or exceptional stress may result in dis- aster. To mention an instance, the dis- aster to the Oklahoma, which was a vessel actually constructed with side stringers, but which under exceptional conditions’ was found wanting in strength to resist strains to which it was unexpectedly subjected. A stringerless vessel was from several points of view very convenient, in as much as _ there were no shelves for the lodgment of grain, coal or other bulk cargo, more- over the cost of construction was less. The result of experience has shown that the plating is. more vulnerable to damage between the frames, and the whole vessel is exposed to greater injury from broaching on collision. For small cargo vessels the corrugated sided type of construction has been found suc- cessful; it is one likely to be extensively adapted, as many advantages are claimed for it and it has successfully passed through a limited time test. It is stated by experts that the corrugations have the effect of improving the steering qualities of vessels, that the rolling and pitching in a seaway are appre- ciably reduced and that the speed is increased. There is moreover a gain in ‘ing its the deadweight capacity of an amount ” equal to the corrugations. Up to the present this method of construction has not been adopted in cargo vessels of large size or of high speed, so that it is not yet possible to state whether pro- portionate economies will be maintained irrespective of dimensions. Another interesting variety introduc- ing novel principles and ideas is the Ayre-Ballard, or arch principle of con- struction, consisting of a transverse arch over and above the normal hull and forming an integral part of the same. This form of construction enables pil- lars to be dispensed with, an advantage, as it enables a comparatively clear hold to be obtained. This type would appear to be mainly suitable for single deck vessels, so far steamers of large size have not been constructed in accordance with the arch principle. There are opportunities open both for the engineer and the capitalist; the last word in ship construction may not be heard for generations. Who a generation back could have foreseen a vessel without funnels driven by power? The principle of longitudinal fram- ing has many convinced advocates urg- advantages and advising its adoption. A comparison between two vessels, one constructed with longi- tudinal frames and one without illus- trates the strong points of the former. In the case of two vessels of identical dimensions, one with longitudinal fram- ing and one without (the dimensions being, length 399 feet, breadth 51 feet molded, by 28 feet 314 inches molded, a deadweight carrying capacity of 8,000 tons and draught of 24 feet) then the one with the framing has an increased deadweight capacity of 200 tons, equal to 2% per cent of the deadweight capacity of the ordinary vessel, together with a longitudinal strength of 15 per By Thomas Osborne cent in excess of that built on the ordi- nary transverse system; both vessels being single-decked. Other advantages are claimed, which would require a special article to describe in detail. An important point of difference is that the floor of the vessel is carried out flat to the side of the vessel instead of peak- ing the bilge brackets as is customary in vessels of ordinary construction. It is claimed that the flat floor gives an increase in cubic capacity and that the absence of beam knees results in an increase in the capacity for storing bale goods. Experienced ship designers state that in vessels engaged exclusively in the lumber trade, the loss in capacity can be neutralized by building vessels broader or longer than usual. To quote an actual experience, in one case where an order was given for a lumber ship of 16,500 tons deadweight, with the same internal capacity for long timber ‘as the transversely built ship, it was found that an increase on the original dimensions of 15 feet in length gave an increase in deadweight of 900 tons, with the use of 200 tons less steel than would be required in an ordinary vessel of smaller dimensions. Some experts have raised an objection to the longitudinal. frame principle, that the longitudinal formed shelves on which coal, grain or other bulk cargo could lodge, but that may be answered by the fact that these frames in a vessel of 8,000 tons dead- weight would only accommodate four tons in that way, which could be readily swept off, as the longitudinals them- selves formed ladders up the sides of the ship. Moreover this system has been found to be better suited for ven- tilation and it rendered the hull practi- cally free from vibration. It also facili- tates expeditious cleaning and opens up the possibility of successfully increasing the length of a given vessel while still