Page 16: of Maritime Reporter Magazine (November 1977)

Improving Shipbuilding (continued from page 15)

ABS and to the Maritime Admin- istration.

The CG has proposed research, to be jointly funded with MarAd and implemented by the National

Shipbuilding Research Program, which would produce the stand- ard needed to establish perform- ance requirements. It would an- ticipate everything electric cable in ships must endure during con- struction, service, and when ex- posed to fire and flooding.

In addition, the CG has pro- posed a survey to list new and existing cable types; development of tests for determining if cable is acceptable in accordance with the performance standard, and evaluation of the performance standard by applying the tests to the cable listed; thus, a list of acceptable cable would be an end product.

The same four-task approach is already incorporated in recom- mendations resulting from re- search on the use of plastics in ships. They propose similar per- formance standards and tests for plastic pipe systems and for the epoxy chocks used to align ma- chinery. Usage in ships is now inhibited because what plastic pipe and chocks are expected to endure during installation and service has not been adequately described to polymer suppliers.

Thus, the suppliers have not suf- ficiently described the properties of their plastic products to per- mit design with the same assur- ances that exist from knowledge of metals.

The plastic research is disclos- ing facts which encourage more dialogue between polymer sup- pliers, regulators, owners and shipbuilders. Unlike steel, plastics are light in weight, do not rust "like hell" in seawater nor in cer- tain acids, are nonconductive but can be made conductive, are less energy intensive, and do not im- pose "in-process" problems with glare, fumes and noise.

Other research projects pro- posed, underway, and completed are also of significance to owners, regulators, designers and sup- pliers. These address multiplex- ing, rectangular vent-duct stand- ards, tank testing and photogram- metry. Multiplexing has not yet been started. The rectangular vent-duct standards, already pub- lished, improves productivity by identifying the minimum neces- sary components and sizes. It recognizes that many custom fit- tings and sizes were built to de- sign constraints which far exceed the accuracy of basic flow factors.

Tank testing research is cur- rently being implemented by

Southwest Research Institute.

The initial phase of photogram- metry, i.e., obtaining reliable in- formation about physical objects by measuring photographic im- ages, is completed. The report entitled "Photogrammetry in

Shipbuilding" was issued in July 1976 by the National Shipbuilding

Research Program. The technique is already in "solid" implementa- tion in shipbuilding for producing very accurate LNG tank sounding tables, and for predicting the fit of large ships and offshore plat- forms built in sections. The tank- sounding tables are clearly bene- ficial to regulators, owners and designers, but there are other applications, not in shipbuilding per se, that should attract their interests. Accurate measurements of bow waves or hull hogging and sagging are possible. The com- pleted research proved the fea- sibility of photogrammetrically acquiring accurate digital repre- sentations from scale models of ships' machinery spaces. Future research will disclose the relative costs for using the process to automatically plot pipe system arrangement and isometric draw- ings, and serve as the input "device" which would permit a combined pipe-systems designer,/ model maker to put his inherently interference-free piping arrange- ments into a computer. Thus, the future work by the researcher,

John F. Kenefick, Photogram-

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