replaced by a manganese-steel pipe carried between armour-plate saddles and transoms 

 secured to manganese-steel piles. The work was done from a crib of tubular scaffolding, 

 which was moved on pontoons. 



190. ROADS, N., "How to Calculate Pipe Stress in Offshore Construction," Petroleum 

 Engineer, Oct. 1968, pp. D20-D23. 



191. ROGERS, W. M„ and DUCKWORTH, H. N., "Electronic Survey Helps Assure Integ- 

 rity of Offshore RpeUnes," Offshore Technology Conference, Vol. II, Apr.-May 1973, 

 pp. n299-n304. 



Keywords: Electronic survey device, Offshore pipeline 



Paper describes an electronic survey device which evaluates corrosion and mechanical 

 damage to offshore pipelines. The survey device is a self-contained unit consisting of a 

 power section, a transducer section, and a recording section; all three sections are connected 

 with universal joints. The unit travels tlirough the pipeline system, driven by the power 

 section winch has scraper cups to center the device in tlie pipeline and form a seal with the 

 pipe wall, so the survey device is carried through the pipeline by the liquid flowing tlirough 

 it. The transducer section uses a direct current electro-magnetic flux leakage technique to 

 detect defects on either pipe surface and provide signals to tlie recording section, where tlie 

 signals are stored on magnetic tape. As the survey device travels through the pipeline, it 

 records points of corrosion or damage, girth welds, valves, speed, and orientation of the 

 device. 



192. SANTI, G., "Trenching and Dredging in Deep Water," Ocean Industry, Vol. 6, No. 6, 

 June 1971, pp. 30-31. 



Keywords: Submersible cutter dredger 



A brief discussion of a manned submersible cutter dredger that has a working depth 

 capability of 200 feet is given. 



193. SCHWARTZ, H. I., "Hydraulic Trenching of Submarine Pipeline," Transportation 

 Engineering Journal, Proceedings Paper 8489, Vol. 97, No. TE4, Nov. 1971, 

 pp. 721-728. 



Keywords: Hydraulic trenching. Submarine pipeline 



The design, operation, and testing of a hydraulic trenching device designed to bury 

 large- diameter pipelines under varying conditions are discussed. 



194. SERPAS, L. B., BELAZONG, A., and MATTEELLI, R., "Selection of Routes for 

 Sub-Mediterranean Pipelines," Offshore Technology Conference, Vol. H, Apr.-May 

 1973, pp. n485-n503. 



Keywords: Mediterranean Sea, Pipeline routes 



Paper discusses the planning and procedure used in a marine survey to determine 

 feasible paths for pipeline routes across the Mediterranean Sea between North Africa and 

 Sicily. The techniques and instruments used in tlie surveying operations are described, which 



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