towed to the site and connected by high strength bolts or by post-tensioning 

 of epoxy-bonded joints .L J 



Many ship hulls of regular weight and lightweight reinforced concrete 

 were built in the United States in response to steel plate shortages during 

 World Wars I and II (about 15 ships in WWI and about 104 in WWII) . A few 

 reinforced concrete ships were built in Europe in each of the world wars. 

 These concrete ships saw service as tankers and dry cargo carriers J- ' J 

 Typical WWII sizes in the U. S. were 366-foot length, 54-foot beam, 35-foot 

 depth, and 11,000-ton displacement.L 9 J Concrete hulled lighters and barges 

 were also used. An experimental U. S. Navy landing ship of prestressed 

 concrete successfully performed many test landings on beaches in 1946 but 

 was not put into service. L J The concrete ships demonstrated good perfor- 

 mance particularly in resistance to vibration, fatigue, and abrasion, but 

 were uneconomic in the post-war periods, due, in part, to imitative designs 

 that did not utilize the advantages of concrete, and to high self-weight- 

 to-cargo-weight ratios . L 1 ° ' 1 U Commercially successful prestressed concrete 

 ocean-going barges (2,000-ton size) have been in regular service in the 

 Philipines for the past 9 years and have performed well.L ' J Reinforced 

 concrete ocean-going barges have been used in the U. S. Gulf states, 

 Mexico, South America, and Africa. L 1 iJ In 1962 a floating oil refinery was 

 built in Belgium on a two-way, post-tensioned, compartmentalized, concrete 

 barge about 180 feet long by 80 feet wide and was towed to Africa for 

 service there. A major reason for choosing concrete was concrete's 

 superior resistance to fire.L J 



A 3-year long program of detailed inspection (reported in 19 72) 

 of many USSR concrete floating dry docks found them to be, in general, in 



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