Page 4: of Maritime Reporter Magazine (February 1973)

The General Dynamics Quincy Shipbuilding Division will build the three LNG ships for Cryogenic Energy Transport,

Inc., Liquegas Transport, Inc., and LNG Transport, Inc., at a total cost of $268.7 million. General Dynamics awarded a $40-million contract to Pittsburgh-Des Moines Steel for the construction of the 15 tanks for the three LNG ships.

LNG Ships-A New Construction Approach

U.S. Shipyard And Cryogenic Tank Builder Team Up

To Offer An Improved Method Of LNG Ship Construction

Fred E. Hamren Jr.*

At present, the largest LNG car- rier in service has a capacity of 75,000 cubic meters of liquefied natural gas. Ships of 125,000 cubic meters are under construction, with larger sizes on the drawing boards.

Construction methods for these ships, whether they use the mem- brane or free-standing container design, generally utilize a standard shipbuilding approach, i.e., the ship's hull and LNG containers are both built and integrated at the same shipyard.

The Quincy Shipbuilding Divi- sion of General Dynamics Corpora- tion, one of the largest U.S. ship- yards, will construct its newly or- dered 125,000 - cubic - meter LNG ships utilizing LNG tanks pre- built at a remote site by an experi- enced cryogenic tank manufactur- ing company. Its prime subcontrac- tor in this plan is Pittsburgh-Des

Moines Steel Company, a leading builder of land-based LNG storage tanks.

This order for 15 large storage tanks for three 125,000-cubic-meter

LNG ships constitutes not only the first major order for the large ca- pacity LNG ships from U.S. ship- yards, but also the first use of a traditional tank fabricator to con- struct the required cryogenic tanks of this type away from the ship- yard for later insertion in the hull.

PDM was picked by General Dy- namics for this role as ship tank builder, based on PDM's acknowl- edged position as one of the lead- ing fabricators in the USA, and as a result of their proposal which was chosen by General Dynamics from among other U.S. fabricators after a long period of competition. PDM received a contract for $40 million for the 15 tanks for the three LNG ships.

PDM is a large, independent, en- gineering and construction organ- ization with more than 80 years' experience in designing and build- ing major metal structures. Utiliz- ing 15 plants nationwide and li- censees throughout the world, PDM has engineered, fabricated and erected specialized metal struc- tures, including the world's larg- est supersonic wind tunnel, en- vironment simulation systems for outer space, habitats for the ocean depths, nuclear containment ves- sels, and storage facilities for most commercially storable gases and liquids.

PDM has been a leader in the field of liquefied natural gas stor- age and process facilities from the beginning. This leadership has al- lowed them, over the years, to be- come intimately familiar with all facets of this field, from construc- tion of some of the largest LNG (Continued on next page) *Fred E. Hamren Jr. is manager of sales,

Systems Group, Pittsburgh-Des Moines

Steel Company, Neville Island, Pitts- burgh, Pa. 15225. Figure 2—The proposed manufacturing plant with separate areas for the forming and trimming of plates, subassembly of sphere sections and final assembly. At the plant, the spheres will be loaded onto the barges without the use of lifting equipment.

Maritime Reporter/Engineering News 6