LNG: From Ship to Shore

Abstract

ABSTRACT An LNG (liquefied, natural gas) unloading terminal - the largest in the U.E and second only to one in Japan - has been designed by Raymond Technical Facilities Inc. (RayTech), for Columbia LNG Corp. and is nearing completion at Cove Point, Md., on the Chesapeake Bay. Tankers will be unloading Algerian ING at offshore berths from where it will be piped to shore, still as a liquid at -260 °F through a mile-long sunken-tube tunnel. This is the first such application of tunnel construction for carrying LNG. The original terminal design had provided for a conventional pile-supported trestle with pipeway and roadway from the offshore berths to the onshore storage and regasification plant. However, in view of the situation of the terminal in a relatively unspoiled, recreational area, and, particularly of the wetlands area with its value to the over-all local ecology, objections were raised by environmentalists resulting in the substitution of the tunnel for the more visible trestle. This concept entailed major changes throughout the project. However, once the change was judged worthwhile and economically tolerable by the owners, the work has proceeded as expected with the added attraction of the preservation of many acres of land as a wildlife refuge and recreational area. INTRODUCTION With depletion of oil and gas fields within the U.S. coming simultaneously with vastly increased energy demand, the importation of natural gas from foreign countries has become increasingly necessary. By liquefying the gas (by reducing its temperature to -260 °F and, thus, its volume to 1/600 of the original) and by the development of special ships for its importation into the U.S. from the oil and gas fields or Africa, the Middle East, Indonesia, Alaska, etc., a much needed new source of energy has been made available. Columbia LNG Corp., a subsidiary of the Columbia Gas System Inc., in 1970 started planning for LNG importation through a terminal second in size only to one already operating in Japan. The marine terminal and pipeline for the $30$ million complex at Cove Point, Md., will permit the unloading of the equivalent of a billion cu ft/D (28 million cu m) of natural gas imported from Arzew, Algeria. Raymond Technical Facilities Inc. (RayTech) a wholly owned subsidiary of Raymond International Inc., was first authorized by the owners in July 1970 to perform site investigations and to prepare preliminary designs and budget estimates of construction cost for the marine terminal to berth, unload, and service the new generation of 125,000 cu m ING tankers coming into use. RayTech was later committed to perform the final design including the preparation of working drawings, specifications, and bidding documents for all structures from the berth line to the contract limit interface, at the onshore tunnel shaft.