48-CAR CAPACITY HYDROTRAIN rail barge was launched recently at Bethlehem Steel Corporation's San Francisco, (Calif.) shipyard. The barge is 400-feet long, 76-feet wide and 20-feet deep, and is one of the largest to be built in the Bay Area. Named Nikiski, the new barge is the fourth of five of this size being built by the yard and will operate between Seattle and Alaska. It is being constructed for the Harbor Tug & Barge Company, San Francisco, and will be operated by Puget Sound-Alaska Van Lines. The fifth barge, McKinley, will be launched in May.