WW I German U-boat submarines sink France-bound US supply ships; German sailors on U-boat; torpedo wake; ship in IRIS; ship in IRIS explodes; Hog Island in Delaware River PANNED; world's largest shipyard PANNED; huge throng sees President Woodrow Wilson, Mrs. Wilson; Pres. waves; Mrs. Wilson breaks bottle on bow, ship slides; view from bow as flag-draped ship is launched;in NewHampshire shipyard view of wooden ships being built; dignitaries watch flag- draped wooden ship being launched; shipping director Charles Schwab boards ship CU; CU Schwab; view of freighter; 2nd freighter built of concrete; ship zooms along; CU saw cuts ship supports; various ships slide down ways into water; Hog Island shipyard dismantled; scaffolds fall; crane pulled over; half-demolished shipyard; very nice ship launchings