Show TROUBLE TROUBLEs ON SUB FACES NAVY PROBE MARE ISLAND NAVY YARD Cal April 13 INS INS Although Although naval officials minimized possibility of sabotage an official naval board of inquiry will convene here shortly to o investigate f trouble reportedly of a serious nature which developed during the shake-down shake cruise of the new submarine Pompano During a week six-week maiden cruise to Panama the submarine shook so hard a door fell off according to sailors aboard her However navy officers said the trouble was confined to one of the four engines The submersible constructed constructed constructed con con- here was the fourth of six sister submarines built under the navys navy's 1935 construction program She was launched March 11 |