Navy experiments with a diving bell - a new submarine life-saving device

Title Card: "Safety For Subs! San Diego - To avoid submarine disasters! In experimental rescue with new diving bell, Lieut. Momsen 'saves' S-4 crew." / MS New rescue bell being put in place / MS bell in water, Lieut. Charles Momsen on top of it, SOT he describes the bell's function: Wire is first attached to a submarine hatch by a diver. It was attached to a reel in the north part of the chamber. When this reel is round up, the bell is hauled down to the hatch of the submarine/ CU diagram shows how it works / INT submarine, rescuer coming out of bell from hatch, other sailors climb into bell through hatch / CU angle view of sailor going up ladder into bell / MS bell coming up to water surface / MC rescuer on boat by the ball, hatch of bell opens and sailors get into rescue boat / MS submarine surfacing water / Note: exact month/day not known