Thought to be Selected Originals from late 1940s material.

Heligoland, off Germany.

The U. Boat pens, gun emplacements and defences on the German island of Heligoland are blown up by the British Navy.

LS View of Heligoland from the sea before the explosions.

CU exterior and interior views of U Boat submarine pens and gun emplacements.

CU Lieutenant Commander Frank Graves presses the button setting off the fuses, on the 4th pip of the BBC 1 o'clock time signal.

LS CU The explosion from sea level.

CU a pilot in a plane flying overhead signals OK.

LS Aerial view of the explosion. Smoke rises.

Possibly connected with 47/33 - MD.