Truth surfaces at last about plan for submarine pens in Rock of Gibraltar

BRITISH military chiefs planned to build submarine shelters inside the Rock of Gibraltar during the Second World War, according to a historian.

Ian Reyes found plans indicating two possible sites for bombproof underground berths and documents noting a positive response from the British Admiralty. The discovery confirms as true a decades-old rumour that had been largely dismissed as a flight of fancy more befitting a Hollywood action movie.

The documents, published this week by the Gibraltar Chronicle, show that detailed plans were drawn up in 1942 to construct subterranean submarine pens to enable the vessels to refuel and rearm in safety. “The idea of these submarine tunnels has always been there, an old tale told mostly by Gibraltar taxi drivers. Now it turns out it was true all along,” said Mr Reyes, who found the plans in a file marked “submarine plans” in the National Archives in Kew. “There were also other schemes for over-ground shelters,” he said, adding that the underground pens would have been connected to existing strategic military tunnels within the peninsula.

The Nazis had shown the advantages of protecting submarines from aerial attack by constructing U-boat pens, or bunkers, at German ports and across occupied Europe soon after hostilities broke out.

At the time the plans were being drawn up by the civil engineer in chief ’s department, submarines operating from Gibraltar had to moor alongside Royal Navy ships to resupply, exposing them to aerial attack and sabotage.

Italian frogmen based across the border in Spain, which helped the Axis cause despite officially remaining neutral, used manned torpedoes to attack the Bay of Gibraltar at night.

The technical drawings reveal that berths housing between four and six submarines, carved into the Rock, would have been protected by reinforced concrete and breakwaters aimed at foiling any attempted attack.

The two locations considered for the underground base were on the west and the east side of Gibraltar, with the latter gaining wider approval as it was seen as being “practically immune” to potential fire from Spanish territory in the event of a siege.

The Nazi regime drew up plans in 1940 for a military operation to take Gibraltar, codenamed Operation Felix, but it was never mounted due, in large part, to the reluctance of General Francisco Franco, the Spanish leader, to enter the war.

Plans to build the submarine pens were eventually discarded owing to the success of Operation Torch, the Allied operation to seize control of North Africa in November 1942, which substantially reduced the risk of British vessels moored at Gibraltar being bombed.