I have been having a very interesting discussion on ww2talk with member Steve G and several other interested parties about the possibility that the Germans may have either conducted, or have been planning to conduct, a commando raid against the Railway and or Road Bridges across Ports Creek. The subject arose when Steve was investigating a bomb or aerial mine that is believed to have hit nearby in 1940.
For those of you not in the know, Portsmouth is an island, divided from the mainland by a narrow strip of tidal sea water called Ports Creek. On the very north end of the island, butting up against the Hilsea Lines fortifications, was a Royal Army Ordnance Corps depot. Also nearby was Portsmouth Airport, where Airspeed – builders of the Oxford trainer and the Horsa Glider – had their main factory. In addition, the possibility of cripping Portsmouth Dockyard by cutting it off from the mainland must surely have tempted the German planners – particulary ahead of the possible German invasion in the summer of 1940.
Not only that, but it would have been possible to enter Ports Creek via Langstone Harbour. While Portsmouth Harbour was very heavily defended by an anti-submarine barrier and boat patrols, Langstone Harbour was much more vulnerable. It might have been possible to canoe up the Harbour in a similar manner to the Cockleshell Heroes raid on Bordeaux later in the war. Under cover of darkness and high tide frogmen could have swam to the piers of the road and rail bridges and set explosive charges on them.
According to something of a local legend, explosive charges were found nearby when work was begun on building the A27, which runs to the north of Ports Creek and has completely changed the area from its wartime appearance and geography. There remains a Second World War Pill Box near the Railway Bridge, facing south over the Creek, although when it was built we are not sure.
This is certainly the kind of operation that Major ‘Blondie’ Hasler would have approved of, and the Italians definitely had some capable frogmen as shown by their cripping of HMS Queen Elizabeth in 1942. But did the Germans possess the special forces to take on such a task? As far as I can tell, German Marines were an almost non-existent entity in 1940. Even so, it would have taken a considerable raid by the Luftwaffe to destroy the Bridges – and even then success could not be assured – whereas a couple of frogmen would have had a reasonable chance of crippling Portsmouth.
Did it happen? If not, could it have happened? Hopefully I can find out… unless anyone else out there can shed any light on this story?