‘DWI’ Wellington bomber

Following Italy’s coming off the fence her vessels joined German ones in being denied access to Suez. Japanese merchantmen continued to cause headaches for the Canal authorities, being allowed to ply the waterway right up until the outbreak of war in the Far East. They received close attention. Armed guards were placed on board them which, even if they could not prevent a deliberate scuttling, might succeed in preventing a ship being manoeuvred into a blocking position. To guard against a covert approach from the south, aircraft reconnoitred the area between Port Said and Shadwan Island in the Red Sea, a distance of 160 miles. Ships approaching Port Said were boarded by an examination service. Those allowed to pass received a special signal, which was constantly changed and known only to a select few. Vessels proceeding without authority were first to be warned by a shot across their bows and ‘if this is not instantly obeyed, ship is to be sunk by gunfire’. The same procedure was followed at Port Tewfik with the additional safeguard of a boomship across its harbour from sunset to sunrise in view of the southern end’s vulnerability to serious blockage. Examination officers were under instructions to look out for specially fitted ships able to lay mines by tube or drop them overboard from an aperture across the water. These measures worked extremely well, with not one instance of an attempt to sabotage the Canal being reported.

Where Canal defences were most vulnerable, as the Air Staff forecast, was to aerial attack. All the more so because, at this early stage of the conflict, anti-aircraft resources were scarce, the majority of what was available being deployed at Alexandria, Cairo and in the Western Desert. Even six months after Italy entered the fray there were still no anti-aircraft defences between the terminal ports. The Regia Aeronautica mounted air raids against Port Said (which lacked searchlights) and Port Suez in September. Its bombing proved wildly inaccurate, not least because bombs were released from great heights. Vice-Admiral Pipon, the Senior British Naval Officer Port Said, was nevertheless alarmed that enemy aircraft were able to fly over the Canal with impunity at night. To deny them targets he ordered that no ships were to be present throughout hours of darkness. Pipon’s concern was heightened by his realisation of the enhanced importance of Suez:

The Canal itself appears to me absolutely vital to the military war effort in that, should it be blocked, neither Port Said, Alexandria, Malta, Haifa, Crete or Greece could receive the necessary reinforcements and supplies without their being sent from Suez to another port by inland transport, which I understand is already much overworked. The disembarkation at Suez and re-embarkation at a Mediterranean port would also be a cause of grave delay.

Royal Air Force Middle East responded complacently that the Italians were unlikely to mount heavy air raids against Suez. Thus far, solitary aircraft or small formations had been involved; a policy that looked set to continue given that ‘the Italians are reluctant to use flares, probably for fear of giving away their positions’. Only at the end of its missive, and parenthetically, was there any recognition that German aircraft might soon participate. At the start of the Mediterranean war, minesweepers were in short supply. This had led, late in May 1940, to the dispatch from Britain of three ‘DWI’ Wellington bombers, converted to act as minesweeping aircraft through adding a ‘hoop’ and magnetic field generator. After flying across France, they arrived for the outbreak of war and could cover the whole length of the Canal. As it happened, the Italians lacked air-laid magnetic mines and their threat would not materialise until Nazi Germany turned its attention to attacking Suez. On the night of 18–19 January 1941 Luftwaffe bombers duly arrived, beginning the most dangerous period for the defence of Suez.