Reports of an attack on Constantinople harbour

Under the date of 1 August 1915 British chronologies of the war recorded a British submarine forcing its way into the harbour of Constantinople. A chronicle published in 1918 under the auspices of the British Ministry of Information went even further and stated that submarines had blown up the Galata Bridge over the Golden Horn. No such attack, however, is confirmed by later, more accurate sources: neither by Julian Corbett’s British official history of naval operations, nor by the memoirs of Commodore Roger Keyes, chief of staff of the fleet at the Dardanelles, nor by Turkish studies. The pontoon Galata Bridge, built in 1912, survived the war and remained in use until 1992.

At the turn of July and August only one British submarine was operating in the Sea of Marmara: E14 under Lieutenant-Commander Edward Boyle. It was already his third patrol beyond the straits. He set out on 21 July. In the Narrows he fouled the mooring cable of a mine, and off Nagara Point he saw a new obstacle: a net slung beneath a line of barges. He passed under it at a depth of about 24 metres. The next day he met E7 at sea, which was finishing her patrol, and warned her commander about the net. From 24 July Boyle remained alone in the Sea of Marmara.

There was little booty. Steamers had almost disappeared from the sea, and the only larger ships that showed themselves sailed as hospital ships, under the sign of the Red Crescent. Boyle therefore sank sailing vessels that ventured out from under the cover of the shore batteries, and torpedoed only one small steamer, lying at the pier at Rodosto. From the master of one of the sunken sailing vessels the British heard that troops now travelled by rail to Rodosto and from there marched on foot for three days and nights to Gallipoli. Supplies for the peninsula were carried at night along the coast, in sailing vessels and barges escorted by destroyers.

British submarines had already penetrated the harbour of Constantinople itself at least twice. On 25 May E11 under Lieutenant-Commander Martin Nasmith torpedoed the transport Stamboul at the arsenal quay. On 15 July E7 under Lieutenant-Commander Archibald Cochrane entered the harbour submerged and fired a torpedo towards the ships at the arsenal. According to Turkish records it hit the quay. At night Cochrane surfaced and shelled the powder works at Zeytinburnu in the western suburbs of the city, and two days later he blocked with gunfire the railway line along the Gulf of İzmit and blew up the ammunition wagons of a train. It is not known where the date of 1 August in the chronologies came from. Possibly they recorded, late and with exaggeration, news of these raids that reached the press by a roundabout route.

The expeditions into the Sea of Marmara were becoming ever more dangerous. At the end of July, on 26 or 27 July according to different sources, the French submarine Mariotte, which was to join Boyle, got stuck in the Narrows, most probably in the new net. She surfaced a few hundred metres from the battery at Çanakkale, and her crew, under fire, scuttled her and were taken prisoner. Even so, the British were preparing further patrols. The great offensive on Gallipoli was approaching, and on 5 August Nasmith’s E11 returned to the Sea of Marmara to cut, together with E14, the routes by which the Turks were sending reinforcements to the peninsula.