'EM' (ii) was a British naval undertaking to ensure the passage of the PQ.18 convoy with Lend-Lease matériel to the ports of the northern USSR (2/21 September 1942).

The convoy departed Loch Ewe on the west coast of Scotland on 2 September 1942 and reached Arkhangyel’sk on 21 September 1942. Following the disaster of the preceding PQ.17, the British were determined to provide the convoy with air cover, in this instance through the incorporation in the escort force of the new escort carrier Avenger, recently arrived from construction in the USA.

Postponed because a large part of the Royal Navy was engaged in the 'Pedestal' convoy operation in the Mediterranean during August, this major convoy was based on 38 ships (15 British including the oilers Black Ranger, Grey Ranger and Oligarch, and the rescue ship Copeland, 20 US and three Panamanian) which departed Loch Ewe for Iceland, where three remained and from which another eight (six Soviet and two US) joined.

Under the command of Rear Admiral R. L. Burnett, the escort comprised a 'carrier force' (the escort carrier Avenger with 10 Hawker Sea Hurricane single-engined fighters and three Fairey Swordfish single-engined anti-submarine aircraft, and the destroyers Achates and Malcolm), and the 'fighting destroyer escort' (the light anti-aircraft cruiser Scylla and the destroyers Onslow, Onslaught, Opportune, Offa, Ashanti, Eskimo, Somali and Tartar constituting Force 'A', and destroyers Milne, Marne, Martin, Meteor, Faulknor, Fury, Impulsive and Intrepid constituting Force 'B').

Close escort was provided by the auxiliary anti-aircraft 'gunships' Alynbank and Ulster Queen, the corvettes Bergamot, Bryony, Bluebell and Camellia, the anti-submarine trawlers Cape Argona, Cape Mariato, Daneman and St Kenan, and the minesweepers Gleaner, Harrier and Sharpshooter.

More distant cover was provided by Vice Admiral S. S. Bonham-Carter’s 'cruiser covering force' (the heavy cruisers Norfolk, Suffolk and London) and Vice Admiral Sir Bruce Fraser’s 'distant covering force' (the battleships Anson and Duke of York, the light cruiser Jamaica and the destroyers Bramham, Broke, Campbell, Keppel, Mackay and Montrose).

Two other elements of the British operation were the heavy cruiser Cumberland, the light cruiser Sheffield and the destroyers Amazon, Bulldog, Cowdray, Echo, Eclipse, Oakley, Venomous, Windsor and Worcester carrying reinforcements and stores to Spitsbergen, where they waited in case they were needed to support 'EM' (ii), and the submarines Shakespeare, Sturgeon (returned to port with mechanical problems), Tigris, Tribune, Unique, Unrivalled, Unshaken and Free Norwegian Uredd patrolling off northern Norway (three) and the Lofoten islands group (four), as well as the Free French Rubis.

A combined RAF and RAAF detachment, made up of 32 Handley Page Hampden twin-engined torpedo bombers of Nos 144 and 455 Squadrons, nine Consolidated Catalina twin-engined maritime patrol flying boats of No. 210 Squadron and three Supermarine Spitfire single-engined photo-reconnaissance aircraft, was sent to the air base at Vaenga in the northern part of the USSR to fend off any attack by the German battleship Tirpitz that might develop. Nine Hampden aircraft were lost en route to the USSR, one of these crash-landing in German-occupied Norway and yielding the Germans a plan for the operation.

On 9 September the Kriegsmarine despatched an interception force under the command of Vizeadmiral Oskar Kummetz: this comprised the 'pocket battleship' Admiral Scheer, the heavy cruiser Admiral Hipper, the light cruiser Köln and the destroyers Richard Beitzen, Z-23, Z-27, Z-29 and Z-30 of Kapitän Gottfried Pönitz’s 8^th Zerstörer-Flottille. The surface ships were soon recalled when the strength of the British escort and covering forces was appreciated. Also at sea was a force of 12 U-boats in the form of U-88, U-225, U-377, U-378, U-403, U-405, U-408, U-435, U-457, U-589, U-592 and U-703.

In the event the Luftwaffe proved a formidable opponent with, among others, 42 Heinkel He 111 twin-engined torpedo bombers of Oberst Martin Harlinghausen’s Kampfgeschwader 26 and 35 Junkers Ju 88 twin-engined dive-bombers, which had practised simultaneous attacks to swamp the defence with high- and low-level attacks.

As the convoy started to move to the north and then to the east, it was shadowed and reported by U-boats, but Kapitänleutnant Heino Bohmann’s U-88 was sunk by Faulknor off Spitsbergen. The convoy was sighted by a Blohm & Voss Bv 138 three-engined reconnaissance flying boat on 12 September, and later on that same day level bombers of Oberstleutnant Erich Bloedorn’s KG 30 and torpedo bombers of Major Werner Klümper’s I/KG 26 and elements of Major K. Lersche’s III/KG 26 sank the 5,432-ton US Wacosta, 4,826-ton US Oregonian, 4,885-ton Panamanian Macbeth, 5,441-ton Panamanian Afrikander, 6,209-ton British Empire Stevenson, 7,044-ton British Empire Beaumont, 3,124-ton Soviet Sukhona and 7,177-ton US John Penn II.

On 13 September Korvettenkapitän Reinhard von Hymmen’s U-408 sank the 7,191-ton US Oliver Ellsworth and 3,559-ton Soviet Stalingrad.

On 13/14 September, Sea Hurricane fighters launched from the escort carrier Avenger shot down five German aircraft, though four Sea Hurricane machines were lost, three of them to 'friendly fire'; the pilots were all rescued. During the night of 13/14 September U-408 torpedoed the 8,992-ton British tanker Atheltemplar, which later had to be abandoned. In the afternoon, in a renewed attack, the I/KG 26 lost 12 aircraft and seven crews, and the III/KG 26 eight aircraft and seven crews, but the 6,049-ton US Mary Luckenbach exploded after being hit. Aided by Swordfish anti-submarine aircraft of the Fleet Air Arm’s No. 825 Squadron operating from Avenger, the destroyer Onslow sank Korvettenkapitän Hans-Joachim Horrer’s U-589.

On 16 September bad weather prevented air activity, but on the following day German aircraft once again found the convoy, although an attack by the KG 26 was broken off. Korvettenkapitän Karl Brandenburg’s U-457 was sunk by the destroyer Impulsive. On 18 September there was another attack by the aircraft of KG 26 and KG 30 in poor visibility, but the former’s aircraft were beset by numerous torpedo failures. A Sea Hurricane from the catapult-fitted CAM-ship Empire Morn shot down two Heinkel He 115 twin-engined floatplanes.

Now escorted by the Soviet destroyers Gremyashchy, Kuybyshev, Sokrushitelny and Uritsky, and British minesweepers Britomart, Halcyon, Hazard and Salamander, the convoy lost the 5,446-ton US Kentucky. The 6,458-ton Panamanian Troubador was damaged by bombs and had to be beached in the Kola inlet, where she was broken up.

Two more merchantmen were sunk by air attack in Murmansk harbour. In all, the PQ.18 convoy lost three ships (19,742 tons) to U-boat attack and 10 (55,915 tons) to air attack.

Tirpitz did not attack the convoy, and the RAF and RAAF Hampden force undertook only one patrol, on September 14, before leaving its 23 aircraft in the USSR as the personnel returned to the UK.

The Allies saw PQ.18 as a success, for while 13 ships had been lost, 28 had arrived safely, and the Arctic convoy route, which had been suspended since the loss of PQ.17, had been re-established. Furthermore, the Allies had sunk three U-boats and shot down 40 German aircraft.

The Germans were content if not altogether happy with the losses they had inflicted, but appreciated that they had failed to stop the convoy getting through to the USSR. Their own losses, particularly of aircrew pilots, had been severe, and eroded the capability of the Luftwaffe to hinder future convoys. The German surface force had also been powerless to interfere, and its next venture, 'Regenbogen' (i) against the JW.51B convoy, would be a disaster.