It superseded Operation Fritham, an expedition in May, to secure the coal mines on Spitsbergen, the main island of the Svalbard Archipelago which had failed when attacked by four German Focke-Wulf Fw 200 Condor reconnaissance bombers.

The Admiralty arranged a survey flight by a Catalina flying boat from RAF Coastal Command but already knew much of what had happened, through Ultra decrypts of Luftwaffe Enigma coded wireless signals.

The German airstrip was blocked and on 23 July, a Ju 88, carrying an experienced crew and two senior officials, was shot down while flying low over the landing ground.

Drift mines were linked to the shore by overhead cable tracks or rails and coal dumped over the winter was collected by ship after the summer thaw.

[1] The British Government Code and Cypher School (GC&CS) based at Bletchley Park housed a small industry of code-breakers and traffic analysts.

Combined with their knowledge of Luftwaffe procedures, the computers could give fairly accurate details of German reconnaissance sorties and sometimes predicted attacks twenty minutes before they were detected by radar.

[4] From 25 July to 9 August 1940, the cruiser Admiral Hipper sailed from Trondheim to search the area from Tromsø to Bear Island and Svalbard to intercept British ships returning from Petsamo but found only a Finnish freighter.

Norwegian and Russian civilians were to be evacuated using the same two cruisers, with five destroyer escorts, an oiler and RMS Empress of Canada, a troop transport carrying 645 men, mainly Canadian infantry.

[8] Normal business was kept up at the Barentsburg wireless station by the Norwegian Military Governor Designate, Lieutenant Ragnvald Tamber; three colliers sent from the mainland were hijacked along with the seal ship MS Selis, the ice-breaker SS Isbjørn, a tug and two fishing boats.

The Heinkel He 111s and Junkers Ju 88s of Wekusta 5 ranged over the Arctic Ocean, past Spitsbergen and Jan Mayen towards Greenland; the experience gained made the unit capable of the transporting and supplying manned and automatic weather stations.

[13] After the wireless on Spitsbergen had mysteriously ceased transmission in early September, German reconnaissance flights from Banak discovered the Canadian demolitions, burning coal dumps and saw one man, a conscientious objector who had refused to leave, waving to them.

Advent Bay (Adventfjorden) was chosen for its broad valley, making a safer approach for aircraft; its subsoil of alluvial gravel was acceptable for a landing ground.

Major Amherst Whatman, a Polar explorer and signals specialist, repaired and operated the wireless set but it broke down on the journey to Iceland and was not reliable for the rest of the voyage.

The local swine herd had been slaughtered during Gauntlet and the arctic cold had preserved the meat; wild duck could be plundered for eggs and an infirmary was also found, still stocked with dressings for the wounded.

Lieutenant Ove Roll Lund sent parties south to Sveagruva in Van Mijenfjorden (Lowe Sound) and to reconnoitre the Germans in Advent Bay around the airstrip at Bansö.

[23] After Convoy PQ 16 (21–30 May 1942) Air-Chief Marshal Philip Joubert, the AOC Coastal Command, mindful of the lack of aircraft carriers and the limited help available from the Soviet Air Forces (Voyenno-Vozdushnye Sily, VVS), suggested that a flying-boat base be established on Spitsbergen.

[24] At the end of June, Glen delivered his report to the Admiralty, describing the calamity of 14 May, the strength of the German party at Bansö and the prospects of achieving the objectives of Fritham by sending reinforcements.

To avoid another disaster, the occupation of Spitsbergen was to remain under the command of Norwegian government forces but the Navy would be responsible for delivering supplies and the trips were to be synchronised with outbound PQ convoys.

[25] The Admiralty sent Glen and the pilot, Flight Lieutenant D. E. (Tim) Healy, to brief Vice-Admiral S. S. Bomham-Carter, commander of the 18th Cruiser Squadron at Greenock in Scotland and were asked to photograph the Spitsbergen coast from about 100 ft (30 m) to simulate the view from Manchester's bridge.

The crew took pictures of the coast to Cape Linné, Green Harbour and Barentsburg, made contact with Fritham Force and then photographed the pier, the navigator hanging out of the port blister with a camera, held fast by a colleague.

The Catalina crew dropped a message to the ground party as they flew back and set a middling course for Shetland and Iceland, ignoring the itinerary for Jan Mayen.

In the midnight sun (20 April – 22 August) as mid-summer approached, the ice in the west of the fiord near the Allied positions cleared faster than that by the Germans in the east end.

Ship's boats, motorboats, a motor dinghy, a pinnace, cutters and whalers made 121 round trips in six hours, unloading the Norwegians and the supplies, including short-wave wireless, 40 mm Bofors anti-aircraft guns, skis, sledges and other Arctic warfare equipment.

[32] On 12 July a supply trip from 210 Squadron was to deliver the missing Colt ammunition belts to Barentsburg, before conducting a reconnaissance of the Barents Sea to search for survivors of Convoy PQ 17, which has lost 24 ships.

[33][e] Once the Colt parts had been delivered, Ullring had one mounted in a cutter and on 15 July, set off in the midnight sun with ten men, to attack the Germans at Longyearbyen in Advent Bay.

The Krote near the shore at Hjorthamn was found, dismantled and returned to Barentsburg for shipment to Britain and a party with two Colt and two Browning machine guns was left behind to guard the airstrip.

[34] On 21 July, a Ju 88 flying over Green Harbour was fired on by the Oerlikon gunners; the port engine trailed smoke and a hole appeared in one of the wing tips.

[37] The remainder of Fritham Force at Barentsburg was consolidated by the reinforcements of Operation Gearbox and its sequels, a weather station was set up and wireless contact with the Admiralty regained.

[38] The survivors of Operation Fritham provided excellent local knowledge and with the arrival of the Gearbox personnel, could do more than subsist and dodge attacks by German aircraft.

The flight of Catalina N-Nuts to Spitsbergen on 13 July with the Colt parts and other supplies, thence to north Russia to search for PQ 17 survivors, informed the British naval authorities in Murmansk that the Barents Sea was free of ice.