'Hotbed' was a British naval undertaking, with Admiral Sir Henry Moore’s Home Fleet providing distant cover, associated with the passage of the JW.64 and RA.64 convoys to and from ports in the northern USSR (3/28 February 1945).

Early in 1945 the naval base at Loch Ewe on the west coast of Scotland, which had long served as the assembly point for the Arctic convoys, was closed in order to save manpower. The JW.64 convoy, of 28 laden ships including two escorts, therefore gathered in the Clyde river to depart Greenock on 3 February.

Rear Admiral R. R. McGrigor was in overall command with the escort carriers Campania and Nairana, the light anti-aircraft cruiser Bellona, the destroyers Onslaught, Onslow, Opportune, Orwell, Serapis, Zambezi, Zealous, Zest and Canadian Sioux of the 2^nd and 17^th Destroyer Flotillas, the sloop Lapwing, the corvette Denbigh Castle, and the Free Norwegian armed whale-catcher Oksøy.

The convoy’s close escort comprised the destroyers Whitehall and Zebra (the latter having to turn back to the Færoe islands group with mechanical problems), sloops Cygnet and Lark, and the corvettes Alnwick Castle, Bamborough Castle, Bluebell and Rhododendron.

Whereas the JW.63 convoy had enjoyed a quiet passage, against the JW.64 convoy the Germans maintained almost continuous touch from the time when, on 6 February, its presence was first reported by a Junkers Ju 88 warplane, undertaking a meteorological flight, before it was shot down by two Grumman Wildcat fighters from one of the British escort carriers. However, this sighting allowed the Germans to make an early deployment of the eight U-boats of the 'Rasmus' wolfpack in the area of the Bjørnøya Passage ahead of the convoy, and on 7 February a powerful force of 48 Junkers Ju 88 torpedo bombers, of Oberstleutnant Georg Teske’s Kampfgeschwader 26, took off to attack the convoy.

Early in the morning the convoy escorts' radar equipments detected this force and McGrigor manoeuvred the convoy to place them astern, but the Germans did not in fact launch an attack, their records revealing that their shadowing aeroplane failed them at a critical moment, so causing the attack force to miss its quarry. The abortive sortie cost the Germans seven aircraft, six of them succumbing to British carrierborne fighters and the seventh to the anti-aircraft fire of Denbigh Castle.

On 8 and 9 February the U-boats and reconnaissance aircraft continued their search for the convoy, and the latter gained touch periodically. The escort carriers embarked no night-fighters, however, and therefore lacked any means to deal effectively with shadowing aircraft during the long hours of darkness. No attacks developed, however, until 10 February, when 32 torpedo bombers (14 of Major Rudolf Schmidt’s II/KG 26 and 16 of Major Wolf Harseim’s III/KG 26), launched in two waves about one hour apart, tried to break through the convoy’s fighter and gun defences. The Germans claimed major successes in these attacks, but in fact did not damage, let alone sink, a single ship. Conversely, though, the Germans suffered the loss of another seven aircraft to the fighters and the ships' anti-aircraft guns. What could not be ignored by the British, however, was the lack of fire discipline in most of the merchant vessels and, somewhat surprisingly so late into the war, some of the warships.

On 11 February the convoy’s escort was strengthened by the arrival of the Soviet destroyers Karl Libknekht, Uritskyi, Zhivuchiy and Zhosktiy, patrol ship Groza, two minesweepers and six BO-type submarine-chasers.

After its successful defence on 10 February, the JW.64 convoy had no more adventures despite the fact that 11 U-boats were on patrol across its track. None of these boats gained touch until the convoy was entering Kola inlet on the night of 12/13 February, when Oberleutnant Hans Falke’s U-992 heard the convoy’s propeller noises and fired a single torpedo on the bearing of the sounds, though it was the corvette Denbigh Castle which took the hit: the corvette was taken in tow by another of the corvettes, Bluebell, and then the Soviet salvage vessel Burevestnik, but in the entrance to the Kola inlet ran aground, capsized and had to be written off as a total loss.

The Germans now shifted all eight U-boats now available top a location close to the coast near Murmansk, and on 14 February three of the boats attacked a small convoy coming into Kola Inlet from the White Sea, sinking two large merchantmen in the same area in which Denbigh Castle had been torpedoed two days earlier.

Shortly after the JW.64 convoy’s arrival in Murmansk, news was received that the Germans were attacking the Norwegians on Sørøya, a large island at the entrance to the Altafjord. McGrigor ordered four destroyers to depart without delay, and these evacuated 525 Norwegian civilians in 'Open Door'. The destroyers then returned to Murmansk, where the Norwegians were distributed among the unladen ships of the RA.64 convoy for passage to the UK.

On the evening of 16 February, the day before the 34 ships (including one escort ) of the RA.64 convoy were due to depart, McGrigor despatched every available escort vessel (Zhivuchiy, Zhostkiy, Groza, two BO-type submarine chasers, two MO-type submarine chasers, two torpedo boats and a number of British warships) to clear the approaches to the Kola inlet, and also requested the Soviets to send up as many aircraft as possible during the following morning to help keep the U-boats submerged. The night anti-submarine sweeps achieved the destruction of Kapitänleutnant Heinz Bentzien’s U-425 by Lark and Alnwick Castle. But the Germans had assembled about six U-boats off the entrance of the Kola inlet, and the slow pace at which the RA.64 convoy, with the same escort force as the JW.64 convoy, got out to sea on 17 February provided the U-boats with an excellent opportunity. First Lark, which was sweeping ahead of the convoy, was torpedoed, probably by Oberleutnant Otto Westphalen’s U-968, had her stem blown off, but was towed back into harbour. Then the 7,176-ton US Thomas Scott was hit by the same U-boat and, after her crew had abandoned ship prematurely, sank while being towed in by a Soviet tug. Before the day was over a worse disaster took place, costing the escort force the corvette Bluebell, which was torpedoed by Korvettenkapitän Hans-Günther Lange’s U-711 and blew up with the loss of all but one of her crew.

On 18 February the Germans divided their U-boat strength so that some boats pursued the convoy and others continued to lurk off the entrance to the Kola inlet leading to the south toward Murmansk. In fact the greater danger to the convoy was a violent storm which now struck the convoy and scattered the merchant ships. The escorts had managed to shepherd all but four of them back into station when, early on 20 February, indications of an imminent air attack became strong. Although the sea was still very rough Nairana managed to fly off her Wildcat fighters, and they and the anti-aircraft guns accounted for six of KG 26's 35 aircraft which took part in the attack. The now well co-ordinated defence proved extremely effective, and none of the merchant ships was hit.

The German aircrews made wildly extravagant claims, including two cruisers, two destroyers and at least eight merchant vessels, and U-286, U-307 and U-716 were despatched to finish off the many ships which the airmen reported they had damaged. That afternoon the destroyers Savage, Scourge and Zebra, sent by Moore to replace the casualties suffered off the Kola inlet, joined the convoy. German reconnaissance aircraft were still present on 21 and 22 February, but no further attacks developed.

Then, just after most of the stragglers had rejoined the convoy, a hurricane-force storm struck and scattered the convoy once again, undoing all the good shepherding work carried out by the escorts since the previous storm. On the evening of 23 February a force of the 8./KG 26's Ju 88 torpedo-bombers, which had been searching for the convoy, sank a straggler, the 7,177-ton US Henry Bacon; this was the last Allied ship to be sunk by German aircraft in World War II. The ship’s boats were found by destroyers, which rescued 65 survivors of a crew of 41 seamen and 26 gunners. For the next two days the gales continued to blow with unabated fury, the convoy made little progress, and the escorts were running so short of fuel that they had to be sent to the Færoe islands group to replenish as fuelling at sea was impossible. Moore therefore sent out three more destroyers, Cavalier, Myngs and Scorpion, which joined the convoy on the evening of 25 February. As the battered struggled slowly past the Færoe islands group the weather at last started to abate, and most of the ships reached the Clyde river safely on 1 March. One straggler, which had been missing since the first gale struck the convoy, finally made harbour safely after nothing had been heard of her for a week.

Counting the two Arkhangyel’sk ships sunk before the convoy sailed from the Kola inlet, the RA.64 convoy had lost four merchantmen. But no Arctic convoy ever suffered a more severe buffeting from the weather, and 12 of the 16 destroyers which took part in the operation had to be docked for hull repairs.