Several Soviet submarines had been plotted, according to STASS and shore-based intelligence reports, in the general area of his advance. He had hoped to detect at least some of these with his helicopter searches and bring them to action. How else could he carry out his mission of reducing the submarine threat to the convoys, now en route to Europe?
But the Soviet submarines were under strict orders to concentrate on the troop convoys. They had no time to lose. There were in any case other forces waiting to engage the US Strike Fleet. By 11 August, therefore, no less than eleven Soviet submarines were within 150 kilometres of the CAVALRY convoys and disposed on their line of advance. Then came the first attack, with salvoes of horizon-range supersonic cruise missiles. Sixteen missiles arrived over the convoys, fired within twenty minutes by two Charlie-class nuclear- powered submarines. Eight of the missiles were decoyed away from targets. Of the other eight, two hit one of the transports and one hit another; two more hit one of the escort carriers, which blew up and sank at once; and three more each hit one of the frigates in the same escort group. The Soviet submarines which would be first to engage the convoy formation had orders to attack the escorts and support groups. Half an hour after the submarine attacks one of the leading support group’s helicopters was quickly joined by a second and, taking it in turns, the pair between them dropped four anti-submarine torpedoes, to be rewarded very quickly by an explosion in the sea beneath them. Just as this occurred a frigate at the far side of the formation was struck by a Soviet missile and lay dead in the water. The next attack took place four hours later. Once again sixteen missiles arrived in salvoes of four, within a few minutes of each other. Once again half of them found a target. Another transport and two frigates were hit, and badly damaged. It seemed that, owing to the very high speed of advance of the convoy, the screening helicopters with their dipping sonar could not give adequate coverage far enough from the main body of the convoys. The next two attacks, again each consisting of salvoes of four missiles, came within two hours. They were again directed at the support group and succeeded in putting the light carrier temporarily out of action and sinking one frigate. This ship had the misfortune to be struck by a missile which had been successfully decoyed from another target. It was satisfactory, however, from SACLANT’s point of view, that a number of missiles had been destroyed by the Aegis anti-missile system with which the entire support group was equipped. Furthermore, both the attacking submarines were being hunted, and one of them was soon sunk.
The progress of the CAVALRY convoys across the Atlantic was of course being followed by C-in-C Soviet Northern Fleet, and by Soviet Naval Headquarters in Moscow. Although reports were incomplete, it was evident that heavy attrition of the NATO escort and support groups had been achieved. It was now time to launch the air strike, planned to coincide with the attacks of a third group of submarines, this time under orders to concentrate fire on the convoys themselves. Unfortunately for the Russians, the US Strike Fleet Atlantic was now approaching the Norwegian Sea. A Soviet surface striking force, together with its anti-submarine support group, which had sailed from the Kola Inlet on 10 August, would not be able to engage the US Strike Fleet for another twenty-four hours. By that time heavy air attacks could have been launched against the Soviet northern bases. C-in-C Northern Fleet therefore proposed to despatch an annihilating Backfire strike against the Strike Fleet. He was overruled by Moscow: ‘We do not expect Strike Fleet Atlantic to use nuclear weapons at this stage. Our primary aim is to destroy the CAVALRY convoys. Two-thirds of available Backfires are therefore to be launched against the NATO troop convoys. Our submarines in the Norwegian Sea must be concentrated against the Strike Fleet Atlantic, with diversionary air attacks only, until our surface striking force can come into action.’
The forty Backfires consequently sent by C-in-C Northern Fleet to attack the CAVALRY convoys were routed individually to a rendezvous point midway between Newfoundland and the entrance to the English Channel. The approach of the Backfires to their targets was not detected in time for a fully effective air defence disposition to be taken up by the CAVALRY convoy escorts, several of which were busily engaged in prosecuting submarine contacts. The Backfire attacks, with AS-6 air-to-surface missiles, therefore caught the NATO force at something of a disadvantage. The Aegis-fitted support group was racing to position itself with the main body of the convoys. The casualties were heavy. Seven transports were hit, four of which sank quickly. The loss of life was appalling. Of the eighty AS-6 missiles launched by the Backfires, from ranges of 220 down to 160 kilometres, no less than thirty reached a target. The escorting warships suffered as well as the transports. Only the fact that in some cases two, or even three, missiles hit the same ship limited the number of escorts sunk or damaged to five. Fifteen Backfires were destroyed.
Within two hours of the Backfire attack, the next submarine attack took place. This was less successful than the Russians had hoped. Owing to the timely arrival of a British support group, a drastic alteration of course by the convoys during the air strike, and harassment by maritime patrol aircraft, the Soviet submarines were unable to co-ordinate their attack either with each other or with the Backfires. During the next twelve-hour period three Soviet submarines were sunk, for the loss of only one more transport.
The number of Soviet submarines now in position to attack the convoys was less, in fact, than either C-in-C Northern Fleet or SACLANT had expected. There were several reasons for this. First, four Soviet submarines in transit, at high speed, had been destroyed by ASW operations in the Greenland-UK gap, unknown as yet to the Soviet commander-in-chief. Second, signals to certain Soviet submarines, ordering them to take up new patrol positions, had not been received. This involved mainly the submarines which had been sent on anti-shipping patrol prior to the declaration of the War Zone. Third, two diversionary fast convoys had been sailed twenty-four hours before the CAVALRY convoys, one along a more northerly route and another along a more southerly one. Each had attracted a group of Soviet submarines towards intercepting positions. The diversionary convoys, being free to follow highly evasive courses, which were carefully judged, had succeeded in reducing by a quarter the number of submarines which could be brought into contact with the CAVALRY convoys, once the Soviet command had realized what was going on. Finally, the use of unusually high speeds by these submarines, under orders to intercept CAVALRY at all costs, had led to several of them being detected by various means and attacked by maritime aircraft from Iceland and the Azores.
In addition to the most welcome reinforcement of the sadly depleted CAVALRY escort force by the British support group, of which the anti-submarine cruiser HMS Invincible formed part, two of JACWA’s escort groups, one with a British escort carrier, and a number of Dutch and German, as well as British frigates and destroyers, had joined the convoys by 12 August. It looked as if the worst part of the ocean transit was now over. CAVALRY would soon come under the umbrella of the United Kingdom Air Defence Region.
In the Norwegian Sea, Strike Fleet Atlantic had succeeded in destroying five of the Backfire bombers returning from their attack on CAVALRY. NATO submarines had successfully attacked the Soviet surface strike force off the North Cape and sunk a Kiev — class light aircraft carrier and a Kara-class cruiser. Early on 12 August, within twenty-four hours of the combined air and submarine attacks on the CAVALRY convoys, US Strike Fleet Atlantic began to pound the Soviet naval bases and airfields in the Kola Inlet. C-in-C Soviet Navy, Admiral Starsky, in order to justify his decision to use the main Backfire force to attack the troop convoys, rather than concentrating on neutralizing the US Strike Fleet, accepted with alacrity the reports he received of the ‘annihilation’ of the CAVALRY convoys by air and submarine attack. He therefore ordered C-in-C Northern Fleet to send his available Backfires to attack Strike Fleet Atlantic. In fact, having lost only one more transport and two escorts to submarine attack, the convoys were now, on 13 August, under air cover from the UK and France. One hazard remained to be overcome. The Le Havre mine counter-measures force, working round the clock to keep the approach channels swept, detected mines during the night of 13–14 August. Possible diversions of the troop convoys were considered. Cherbourg was in any case the destination of some of the ships. But every hour of delay in getting the troops and their equipment to the battlefield would diminish the prospect of averting the use of nuclear weapons, if the Soviet advance was to be checked. It was a balance of risks.
The French Flag Officer-in-Charge of the First Maritime District had reason to believe that the mines had been laid by a small force of Soviet coastal craft, under cover of the severe fighting in the Channel four or five days previously. It had not been possible to plot all the contacts, while so many things were happening at once. He decided, therefore, having conducted a clearance sweep and re-swept the main channel, to accept the planned number of CAVALRY transports in Le Havre, the remainder being sent to Cherbourg and Brest. In the event, there were no further casualties to the troop convoys. Out of the forty-eight transports which had sailed from the USA and Canada, twelve had been sunk or badly damaged. But ‘the US CAVALRY had arrived in time’.
