First drop tests of the Alpha bombs were recorded in the same way and we were delighted to see how cleanly they dropped away and how rapidly they spread out and trailed back from the aircraft. Because the concrete Alphas suffered little damage on impact, we were able to gather them up for repeat drop trials, including releases at low level. All low-level runs were filmed from the bomb bay, by a chase Vampire and from the ground. The results were very encouraging. Impact with the ground was occurring well behind the aircraft, lateral spread was better than expected and every unit skipped back into flight.
Bev had designed and produced a small number of multidirectional fuses for first non-explosive trials. Our first live trial only involved five Alphas fitted with delay fuses amongst concrete units. No explosive was included to allow post-strike inspection of each fuse. Two of these fired instantly on impact with the ground, two functioned correctly and one failed to fire. Inspection of the latter showed that the initiating cap had fired but the delay link failed to transfer to the detonator cap. In the case of the two instantaneous bursts, initiating caps’ flame had flashed past the delay links directly to the detonator caps.
Modifications and rectification followed rapidly and we were soon testing whole clusters of Alphas charged with explosive. During this time we established that the Alpha bomblets exhibited two unexpected but highly desirable characteristics due to the rubber balls interface. The first was discovered when one bomblet had been deliberately detonated in the midst of a pyramid of unexploded bomblets (UXBs). It failed to cause a sympathetic detonation of any of the other bomblets as occurs with other explosive units—our problem was to find the widely scattered survivors for independent destruction. The second peculiarity was that we were finding hundreds of thin 20mmround shrapnel pieces that propelled like spinning saws and sliced their way into the hardest of trees. Formed by the 147 rubber balls that pressed out discs from the outer casing they spun like crazy saws aligned with their direction of flight.
By the seventh week, one week behind schedule, the engineers were totally exhausted from their intense work schedule and many sleepless nights. However, we were ready to demonstrate to the Air Staff a full-scale Alpha strike on a 1,200 x 200-metre target that had been prepared by the Range Warden, ‘Kutanga Mac’. Hundreds of cardboard and steel targets were set above ground and in trenches throughout the length and breadth of the target.
OC 5 Squadron, Randy du Rand, had not been too interested in our work at the start of Project Alpha, probably the consequence of my early tests with lead balls. However, once the project started to show positive results, nobody could have given greater support and assistance to the project team than Randy.
The Commander and his senior staff officers flew to Kutanga Range to witness the demonstration and see for themselves if the Alpha system was ready for ‘the real thing’. The project team had witnessed many trials but this was to be the first full-scale drop. We had reduced the original 400 Alphas per Canberra load down to 300 to facilitate easy loading and because we had come to realise that the reduced load covered a greater strike length than the original 800 metres we had set for ourselves. The 25% cost savings was not the reason for the reduction, but it was a huge bonus.
There was great anticipation and mounting excitement as Squadron Leader Randy du Rand opened his bomb doors late on his run-in at 400 feet at a speed of 300 knots. None of the Air Staff expected such a spectacle of dust and multiple airburst flashes as 300 bomblets did their thing. That the Alphas were bursting at perfect height well behind the Canberra was obvious to all before the sound of the explosions reached the observation point. This came as a thrilling continuous thundering of overlapping explosions.
The Commander was quite overcome by what he witnessed and showed it by shouting, “Bloody marvellous. Absolutely bloody marvellous!” Everyone present congratulated everyone else before we all set off to walk the full length of the prepared target area.
First inspection made it clear that the Alpha bomb system was just what we needed. When the visitors left, the project team commenced the detailed study that showed that the effective coverage of 300 Alphas was 1,100 metres in length by 120 metres in width. We had achieved more than we planned for! Fourteen unexploded bombs (UXBs) were defused for inspection in our ongoing attempts to reach 100% efficiency but, with 5% bomblet failures, the system already rated slightly better than the USA and UK guidelines for acceptable UXB rates in any cluster-bomb system.
The important thing was that the Alpha system was cleared for operations and the Canberra had been given the antipersonnel punch it deserved. Training of crews had been done but it was considered necessary to prepare for formation attacks, initially by three Canberras. This involved flying a very flat echelon with the aircraft spaced 100 metres apart. In this way a strike length of better than 1,000 metres and a width exceeding 300 metres could be assured. The reason for the very shallow echelon was to make certain that formating aircraft did not fall back into the curtain of shrapnel rising from the exploding bombs dropped by adjacent aircraft.
Pyrotechnics and boosted rockets
TARGET MARKING BY FIXED-WING aircraft using phosphorus rockets had been on going and all Army units carried smoke grenades and flares to mark FLOT and enemy positions. However, helicopters lacked the ability to put down markers from which to give other aircraft and ground troops direction. Rocket launchers were considered but discounted on the basis of weight and the fact that they would hinder rapid emplaning and deplaning of troops. Normal smoke grenades were unsuitable because they disintegrated when dropped from height.
I read all ASRs and, having noted pilot requests for a longduration, pyrotechnic marker device, I took this on as a project to run concurrently with the Alpha Project. Besides, there was another pyrotechnic project already in hand for a RAMS requirement.
Air Force technicians at New Sarum had recently developed a ground marker system for night bombing by Canberras. The system, known as RAMS (Radio Activated Marker Service), involved two ground flares, one of which was ignited by a radio receiver in response to a coded signal from an attacking aircraft. The other flare was manually ignited by troops on the ground. The purpose of RAMS was to give ground troops the ability to call for precision bombing of CT targets at night. This involved placing one flare as an inner marker within 300-500 metres of a live target. Having placed the inner (radio activated) marker, a bearing was taken from it to the centre of the target. The second (manually activated) flare was then sited as an outer marker on a reciprocal bearing that might be as much as 1,000 metres from the target.
To prepare for a RAMS attack, a Canberra crew needed a fairly accurate grid reference of the target itself, the magnetic bearing from outer flare to inner flare and the distance from inner flare to target. For this type of attack, bomb-aimers (Canberra navigators) used a method known as ‘off-set aiming’. It involved calculating the difference between the normal direct aiming angle at the planned bombing height and the steeper angle given by the inner flare position. The bombsight was then depressed to the calculated ‘off-set’ angle. There was nothing to prevent a reciprocal attack-line being used, in which case the sighting angle would be shallow, but it was more comfortable to over-fly the outer marker before bomb release.
When approaching target on the assigned attack heading, the pilot instructed the Army callsign to activate the outer flare for initial line-up. Thereafter the coded radio signal from the aircraft ignited the inner flare on the ground. Final adjustment to flight path was made to ensure correct alignment of the aircraft with the flares and bombs which were released the moment the bombsight crossbar reached the inner marker. 5 Squadron had practised and perfected the offset bombing system, all of which had been done at fairly high level.
Randy du Rand was happy enough with the existing RAMS system but felt it necessary to improve on the intensity of the flares for low-level night attacks. He was looking ahead, having visualised the need to use the proven offset bombing method for low-level delivery of Alpha bombs. Randy’s initiative was surprising on two counts. Firstly, the Alpha system had not yet been proven when he asked for brighter flares and, secondly, the
