A Hell of a Bomb (eBook)

2

Prelude

With such a tight schedule there could be no question of taking weekends off. Even if there had been Wallis was by now so involved with this project that he would have found that impossible to do. On Saturday 27 February, he and his staff began work on the first full-size Upkeep drawings at Burhill. This task was done in a rather unusual area of the golf clubhouse, as Norman ‘Spud’ Boorer, a draughtsman who worked under him, later explained:

At the top of the golf clubhouse was the Centre of Gravity and Weights Office, one of whose draughtsmen was Jack Froude.

In view of his own involvement in experimental work and his encouragement of Wallis after witnessing some of the Teddington trials, it seems likely that the officer concerned was Vice-Admiral Renouf.

Eric Allwright had previously worked in the Stress Office, then in the Drawing Office under Basil Stephenson, who had been Assistant Chief Designer at that time. Like the rest of the Vickers Drawing Office staff, Allwright had been moved to Burhill in 1940. By now he had a good deal of aircraft design experience, but like Wallis and the rest of the team, he had never designed a bomb until Wallis had come up with the ten-tonner and the Victory Bomber.

Although Upkeep’s outer casing would initially be spherical, its explosive would be contained within a steel cylinder. This was to be 3/8in in thickness. It would be just under 5ft long and 4ft in diameter, with detonation to be provided by hydrostatic pistols of standard Admiralty design, as used in depth charges, set to explode at thirty feet below the level of the water. Three of these were fitted, the idea being that if one was put out of action when the bomb struck the dam wall, the other two would still be left to function as the bomb sank. The self-destruct fuse, a fourth item, was intended to be armed only after the bomb had left the aircraft.

The Vickers works at Crayford would deal with Highball, while Upkeep’s steel cylinder and its wooden outer casing would be produced at other Vickers plants at Barrow, Elswick and Newcastle-upon-Tyne. Upkeeps for operational use would go to the Royal Ordnance Factory at Chorley in Lancashire for filling with Torpex, while those intended for trials would have an inert filling supplied by the ROF at Woolwich. It was intended that inert Upkeeps would be light grey in colour, while live ones, like other RAF HE bombs, would be dark green. Vickers staff would fit the wooden casings at a designated operational station.

Until he met Roy Chadwick, Wallis may not have realised that he too had been thinking along the lines of a big bomb. Sandy Jack, Chief Inspector of Avros’ Lancaster Group, later recalled how far-sighted Chadwick had been:

All this had been said well before the Lancaster, which grew out of the unsuccessful Manchester, had first seen the light of day in 1941. Like Wallis, Chadwick had always been personally involved in all aspects of aircraft design; unlike Wallis he was more polite, quietly spoken, and preferred simple solutions to detailed ones. Chadwick’s care, competence and good manners won him the respect of those he worked with, from shop-floor workers to flight test crews. It might therefore have seemed unlikely that he would have got on well with Wallis, but then Chadwick was no stranger to the abrasive characters that the aircraft industry seemed to breed in those days; Roy Dobson, the Managing Director of Avros, was a blunt Yorkshireman who tolerated neither fools nor delays.

Dobby, as he was nicknamed, possessed a fund of energy that was well known throughout his company. He was the kind of leader who was prone to visiting his factories at all hours, whose personality inspired his work force, who was accessible to just about everyone and was prepared to give them a fair hearing. If it became clear to him that modifications were necessary to improve the Lancaster’s efficiency, he would go ahead with them at once, regardless of any bureaucratic objections. Once he had authorised such changes, Dobson would back his staff – to Cabinet level, if necessary.

These two were the kind of men who had turned the disastrous Manchester into a four-engined triumph. Their attitudes, their experience and the resources they commanded were exactly what Wallis needed to make his dream become a reality and meet the deadline that had been set.

Roy Chadwick now came up with what was called the Type 464 Provisioning Lancaster. These would be Lancaster BIIIs, fitted with Packard-built Merlin 28 engines. Apart from their bomb bay modifications, Chadwick suggested the mid-upper gun turret be removed to reduce drag. This was referred to the Air Staff, who subsequently approved it. A belt drive would be fitted on the starboard side of the doorless bomb bay, connected to a motor in the fuselage, and this would spin the weapon up to the required speed before dropping. Other modifications would be found necessary as the weeks passed and the Lancasters that would take part in Operation Chastise would be very different beasts from those used by Bomber Command’s Main Force.

It was time to bring the modified Wellington back for another appearance, dropping two 3ft 10ins spheres at Chesil Beach. These had been filled with a cork and cement mixture to give ‘the anticipated density of Upkeep,’ although they were not to the same size. More useful data was obtained before Wallis and his team moved to Reculver Bay on the north Kent coast.

During March the first three inert Upkeeps reached Brooklands and were rated ‘a magnificent job’ by Wallis. However, the total number of modified Lancasters was cut back to twenty-three, which meant that only twenty would be available for operational use. The three trials aircraft would be modified at RAE Farnborough by Vickers, while the remainder would be tackled by Avro. A small four-cylinder motor produced by Vickers for submarines would be used to spin the bomb. Spinning and balancing tests at Foxwarren settled a fear Wallis had had that Upkeep would leap clear of its retaining arms if spun at 400rpm or more. This all became part of Spud Boorer’s job.