Having seen the report about Bryan Jenkins’ RAF career, Probus member, Geoff Twine reminisces about seeing the photograph of the Avro Lancaster at the main gate to RAF Scampton.
Many years before Bryan was involved in having the Lancaster re-positioned back into its place, there had been quite a panic, when, in 1958, Lincolnshire County Council needed to change the road layout around the east side of the airfield. It was due to the RAF station needing to lengthen the runway to accommodate the soon to be arriving Avro Vulcan bombers. This meant it was necessary to move from the gate, not only the war time plane used by 617 Squadron, who were still based at RAF Scampton, but also its neighbouring war time relic. This was none other than a Grand Slam bomb, the largest non-nuclear bomb used towards the end of WW2.
Known affectionately as Ten Ton Tess it also had the semi-official name of the Earthquake bomb and also the bomb designed to miss its target. It weighed 22,000 lbs (10 tons) and was designed by Barnes Wallis the man who created the bouncing bomb used by 617 Squadron on the Dam Buster raids. With a tail fin to create spin the 25 feet bomb would be travelling at over 700 mph when it hit the earth. Having a pointed solid nose, it would penetrate deep into the ground and seconds later would detonate creating a similar effect to an earthquake which had greater damaging impact on buildings and adjacent constructions than any direct hit.
As a RAF armourer, Geoff still has his hand written records of his training on the Grand Slam bomb in the period 1949 – 1952 and clearly recalls what happened to this monster when it had to be moved for the road positioning scheme years later and what caused a major panic.
An 8 ton Coles Crane from RAF Scampton MT Section failed to lift what had been expected to be just a casing. Perhaps it had been filled by concrete which had been part of the training of ground crew responsible for loading the Grand Slam under a specially modified Avro Lancaster. Eventually it was proved to be still filled with high explosive although no records could be found as to why such a monster would have been exposed to the public for so long.
Some safety calculations were done to estimate the damage a Grand Slam detonated at ground level in the open would cause. Apart from the entire RAF station, most of the northern part of the city of Lincoln, including Lincoln Cathedral, which dates back to 1250, would have been flattened.
Using a much heavier civilian crane the Grand Slam was carefully placed on one of the RAF’s Queen Mary low loaders and taken under a police escort to Shoeburyness in Essex where it was detonated proving that the filling was very much alive.