R.A.F.'s grand Slam. -- The Arnsberg viaduct after it had been attacked by 22,000-lb bombs of R.A.F. Bomber Command. In March 1945 it was announced that the R.A.F. were using against specially selected targets a 22,000 lb missile. nearly twice the size of its predecessor a 12,000 lb. missile. This massive bomb known as the "Grand Slam" is 35ft. long with a diameter of 3ft. 10ins., and is of the streamlined deep penetration type, scaled up version of the six tonner. with a tail unit. approximatel