The Saumur Railway Tunnel Raid
The first 12,000lb Tallboy deep-penetration bombs developed by Barnes Wallis were used operationally on this night by No 617 Squadron in a raid on a railway tunnel near Saumur, 125 miles south of the battle area.
The raid was prepared in great haste because a German Panzer unit was expected to move by train through the tunnel.
On D-Day+3, it was an attack and the target area was illuminated with flares by 4 Lancasters of No 83 Squadron and marked at low level by 3 Mosquitos. 25 Lancasters of No 617 Squadron then dropped their Tallboys with great accuracy.
The target was marked by the Squadron Commander, Wing Commander G L Cheshire, who delivered his spotfires TI’s from an altitude of 500 feet, and the accuracy of the subsequent bombing, delivered between 8,000 and 11,000 feet, was attested by the 18 craters which could be counted within 220 yards of the tunnel mouth.
One ‘Tallboy’ had pierced the roof of the tunnel, and there were two further direct hits on the railway tracks 100 yards from the entrance. The huge bombs exploded under the ground to create miniature ‘earthquakes’; one actually pierced the roof of the tunnel and brought down a huge quantity of rock and soil. The tunnel was blocked for a considerable period and, consequently, the movement of a German panzer unit from the south into the Normandy battlefront was badly delayed. No aircraft were lost from this raid.