"Royal Air Force- Operations by the Photographic Reconnaissance Units, 1939-1945." Oblique photographic-reconnaissance aerial of the twin railway viaducts at Schildesche, Bielefeld, following the successful daylight attack by 15 Avro Lancasters of No. 617 Squadron RAF on 14 March 1945. Five arches of the viaducts collapsed after 22,000-lb 'Grand Slam' and 12,000-lb 'Tallboy' deep penetration bombs were dropped in the target area. Numerous craters from previous attempts to demolish the structure can be seen covering the floor of the Johannisbach Valley.