Air raids and the Rhine advance disrupt U-boat assembly

Dispersed submarine construction still depended on moving completed sections to assembly yards. In spring 1945, the Royal Air Force and US Army Air Forces targeted both individual production sites and the shipyards that would assemble the new boats. Advancing armies also interrupted the supply route. In mid-January, US forces had discovered about twenty Type XXI stern sections near Strasbourg, intended to travel down the Rhine for completion elsewhere. Their capture prevented those sections from reaching the next stage of construction. Dispersing factories could reduce exposure to a single raid while leaving the programme dependent on routes and yards that the Allies could attack or occupy.