Junkers Ju 87 single mast mounted further forward on the "greenhouse" canopy, and much simpler, lighter-weight wheel "spats" used from the -B version onwards, discarding the transverse strut bracing of the "A" version's maingear design. This new design was again tested in Spain, and after proving its abilities there, production was ramped up to 60 per month. As a result, by the outbreak of World War II, the Luftwaffe had 336 Ju 87 B-1s on hand. The B-1 was also fitted with "Jericho trumpets", essentially propeller-driven sirens with a diameter of mounted on the wing's leading edge directly forward of the landing gear,
Junkers Ju 87 needed. Skilled workers had been called up for military service in the Wehrmacht. Junkers were able to supply 300 German workers to the Weserflug factory, and as an interim solution, Soviet prisoners of war and Soviet civilians deported to Germany. Working around the clock, the shortfall was made good. WFG received an official commendation. By May 1942, demand increased further. Chief of Procurement General Walter Herthel found that each unit needed 100 Ju 87s as standard strength and an average of 20 per month to cover attrition. Not until June–December 1942 did production capacity increase, and 80 Ju 87s were