Hi

When the german u-boat command realised that their type VII and IX boats had too poor performance too meet the new weapons and tactics used by the allies, did they ever consider to do a GUPPY type conversion to their existing U-boats ?
I´ve never heard about such a project, but wouldn´t it be a símpler and more economic way to cope with the new requirements ?
Proffessor walter had already shown his genius, coldn´t german engineers consult him in a radical modernisation program ?
One thing that i thought might have stopped such a project was the size of the german boats ; The british A and T classes and the U.S. Balao and Tench were much larger than their german counterparts, and maybe the small size of the type VII especially didn´t allow any more cells to be installed ? We all know how crammed the german boats were...
Such a converted boat would of course not equal the type XXI, but if a great number could have been made operational in a short time, it might have been able to do what the XXI arrived to late to do ; Win the battle of the Atlantic.
/ Nils