Hello Mr. Tore,
U-926 became KNM Kya (S307) and served until 1962, and the submarine was scrapped in 1964. Using the reshaped bridge style of the Walther U-Boats, instead of the usual VII C bridge (Minus the wintergarden, the AA platform behind the bridge and the armaments), only an insignificant increase in speed resulted, but depth keeping properties were greatly improved. The final Kya bridge/tower conversion was very modest <attached photo> compared to the original proposed Walther bridge style renovation. The bridge sail had a notch on the port side where the un-modified schnorchel raised from the unchanged bed in the wooden deck structure.
Don's Note - Because of the increased height to the aerial periscope tube casing, it looks like they extended the length of the aerial periscope to just above the schnorchel mast head for better observation while scheorchelling. This accomplished two benefits: the aerial periscope had a larger optics head and tilted for better observation, and the placement of the attack periscope inback of the diesel exhaust vent created a vision problem at times.
It looks like the Norwegians put a lot of thought into the U-Boat Type VII C renovation project, and we have Mr. Tore to thank for preserving these photos from the past.
Regards,
Don_