The U-106 in this story was a U-93-class U-boat.
From
Wiki *:
Displacement: 838 tons (surfaced)
1000 tons (submerged)
1270tons (total)
Length: 71.55 m (overall)
56.05 m (pressure hull)
Beam: 6.20 m (overall)
4.18 m (pressure hull)
Draught: 3.94 m
Propulsion: 2400 hp (surfaced)
1200 hp (submerged)
Speed: 16.8 knots (surfaced)
9.1 knots (submerged)
Range: 11,280 miles @ 8 kn(surfaced) 56 @ 5 kn miles (submerged)
Test depth: ~50 m (164 feet)
Complement: 39 men
Armament: 16 torpedoes (4/2 in bow/stern tubes)
105mm deck gun with 140 ounds, and/or 1 8.8cm/30 gun, or 1 105mm gun (220 rounds)
* - Note that the title of the Wiki page refers to a Type 97 U-Boat. No such thing. There was a U-97, but it was a Type U-93 boat. I think that the author of these related pages just got sloppy copying the template from the Type U-87 to the Type U-93 page.