U889 a TYPE IXC U-Boat
U-889 was a type IXC U-Boat which spent some months in Canadian hands after the german surrender in 1945, before being handed over to the US Navy the following year. She was examined in minute detail and the results have survived, giving a unique account of the layout and equipment of a U-Boat.
The U-889 was built by Deschimag or AG Weser Bremen in 1944 and commissioned on 8th August 1944.
She left Kiel on the 28th March 1945 and arrived at Horten two days later. On the 2nd April she sailed west with orders to attack shipping in the approaches to Halifax, but on the 10th May she was still 60 miles south of Cape Race when Admiral Donitz broadcast the order to surrender.
After surfacing she was sighted by an aircraft of no 10 Squadron RCAF and handed over to an Escort group who took her into Shelburne, Nova Scotia.
The Schnorchel, consisted of an 11.5 inch inlet trunk with a ball-float valve, surrounded by a streamlined casing. This casing extended within 4.5 ft of the inlet and formed the exhuast trunk. In the stowed position it rested horizontally below the upper casing level, to starboard at the forward end of conning tower. It was raised by a ram at its heel pivot.
The hydroplanes were both electrically and hand operated. The steering was from the control room or the conning tower, the latter position being portable so that it could be taken on the bridge when running on the surface. Hand steering was done from the after torpedo compartment with voice pipe and telephone comms.
Six torpedo tubes were fitted in the type IXC and U-889 had twelve torpedos onboard. Stowage was provided in the upper deck casing for eight air torpedos but electric torpedos could not be carried in this way.
The fitting of the schnorchel had reduced the extra torpedo stowage by two. Rails and end crossovers for a special trolley were fitted to move upper deck spares below when needed and a mast winch were provided to strike them down through the forward and aft torpedo hatches.
A pair of twin 2cm Oerlikon guns were mounted on the platform abaft the bridge. On the lower aftermost platform a twin 3.7cm Bofors was mounted with watertight ammunition lockers provided nearby. The magazine was located below the control room and ammunition was passed up the conning tower hatch to the 2cm guns and through the engine room hatch to the 3.7cm mountings.
The Hydrophone in U-889 was fitted in the extreme nose of the bow at upper deck level, with the aim of being able to listen while using the schnorchel. According to the former CO it was not particularly successful as he had been forced to stop engines every 20 minutes to allow it to be used.
The radar was housed in a recess on the port side of the bridge aft. It was raised by a hydraulic ram in the control room and training was from there as well. The Medium frequency direction finding loop was stowed on the starboard side of the bridge and was raised in a similar way. The echo sounder was fitted on the port side of the control room with the external magneto-striction hydrophones fitted in the adjacent external tank.
Submarine bubble Targets were carried in sealed cans and were ejected through a pressure gun in the heads in the after torpedo compartment. Radar decoy balloons were in the magazine. The head of the schnorchel down to the exhaust outlet was covered with a rubber coating with a 'waffle-iron' pattern on it, for absorbing radar pulses.
Enough escapes suits were carried for the entire crew. One-man rubber dinghies in back packs were also provided. In addition five large rubber dinghies were carried, on the bridge two under the 3.7cm gun platform and one forward and one aft in the deck casing. They were stowed in cylinders with a clip on lid.
Trials later performed by the Allies concluded that the U-889 was not as fast diving as RN Submarines because of the large planing area of the deck casing. She could not be taken down at any great angle, about 4 degrees being the limit, while the bow flare meant that she did not dive readily at speeds over 4 knots.
It was found that having the two periscopes in the upper conning tower instead of the control room made for problems. It was impossible to keep a periscope watch at the same time as watching the trim, and in this respect U-889 differed from the Type V11C, (HMS Graph). Running with the schnorchel put great strain on the planesmen.
The boat was very tender and susceptible to free water in the bilges. It was found that the sea tended to knock the inlet float to one side, jamming it open rather than closing it. In this way a lot of water was taken into the engine room bilges through the intake and it was necessary to keep the ballast pump running continuously. However, the schnorchel could be 'dipped' for about 40 seconds without creating much discomfort from the vacuum caused by the diesel engines.
On completion of all these trials the U-889 was handed over to the US Navy for further trials in November 1945.