(sorry guys this report is going to be a long one... don't bother reading if you're in a hurry! And good to see some action packed reports here in the thread
)
Leutnant z.s. Helmut Unger
U-552, VIIC
11. Flotille, Bergen
4.9.1942
18:09. Länge 10, 23' Ost, Breite 72, 14' Nord. Cloudy, heavy rain, visibility 700 – 1100 meters. First attempt to attack the convoy we were chasing had to be aborted due to bad weather. The convoy's course was difficult to estimate from hydrophone bearings while moving and then diving again to get new bearings. Compressed air was down to 75 %. The second attempt in locating the convoy was made more patiently and a course estimate of 250 – 270 degrees was made. While approaching the convoy Metox gave four warnings. Our own radar didn't locate anything approaching.
From about 5 – 10 kilometers from the convoy the approach was made submerged while trying to make a better estimate of the convoy's course. Judging by the hydrophone screws the front and sides of the convoy were covered by 5 – 6 escorts. A River class frigate was sighted 1100 meters from us, making approximately 10 knots. The AOB and course was too difficult to estimate in low visibility and our shooting solution was very much an estimation and I decided not to shoot. An 11000 BRT tanker was sighted but we couldn't get a decent solution since the ship was too close to our boat.
However at 16:57 hours an aft torpedo was shot at a 9000 BRT frachter. Impact pistol, depth 4 meters, range 700 meters, AOB 90 degrees Steuerbord, Schusswinkel 21, bearing 180. The ship's speed was estimated to be 7 knots. Right after the first shot another torpedo from rohr 1 was shot at a 3800 BRT frachter. Impact pistol, depth 4 meters, range 470 meters, AOB 84 backbord, schusswinkel 28, bearing 6 degrees.
The estimations were made hurriedly, and judging by the hydrophone sounds the torpedo shot at the smaller ship was very short. The aft torpedo however hit it's target and a huge series of explosions was heard on the hydrophone, followed by sounds of a sinking ship. The 9000 BRT frachter was probably carrying ammunition for the convoy and the torpedo must have exploded those too.
Escaped making 1 – 2 knots, diving to A+70, first just going straight ahead, and when the escorts were estimated at having no clue of our position, turning away from the convoy's direction. Now reloading, 10 G7e torpedoes left inside the boat and 2 G7a's outside.
In this kind of weather the new FAT torpedoes that have been experimented successfully by U-159 might be very useful. Not having a revolving radar makes it more difficult to approach the convoy in this weather– we have to keep our bow pointed to the convoy's general direction if we are to get a warning about an escort making a dash for us.
5.9.1942
05:31. Länge 9, 03' Ost, Breite 72, 14' Nord. Cloudy, heavy rain, visibility 700 – 1100 meters. A second attack against the convoy was made. After five hours of regular hydrophone checks and maneuvering, the convoy's course was estimated at 261 degrees, 7 knots. The attack was made with a course of 171 degrees from inside the convoy, which was easy as there were only escorts on the sides of the convoy. Fast screws were heard at a relative bearing of 230, probably the front guard had left it's post and was returning some distance away. One of the port escorts was seen, but not recognized in low visibility. A 1800 BRT Küstenmotorschiff was seen but was too close for attacking at a good AOB. At 05:04 hours three G7e torpedoes were shot at an 11000 BRT walfabriksschiff. Range 870 meters, speed 7 knots, bearing 343, AOB 76, schusswinkel 0. Three hits were heard on the hydrophone in less than a minute and afterwards sounds of metal bending. Presumed sunk. Escaped diving at silent speed to A+80, no initial course change. We are now getting ready to start pulling away from the convoy. The escorts didn't notice us.
Oberfähnrich z.s. Akermann deserves a medal for his efforts on the accurate estimation of the convoy's course in these weather conditions, as do radiomen Stwora and Gertenbach for accurate enough hydrophone bearings and keeping us away from merchants on collision course. In fact all of the crew have made an immense job in our patrol so far, but I probably can't get Iron crosses for everyone – though I might be able to pull that off, if we manage to sink a couple of big ones more. With seven ETO's left inside the boat (two ATO's outside, but not much use in this weather) I expect we should be able to attack the convoy with full force twice more.
10:33. Länge 8, 34' Ost, Breite 72, 03' Nord. Cloudy, heavy rain, visibility 700 – 1100 meters. At 9:34 hours a destroyer was sighted at a relative bearing of 180 degrees, distance 900 - 1000 meters. The escort opened fire immediately and put it's searchlight on. Crash dive, AK, hard turn starboard, 2 BOLD canisters launched while diving to A+70. The boat was rattled by presumably 20 mm or 37 mm gunfire.
The destroyer dropped 6 sets of depth charges, presumably on the sites where the decoys where launched. The intervals between drops were between 5 – 6 minutes. Between 5 – 7 depth charges were dropped in each set. The first DC's dropped in a set exploded after a descend of 15-16 seconds and the second DC's dropped after 20-25 seconds. Presumably the sets are designed so that the first DC's explode nearer the surface than the latter ones. If this is the case, the DC's probably affect a very narrow, but deep area.
No internal damage to the boat from getting hit by the gunfire has been found. DC's probably were too far away to affect the boat. Damage to the hull can't be inspected until we surface and the wind gets mild enough for the crew to be able to walk on the hull. I have decided to let the convoy pass. We are now headed towards the back of the convoy, in hope of spotting possible undefended stragglers. If the weather doesn't change, we have to sail to nearest port in Bodö to inscpect the boat.
Prior to getting attacked by the destroyer at 9:34, Metox had given radar warning signals at 6:32, 7:15, 7:25, 7:45 and 7:56 hours. I took these as coming from the general direction of the convoy and presumed them harmless and I didn't order a zig zag course. However, it is possible that an escort slipped behind us from the bearings calculated and approached from 180 degrees relative bearing in order to get close from direction where GHG has the worst chance of picking the hunter. I badly underestimated the enemy's capabilities and we only escaped because the destroyer's gunners didn't do their job properly. In low visibility it might be better to follow a convoy out of the range of their radar and while making hydrophone checks, also check one's 180 degree position.
The younger crewmen seem to be quite happy about our close escape and perhaps not realizing how close to death we really were. The more experienced men seem to be more aware of the seriousness of the event, but keep a brave face in order to not frighten the youngsters.
14:48. Länge 8, 36' Ost, Breite 71, 57' Nord. Cloudy, medium rain, visibility 700 – 1100 meters. At 12:13 hours there was a contact on the hydrophone. Estimated targets range, speed and course from FuMo 29 bearings as 261 degrees, 2 knots. At 14:05 hours one G7e shot from Rohr 5 at a 1600 BRT trampfrachter. Range estimated at 600 meters, AOB 90, schusswinkel 0, impact pistol, depth 3 meters, bearing 178 degrees. 45 seconds later a hit between the front masts, the aiming point was just before the bridge. 42 minutes later sounds of a sinking ship on the hydrophone. Six G7e torpedoes left inside the boat and two G7a's in outside storage. I am continuing towards the port at Bodö.
Unger