Under attack: nowhere to run or hide
Abbekerk, August 24, 1942, 15:15
In the afternoon the lookout in the crow’s nest observed, just for a short moment, a black object on the horizon at about 55 degrees. After that, using good Prisma binoculars, from the bridge and from the foremast we observed nothing anymore. But we did change course 80 degrees to port, away from it, anyway.
Third mate Jacob Visser
We were all aware that our chance of escape in this situation was very small. If it was a U-Boat of the latest design, than his speed on the surface would be considerably higher than ours, particularly with the thick growth we had on our bottom and us sailing a zig-zag course. On top of this the U-Boat had a variety of technical aids to assist it in finding and following ships even at night. All we could do was just wait uncomplainingly.
Assistent Engineer Adriaan Kik
Ships time: all time used are referenced to Abbekerks 'ship time' unless stated differently.
Abbekerk at 16:00
After three quarters of an hours of sailing an evasive course Abbekerk resumes its original course toward ‘point H’. The sail plan now dictates a change of course to wards ‘point J’ at 16:30h. Since that is towards the point the U-boat was spotted Captain Wijker decides to stay on the present course for the time being.
U-604 at 16:00
Masts and funnel over the horizon, seen through a periscope.
To be able to attack Abbekerk and remain unseen Holtring has to maneuver his U-boat in front of Abbekerk and wait for her (under water or in the dark) to come close. To stay out of sight he has to circle around Abbekerk at great distance. The two diesel engines of U-604 give her a top speed on the surface 1,5 à 2 knots faster than Abbekerk. Overtaking is taking a long time.
Kommandant maintains contact on the control room periscope. Advantage: The greater height of eye. The bridge watch sees just the tips of the mastheads in the periscope the upper edge of the smokestack and tips of the cargo masts are seen, therefore, better estimate of target angle and exact bearings are possible.
KTB U-604, KtLt Holtring
In retrospect
The curvature of the earth limits how far a lookout can see over the horizon. (read more: https://en.wikipedia.org/wiki/Horizon)
Off course the U-boat doesn’t want to lose contact with Abbekerk, but also doesn’t want to been seen by her. This is easier than it may appear: Abbekerk is a huge freighter, more than 150 meters long and with high masts en a big funnel. From a U-boat only the conning tower is above the water and only a few meters high and wide. From a reconstruction of the pursuit based on different reports and U-604’s KTB it is clear that U-604 was approximately 90 degrees on starboard of Abbekerk when she initially saw her. It is safe to assume that Holtring started to overtake Abbekerk on starboard. To remain out of sight but just able to see Abbekerks masts and funnel she had probably to keep at least 12 to 14 miles distance.
It takes U-604 7 hours to get in place in front of Abbekerk for her first attack. With 2 knots higher speed she is able to sail about 14 miles relative to Abbekerk in that period. At 15:00 she about half way. That is about the position of 55 degrees starboard of Abbekerk the lookout reported. Unlikely as it seems at that distance, but the odds are that the lookout actually did see U-604.
After that, the submarine was never seen by the lookouts again. Also the 45 minutes evasive course is not mentioned in U-604’s KTB, but the maneuver probably helped the overtaking to go even faster.
Abbekerk at 19:00
Captain Wijker by now descides its time to set course for point J anyway. So the heading is changed from North to East-NorthEast (70 degrees). It is a major change in heading and one with far reaching consquences, we can read in U-604’s KTB.
U-604 at 19:00
[our] Boat positioned on the general course ahead of steamer. Because a moonlit night with few high clouds is anticipated, decides to attack submerged.
While boat runs submerged, the steamer changes general course to 80- degrees, probably a leg at twilight. Cannot get to a shooting position, because steamer zigs away 100 degrees.
KTB U-604, KtLt Holtring
Abbekerk at 20:00
The engine room watch I was given was from 8-12 hours and from 20- 24 hours. I can assure you that that night we went on watch with very mixed feelings. Up till now we had worked with the feeling that if it had to happen then so be it. It did not pay to try to look ahead. We had had this feeling for some time now and one got used to it. Up till now everything had gone OK so that was more or less expected to continue.
But now it was different, now we knew with almost certainty that at any moment a torpedo could crash into the engine room. We calculated our chances e.g. the length of the engine room was about one fifth of the length of the ship. There was a four fifth chance that a possible torpedo would explode in the sugar. How about that?
Assistent engineer Adriaan Kik
U-604 at 20:30
Because of the moment Captain Wijker decided to sail towards ‘point J’ anyway he – unknowingly – undermines U-604’s first attack. KtLt Holtring doesn’t understand the sudden changes of course and thinks it may be the usual thing to do at sunset. 1.5 hours after the failed attack Abbekerk is almost out of sight and Holtring comes to the surface again to circle the ship. Helped by the darkness he is able to stay much closer without being seen and the circling is performed much faster.
Abbekerk at 23:30
Abbekerk sends its location in reference to a secret point on request of the Admiralty. The location is calculated by the Captain and the first mate and send by the radio operator. Third mate Visser has the watch and captain Wijker, scheduled for the next watch, is going to have a quick lie down in the captains quarters.
Abbekerk at 23:45
The night watch went normal and at 23.45 hours I went as was usual topside to wake the people of the next watch. I left my post 7 meters under the waterline and ascended all the ladders to the deck where I had to go and check on the steering engine at the rear. At 23:45 I stepped on deck.
Assistent engineer Adriaan Kik
U-604 at 23:45 uur
High visibility. Freighter keeps zigzagging heavily. Assumed attack course, 1.5 kilometres distance.
A three torpedo spread pattern fired.
KTB U-604, KtLt Holtring
It takes the torpedoes less than 1,5 minute to reach the Abbekerk
Peter
