Erich Topp joined the German U-Boat arm in October 1937 (Crew 34), and
a year later was appointed as a watch officer on U-46 (Kptlt. Herbert
Sohler). After four patrols, Topp was given command of U-57, a Type II
boat, with which he sank six ships totaling 37,000 tons.
After 17 combat war patrols, Topp was reassigned as commander of the
27th U-Boat Flotilla. In that capacity he trained new crews and in 1944
drafted the tactical battle instructions for the Type XXI Electro
boats.
After the war, Topp worked as a common fisherman and eventually
became a successful architect. He joined the West German Navy in 1958
and served in several high-ranking staff positions with NATO.
Topp retired as a Konteradmiral in December 1969. Thereafter, he served
as an industrial consultant for many years and penned his autobiography, The Odyssey of a U-Boat Commander: The Recollections of Erich Topp (Praeger, 1992). Admiral Topp lives today in Remagen, Germany and is a consultant on SSI's coming Silent Hunter II and Destroyer Command.
The Wolf Pack
Admiral Donitz developed this system as a means of stopping the shipment of
supplies across the Atlantic Ocean. In the beginning of the war, our secret
service was able to decode the enemy messages given to the convoys. This
enabled us to locate our submarines in a line confronting the expected
course of the convoy.
A distance of about 50 km was to be kept between each
boat, although in practice this was not always possible. This enabled our
boats to either find the convoy visually or with our listening devices,
which would pick up their propeller noises. The idea was that the first
boat to establish contact with the convoy would radio headquarters and
other boats in the line (or group) and alert them to the presence of the
convoy.
All the boats were then to proceed as fast as possible (maximum
surface speed was about 18 knots) to establish visual contact with the
convoy and await instructions. The average speed of a typical Atlantic
convoy was about 8-9 knots, a speed dependent on the slowest ship in the
convoy.
If our submarines established visual contact during daylight hours, we were
instructed to obtain a position ahead of the convoy, dive, and conduct an
attack at periscope depth. Convoys were usually protected by destroyers and
corvettes escorts, which were typically posted 2,000 - 3,000 meters outside
the convoy, forming a protective ring around the ships. Our goal was to
penetrate this protective line and to attack the ships from as close as
possible, and then withdraw to reload our torpedoes, and then attack once
again.
Allied advances in the field of electronics changed Wolf Pack tactics
considerably. The introduction of the ship-borne
High-Frequency-Direction-Finder, known as "Huff-Duff," fitted in increasing
numbers of ships from the end of 1942 onward, enabled convoy escorts to
take accurate bearings up to 25 km on U-boats, which transmitted near
convoys.
The effectiveness of this was much enhanced by the German practice
of abandoning radio silence, once contact was established with a convoy.
This resulted in the loss of many boats and crews, who did not realize they
were announcing their location to the enemy.
Another major development was
radar. In darkness or in fog, the ship-borne radar on board of the Allied
escorts (and airplanes) robbed the U-boats of their prime advantage:
invisibility. These two factors, with advances in defensive and offensive
escort tactics, better depth-charges, and the reading of transmissions
because of the breaking of Enigma, made the Wolf Pack tactic obsolete.
Although we suspected certain advancements, we had no knowledge of the
electronic advances on the Allied side. We did not know anything of the
Huff-Duff system or Enigma until after the end of the war. Once U-boats
lost their invisibility, their technical and tactical limitations became
obvious. The Wolf Pack tactic had lost its effectiveness.
While on the surface, even when facing single escorts, a U-boat's self defense
capabilities were very low. When forced to submerge, the chances of
escaping a persistent hunt by an experienced team of warships--and the
convoy escorts became more experienced as the war progressed -- were
limited by the low underwater speed and endurance.
MY EXPERIENCES
During the pre-war years and the first two years of the
war, U-boats conducted two-week tactical training excercises in the Baltic
Sea. These exhausting exercises consisted of simulated attacks on convoys,
formed of eight or more ships protected by escorts and airplanes. I engaged
in these both as a commander of a U-boat, and later in the war as a
Flotilla commander.
When attacking convoys early in the war, I always tried to pass the escorts
and, if possible, attack from between the lines of the merchant ships. I
had to keep in mind that I could not launch an attack from a distance less
than 300 meters. Otherwise, we risked blowing ourselves up with our own
torpedos.
Between the lines of the convoy I had some freedom to maneuver,
because the merchant ships were bound to a certain order that did not allow
them--even if they saw my U-boat--to change their course considerably, even
to ram me.
The advances in Allied technology were evident when I attacked a convoy in
1942 on its way from Gibraltar to England. This convoy was under the
command of the famous convoy-leader John Walker. The Wolf Pack system
failed.
Of the several U-boats that tried to attack this convoy, only my
boat was able to attack during the night at a distance of 3,000 meters. The
other boats were prevented from approaching close enough or were sunk.
Huff-Duff, radar, and advanced tactics defeated our best efforts.
