Page 63 - All About History - Issue 19-14

The Deadly Wolfpack

Captured German U-boats in Trondheim,
Norway, shortly after WWII had ended

Athree-stepguidetohuntingacrosstheworld’soceans
The hunt The attack The getaway
01 Once an Allied convoy 02 If the target was 03 If the attack was
successful the U-boat
was identified a U-boat
significant, the U-boat
approached underwater, wouldstrikeatadistance would slip away from the
seeking a gap in the of around 400-1,000m convoy, remaining on
convoy into which the boat could sail. (1,300-3,280ft) with its torpedoes. A the surface where the sonar equipment
The U-boat then took a position at right surfaced U-boat might use its 88mm could not find them. Once safe, it would
angles to the column of ships, thereby deck gun, with its more plentiful supply reload its torpedo tubes and return to
facing the largest target area. If a of shells. If torpedoes were used, a the attack. If the escorting warships
number of U-boats were to engage in a salvomightbefiredatseveraltargetsat detected it, the sub would try to outrun
wolfpack attack, then one sub would be thesametime,therebyminimisingthe the ship on the surface before diving
chose to stalk the prey while the others convoy’s response time. The furthest and disappearing back into the depths
were manoeuvred into position. target would receive the first missiles. of the ocean.

His successes came thick and fast during the early Wherever possible, Kretschmer attacked under to hunt as a wolfpack, as with the attack on convoy
years of the war and he helped pioneer the U-boats’ the cover of darkness, with lone ships sometimes SC-7. It is thought that around 250 different U-boat
most lethal killing techniques – attacking Allied targeted by the 88-millimetre deck-gun in a bid wolfpacks were formed during WWII, coming
ships from the surface while under cover of night. to save the limited supply of torpedoes. Ideally, together either for one-off engagements, or for
Once surfaced for a night attack, a Type VIIB night attacks were to be executed with the moon missions that could last several weeks. Kretschmer
U-boat like Kretschmer’s U-99, ran low in the water ahead rather than behind the U-boat, so that the proved a true pack leader, his exploits accounting
and even with its conning tower exposed was a hunter remained in the shadows while the hunted for the destruction of 56 ships – in excess of
difficult target to spot amid the ocean swell. In was silhouetted in the water, and Kretschmer 300,000 tonnes – before his capture on 17 March
addition, the Allied ships’ sonar equipment was preferred to fire just one torpedo per target, rather 1941. He fought to the very end, his capture coming
redundant once the U-boat had surfaced. The vessel than unleashing a fanned-out burst of three or four the day after his crushing assault on convoy HX-112,
also moved quicker when on the surface where it missiles. The sub would dive for just a few hours where he sunk six ships, accounting for more than
could use its diesel engines, which powered the each day, giving the crew some much-needed rest 43,000 tonnes.
boat at around 17 knots (31 kilometres per hour) — while the boat was hidden in the ocean depths. If His capture followed an unfortunate manoeuvre
when submerged and reliant on electrical power, undetected the boat would then reload, resurface executed when Kretschmer was below decks; his
the boat made little over seven knots (13 kilometres and launch another attack. watch officer ordered U-99 to dive too early, thereby
per hour). This surface speed was invariably faster Though U-boats often operated as solitary alerting HX-112’s escorts, which were assisted by
than the U-boats’ heavily laden prey. instruments of war, they were often called together radar technology. The destroyers HMS Walker and

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