The Battle of Britain Five Months That Changed History, May—October 1940 by James Holland (z-lib.org).epub

While Foylebank had been heroically doing her best to stave off the
Stukas, the terrible folly of sending the convoy into port had become
quickly apparent, not least because three freighters were hit almost as soon
as they reached the port. Not until much damage had already been done
were the orders countermanded. For Hartlepool, the orders had been an
infuriating waste of time. She had already had to turn around in an effort to
make for Portland and now had to turn back again. It was dusk by the time
she and three others were finally making headway once more, now out on
their own and quite apart from the rest of the straggling ships. But at least
the attackers had gone, and as the light began to fade they could have been
forgiven for thinking their ordeal was, for the time being, over.
At 9.30 p.m., four Schnellboote of the 1st S-Boat Flotilla left their docks at
Cherbourg and began speeding their way, one after another in line astern,
across the Channel. There was a kind of feline beauty to the Schnellboot.
Perhaps less so when docked in port, but out at sea, with her three Daimler-
Benz MB 501 engines opened to full throttle, these lithe, pale 35-metrelong
boats, scything through the water, had an appearance of awesome
power. Third in the line was S26, hurtling through the water at more than
forty knots. The prow of the boat was quite clear of the water, a huge storm
of white spray following in her wake. Either side of the prow were two
torpedo tubes, while on the forward deck was mounted an MG 34 machine
gun and at the rear a rapid-firing 20 mm cannon.
Commander of S26 was Oberleutnant zur See Kurt Fimmen, known to
all as ‘Bobby’. Good-looking, with pale blue eyes and sandy-coloured hair,
Bobby had turned twenty-nine in May. He had been born in Wittenberge, in
Brandenburg, and had joined the Kriegsmarine in 1935, as an officer cadet,
becoming a midshipman three months later. Two years later, he had joined
the S-boat arm, a branch of the German navy that had very nearly been
abandoned. A series of unreliable engines had dogged the S-boats that had
been developed, but the OKM had persisted with them and by 1939
Daimler-Benz had produced the MB 501, a robust, reliable and powerful
engine that soon proved ideal. Extravagant plans to dramatically increase
production of S-boats never came to fruition – these died with the rest of
the Z Plan – but the potential of these immensely quick inshore boats was
realized and by the time the first victories in the Low Countries were taking
place it became clear they could have an important role in harassing and