The
Home Station during the Final Phase of the War
IN MAY 1945,
WITH THE END OF THE WAR IN EUROPE, FO(SM) no longer had responsibility
for any operations in Home waters. Instead he had the problem
of the technical supervision of the surrender of the German
U-boats. The war was still in progress in the Far East and his
most important task was still the building, manning, trials
and training of the stream of new and refitted submarines proceeding
to that area. At the same time, he had to be mindful of the
problems of demobilisation, the size and shape of the post war
submarine fleet and its return to peacetime conditions.
On 4th May,
the German high command ordered all U-Boats to cease hostilities
and return to base. There were fifty-seven U-boats at sea, but
only eight complied at once, the others either did not receive
the message or disregarded it. Four days later, after the German
surrender, the Admiralty ordered all U-boats to surface, fly
a black flag and proceed to Loch Eriboll in Scotland, Beaumaris
in Anglesey, or to Weymouth. The first U-boat surrendered at
Loch Eriboll on 10th and was inspected and then sent on, with
a British guard onboard, and under escort, to Loch Alsh and
finally, with other surrendered U- boats, to either Loch Ryan
in Scotland or Lisahally in Northern Ireland. The whole operation
was under the command of the C-in-C Western Approaches, but
FO(SM) provided the inspection teams and supervision of the
U-boats after arrival. Escort groups were despatched to Norway
to send all U-boats there that could be made fit for sea to
Lisahally or Loch Ryan. By the end of July there were seventy-five
U-boats at Loch Ryan and fifty-one at Lisahally. Many U-boats
were also surrendered in German ports. Altogether one hundred
and fifty-six were turned over, but another two hundred and
twenty-one were scuttled by their crews.
The interest
of FO(SM) in the German U-boats was not confined to their care
and maintenance. He had an intense interest in the German U-boat
developments made during the last two years of the Battle of
the Atlantic. This interest was stimulated not only by a desire
to use these developments to improve the performance of our
own submarines, but above all to produce countermeasures to
them. The Admiralty already had full information about the German
Type VII U-boat as we had captured U570 in 1941 and had
run full trials with her.
The first
of the new developments was the 'schnorkel', which enabled a
submarine to use its diesel engines when submerged at periscope
depth. It could thereby re-charge its batteries without surfacing
and could make passages at six knots or so without showing more
than the top of the schnorkel tube above the surface. The majority
of German U-boats were now fitted with this device, which had
revolutionised the Battle of the Atlantic by making radar, both
from ships and aircraft, of little value as an anti-submarine
measure. As has been told in Chapter XXVIII, we had already
decided to develop the schnorkel, or snort as the British version
was called, and it was being fitted in Truant.
The first U-boat fitted with schnorkel that fell into our hands
was U249, which surrendered off the Lizard in May. A
number of other interesting devices also fell into our hands,
including the 'gnat' homing torpedo, various search receivers
for intercepting radar, asdic decoys, and radio short transmission
devices which made direction finding difficult. Of particular
interest to the antisubmarine world was U1105, which
was covered with a rubber anti-asdic coating, code named 'Alberich'.
She was taken over by a British crew for trials together with
U1171 without the coating, for comparison. Two other
U-boats, U776 and U1023, were also manned by British
crews as part of the Victory Celebrations during the summer,
and made visits to British ports on the east and west coasts
respectively before being laid up in Loch Ryan.
Of extreme
interest were the new German U-boats of Types XXI and XXIII
with their high underwater speed and endurance. A few of these
new types were operational by the time of the surrender. U2511
(Type XXI) was actually at sea north of the Faroes, and U2326
(Type XXIII) sank two ships off the Firth of Forth on the last
day of the war. Twelve more Type XXI were ready for sea and
another forty-four had been completed with yet another fifty
in an advanced stage of construction. Seventeen of the Type
XXIII were ready for sea. Many of these were scuttled or sabotaged
by their crews in Germany but U3035 (Type XXI) fell into
our hands in Norway, and U2326 (Type XXIII) surrendered
at a British port. British crews at once manned both of these
and U3035 was brought back to the United Kingdom. Full
'first of class' trials were carried out in U2502 (Type
XXI) and U2326 (Type XXIII) during the summer. The Type
XXI were found to have a submerged speed of sixteen knots for
an hour, six knots for forty-eight hours and three knots for
the best part of a week. They had a new periscopic schnorkel
with which they could make eleven knots, and they had an endurance
of 11,150 miles and carried twenty-three torpedoes. The Type
XXIII had a submerged speed of twelve and a half knots but had
a shortened endurance of only 50 miles when schnorkelling and
carried only two torpedo tubes. It was clear that the worst
fears of the antisubmarine world were confirmed. The Type XXI
had the capability of operating against an opposition fitted
with air and surface radar and their submerged speed would enable
them to avoid attack by any existing underwater weapons including
depth charges, 'Squid' and 'Hedgehog'. It is of interest that,
at this time, a Joint Chiefs' of Staff planning paper suggested
that we should scrap our existing fleet of A and T-class submarines
and take over an equal number of Type XXI boats from the Germans.
There was a more advanced German submarine development than
the Type XXI, of which our intelligence had given us warning.
This was a totally new system of propulsion for submarines expected
to give high speed completely submerged for considerable periods.
The new system was the invention of a German scientist, Dr H
Walter. It was to replace electric batteries and motors for
submerged propulsion with turbines driven by a system using
hydrogen peroxide. This system was independent of the atmosphere
and the exhaust would be steam and pure carbon dioxide, which,
being soluble in water, would leave no track. This system was
capable of propelling a submarine at over twenty knots for five
hours or so. German developments were in an advanced stage.
They had built and tried a small experimental submarine and
had then constructed a class of four small coastal boats, which
were still experimental. These were to be followed by three
larger, but still coastal boats, that were expected to become
operational. At the surrender, all these submarines were scuttled
and the Germans hoped to conceal the whole development project
from the Allies. Advanced intelligence units with the army failed
to prevent the scuttlings but soon picked up the threads including
Dr Walter, and found where the most important hydrogen peroxide
submarines had been sunk. U1407 at Cuxhaven was salved
without delay and was towed across to Vickers Armstrongs at
Barrow for examination and possible refit followed by trials2.
THE WAR IN
THE FAR EAST was not expected to end until Japan had been
invaded and this would not be until well into 1946. The strength
of forty operational boats there, approved by the Admiralty
in 1944, had now been reduced to thirty by the statement of
the Commander(Submarines) Seventh Fleet, that he could not
operate more than twenty British submarines in the Pacific
and the fact that ten was the most that could be usefully
employed in the East Indies. Nevertheless this total still
required all new submarines of the S and T-classes and some
of those refitted, to keep up strength to even thirty boats.
Amphion,
first of the A-class, was doing her trials and others of the
class were nearing completion. The Third Submarine Flotilla,
based in the Holy Loch in the Clyde, was still working hard
to train and deliver these boats to the Far East and this
flotilla also looked after the trials of the British manned
ex-German U-boats. By midsummer, the last three boats of the
V-class3 had been
delivered and the T and S-class building programmes were continuing,
although no new boats of these classes had been ordered since
1943. There were still ten S-class under construction and
twelve of the T-class. The main building programme now consisted
of twenty-five boats of the A-class in various stages of construction
with another nineteen projected.
The other
four submarine flotillas in the United Kingdom were still
in existence. The Seventh Flotilla at Rothesay continued its
duty of providing all the anti-submarine training submarines.
Still based on the old depot ship Cyclops,
it consisted of eighteen submarines, all except H34
and H50
being modern boats of wartime construction mostly of the U
and V-classes. It also had Seraph
and Sceptre,
the first of the de-militarised 'fast antisubmarine targets'
and Vulpine,
fitted with a dummy snort. The Fifth Submarine Flotilla at
Fort Blockhouse in Gosport had been in commission as a submarine
base throughout the war and had performed a number of functions
including that of the submarine depot for personnel, certain
training duties and the supervision of submarine refits in
the Royal Dockyards in the south of the country. It had been
commanded by Rear Admiral RB Darke, a retired first world
war submariner, who had literally 'held the fort' for over
four years. He was now allowed to retire a second time and
was relieved by Captain GC Phillips DSO GM RN. The Fifth Flotilla
now had four submarines of its own and was beginning to resume
its prewar functions again. The Sixth Flotilla, shore-based
at Blyth, was still in existence as a submarine training establishment
and had four boats, three of which were modern, to carry out
this task. The Ninth Submarine Flotilla, with its shore base
at Dundee, was still running for the benefit of our Allies.
Three Netherlands, one Polish and one Norwegian submarine
were attached, refitting or preparing to return to National
control. Finally the Twelfth Submarine Flotilla, shore based
at Kames Bay in Bute, had just closed down. It had been the
training establishment for X-craft and chariots. Of the remaining
X-craft, XE1-6 were scrapped in Australia and XE7
and XE9 were already in reserve at Fort Blockhouse.
XE8 and XE12 were now also paid off and sent
south by rail to Fort Blockhouse4.
Captain PQ Roberts was transferred to Lisahally to command
the surrendered German U-boats.
Well before
the end of the war, the British submarine branch had more
submarines than it could man. It was therefore decided to
scrap all the older pre-war submarines and a number of these
were disposed of, some as bottom targets for asdic exercises,
during the summer of 1945.
THE ATOM BOMB
AND THE SURRENDER of Japan in August came as great a surprise
to those at home as in the Far East. Demobilisation now took
priority over all else and the ordering home of the Second
and Eighth Flotillas from the Far East introduced problems
which completely changed any plans that had been made for
the future. All this was complicated by the move of FO(SM)
from his London headquarters at Northways, Swiss Cottage,
back to Fort Blockhouse, which had already been arranged and
which took place on 23rd September. The Fifth Flotilla at
Fort Blockhouse now had six submarines in running order and
another ten refitting in the dockyards. It also included P614,
preparing to transfer to Turkey. It had thirteen submarines
in reserve as well, two of which were laid up at Blyth and
nine were to be laid up at Falmouth with one at Sheerness
and another at Plymouth. Some of these were waiting to be
scrapped and others had been damaged in action and were awaiting
a decision about their future. The Sixth Flotilla at Blyth
had been wound up and its submarines and their training function
had been transferred to Fort Blockhouse or the Seventh Flotilla
at Rothesay, which with seventeen boats continued as before.
The Third Flotilla in the Holy Loch continued with working
up submarines as they were completed or finished their refits.
In September these boats included the first two of the A-class,
four T-class and three S-class. The flotilla also supervised
the refits of two submarines in shipyards in the north. Finally
the flotilla included five British manned U-boats, which were
still doing trials. The shore submarine base at Dundee was
still operating for the convenience of our Allies, and there
were two Polish, six Netherlands and one Norwegian submarine
completing trials, refitting or awaiting return to their countries.
It had already
been decided in principle by the Allies that the German U-boat
fleet should be scuttled in the Atlantic. In August and September
a Tripartite Commission from the British, American and Russian
Navies visited Loch Ryan and Lisahally to decide which U-boats
should be allocated to the three powers. The Royal Navy's share
was fourteen boats including all those that had been manned
for trials and also U1407, the hydrogen peroxide propelled
submarine, now at Vickers. The other two powers were allocated
similar portions of the U-boat fleet. It was confirmed that
the rest should be scuttled in the Atlantic as soon as possible.
It had been hoped to complete the operation before the winter,
but in fact it was not finished until January 1946. The French
and Norwegian Navies now claimed a share of the U-boats and
the Royal Navy handed on six boats of their allocation to them5.The
trials of the U-boats, which had been commissioned with British
crews, were completed by the end of the year, and they were
placed in reserve to be used for explosive and other tests by
the Ship Target Trials Committee of the Admiralty.
Although a
considerable number of British submarines had, by September
1945, been scrapped, including nearly all those of pre-war construction,
there were still 105 boats in the fleet. Furthermore there were
another 65 submarines building or on order. No formal appreciation
seems to have been made, at this time, of the size of the post
war submarine fleet or its composition. Indeed, with the advent
of nuclear weapons, the whole future of naval warfare was obscure
and in doubt. Furthermore with the defeat of Germany, Italy
and Japan and with Russia an ally, it was difficult to discern
a threat against which conventional defence forces would be
needed in the future. Nevertheless it was obvious that the building
programme must be drastically cut and that to comply with the
imperative of demobilisation, the overall size of the submarine
fleet would have to be reduced by scrapping or putting submarines
into reserve.
Many of the
submarines building were nearing completion. All their machinery
and equipment had already been procured and it would obviously
be wasteful not to finish them. A new submarine, even of an
older design, was clearly preferable to one, although probably
less than five years old, that had been worn out by a large
number of war patrols. The new submarines, even if of the same
basic design, had other advantages to be considered. Submarine
hulls were now built with an all welded construction with better
steel, which increased their diving depth by fifty feet. They
were also fitted with the new type 267 radar, which was much
more effective against surface targets and they retained the
type 291 air warning set too.
The question
also arose of which of the four current designs of British submarine
it was preferable to keep in the post war fleet. The A-class,
the newest type, had been designed for war against Japan in
the Pacific and, as has been said before in this account, had
the principal characteristics of high surface speed with a good
surface warning radar set to enable them to carry out the night
surface tactics found so successful by the Germans and, above
all, by the Americans. However the A-class design was clearly
going in a very different direction from the Germans with their
Type XXI. The Type XXI had been developed because, when operating
against radar, the night surface tactics had been found to be
ineffective and dangerous. They had therefore produced a submarine
with the accent on submerged rather than surface performance.
With the end of the war, radar was no longer an Allied secret.
Obviously its use for navigation and avoiding collision at sea
demanded that it should be released for use by merchant shipping.
In the future no navy would be without it. There was now no
doubt that the future lay in the German development of the submarine
rather than the American, and that the A-class were too late
to take advantage of a phase of submarine warfare that was already
a thing of the past. The A-class had, however, two qualities
that enhanced their submerged performance over the T, S or U-classes
and these were their diving depth of 500 feet and their long
forty feet periscopes. In addition to Amphion
and Astute,
already completed, another fourteen were in an advanced state
of construction and it was decided to complete them, but to
cancel the remaining twenty-nine that were on the slips or already
ordered. Thirty boats of the T-class survived the war and another
ten were building6.
It was decided to scrap the older worn out boats, and those
such as Terrapin,
which had been seriously damaged, a total of nine altogether.
Six of those building were in an advanced state and were completed,
while four more building were cancelled. The T-class design
anyway gave more weight to its submerged performance than surface
qualities. The schnorkel or snort, had already been fitted in
Truant
for trials and, with engines of moderate power, promised to
be more successful than if put in the A-class. The last six
of the T-class building were all to be fitted with the new type
267 radar and the last of these, Tabard,
was to have a periscopic version that could be used at periscope
depth7.This would
make the night surface torpedo attack obsolete and would replace
it with a submerged attack by radar aided on moonlight nights
by the periscope. It would also make snorkeling at night much
safer as the radar would give warning of the approach of ships.
Whereas the first fitting of snort to British submarines was
at the request of the anti-submarine world, as they wished to
develop countermeasures, it was now seen to be essential from
a pro-submarine point of view. Coupled with the fitting of type
267 radar, which could be used at periscope depth, the result
would be superior to the German U-boats in the inshore campaign
at the end of the war, and would be essential to compete with
efficient, universally fitted radar in ships and aircraft in
the future. The decision was therefore taken during 1946, to
fit snort and type 267 periscopic radar to the whole T-class
and this was later extended to the A-class, and these submarines
formed the operational strength of the British submarine fleet
in the immediate post war years.
The fitting
of snort, although it enabled submarines to remain submerged
at sea all the time and to counter the use of radar by the
enemy, had a price to pay for this advantage. Mobility was
reduced from that of a surface speed of 14 knots or so, to
the snorting speed of 6 knots. Furthermore the snort did nothing
to confer any immunity from attack by asdic, which, with the
new ahead thrown weapons such as the Squid, had become lethal.
For this the answer was high submerged speed and to obtain
this, the British pinned their hopes, at this stage, on the
hydrogen peroxide system gleaned from the Germans, and they
fully intended to proceed with trials with U1407. The
intermediate stage of the Type XXI did not seem important
as time was now available, which it had not been for the Germans,
to develop the hydrogen peroxide system8.
Of the S-class,
forty-seven submarines survived the war9
and another ten were building. Six had already or were
in process of being converted to fast anti-submarine targets
and three of the oldest and one that had been damaged were
scrapped. At the same time, four of those building were cancelled.
This left thirty-seven operational S-class in the post war
fleet, and one of these, Sirdar,
was being fitted with a snort. There were also six fast ant-submarine
target conversions. The U or V-class construction programme
was complete before the Japanese surrendered and this left
a total of 32 boats at the end of the war10.
Two more were transferred to Allied Navies11
and sixteen of the older boats were either scrapped or placed
in reserve awaiting scrapping, leaving fourteen in the post
war fleet.
The above
figures still show a submarine fleet of eighty boats with
another twenty-seven building and this was substantially larger
than the pre-war establishment. The available manpower, however,
would not allow anything like the whole number to be in commission
and many boats would have to be put in reserve. During the
rest of 1945 and the first part of 1946, the post war disposition
took shape. There were fifty-three submarines in commission
by midsummer 1946 in four flotillas, three at home and one
abroad. Two more new A-class, seven T-class and six S-class
had been delivered from the builders and had completed their
trials and working up. The A-class stayed in the Third Flotilla,
but the six new T-class all went out to the Far East to bring
the Fourth Flotilla up to strength and relieve the remaining
boats that had been there since before the war ended. The
new S-class joined the Seventh Flotilla, which was now at
Portland for anti-submarine training duties, replacing submarines
of the U and V-classes, which went into reserve. The S-class
submarines of the Second and Eighth Flotillas, which had been
sent home from the Far East at the end of the war, were also
put into reserve. Altogether there were thirty-seven submarines
in reserve, all being of the S, U or V-classes in five groups
at Lisahally, Gareloch, Holy Loch, Harwich and Portsmouth.
So, after
six years of war, the British submarine fleet returned to
a peacetime posture with no enemy in sight. It is of interest
that it was decided to keep all the larger boats of the A
and T-classes in commission and to relegate most of the small
U and V-classes to reserve. One flotilla of the medium sized
S-class was retained and the rest of these were also put in
reserve. Clearly it was best to have the A or the T-class
with their long endurance in the Fourth Flotilla in the Far
East but it is not so easy to understand why two of the three
home flotillas should also be composed of the A and T-classes
where long range was not so important. The small size of the
S, U and V-classes had been found to be an advantage during
the war and the only explanation is that the fitting of snort
and the periscopic type 267 radar in the smaller submarines
at the time was not thought to be possible. The details of
the first post-war disposition of submarines can be seen in
Appendix XVII. The main change from the prewar organization
is that all three flotillas at home remained under the command
of FO (Submarines) and no flotilla was attached to the Home
Fleet. Submarines for fleet exercises were supplied as required
by the submarine command. The Third Flotilla remained in its
wartime base in the Clyde and continued with its function
of the trials and working up of new and refitted submarines.
It also did the sea-training of Commanding Officers, both
of which had, pre-war, been done in the Fifth Flotilla at
Gosport. The Fifth Flotilla had also resumed other pre-war
duties, notably the training of submarine crews while the
Seventh Flotilla at Portland supplied submarines for anti-submarine
training as before. Here we must leave the subject, as the
post war development of the submarine has no part in this
account, which is to study the operations of British submarines
and their Allies during the Second World War.
