Sealion & Barbarossa
Operation Sea Lion
It Happened Here
Problems with Operation Sealion
There are many reasons to believe that had the Germans attempted Operation
Sealion, perhaps even after gaining air superiority in a different Battle
of Britain, that they operation would have ended in failure. These
Of course, nobody can be absolutely sure what would have happened had the
Germans attempted to invade England, but it does seem like it would
have been an extremely difficult operation.
When one considers all the difficulties that the Germans faced,
it does seem that there was at least some possibility of the invasion
turning into a disaster.
- The Royal Navy was vastly superior the the Kriegsmarine:
British ships available for anti-invasion duties outnumbered the German Navy (Kriegsmarine)
at least 5:1 in every category of large vessel. Additionally, the Royal
Navy had access to many smaller craft such as sloops, minesweepers,
trawlers, etc., that while not particularly useful against warships,
would probably have been able to cause havoc against the Rhine
that the Germans planned to use to transport their landing force.
The standard argument that if the Germans had gained air superiority they
would have been able to sink the British vessels does not really stand
up to much scrutiny. During the Dunkirk evacuation, despite having control of
the air for long periods, and despite the ships spending a lot of time stationary in
the harbour (loading), the Luftwaffe was able to sink only 4 of the
39 Royal Navy destroyers which took place in the operation.
Additionally, the Germans hoped to use submarines and mines to prevent
the Royal Navy from entering the Channel. Even if they had succeeded
with this, the Royal Navy already had 17 destroyers and 3 light cruisers
based within the Channel. The Germans had no real plan for dealing with
these ships, other than that their troops on their
barges should open
fire on any unidentified ships!
HMS Prince of Wales:
- The Luftwaffe was inadequate for the tasks required of it:
The German plan demanded rather a lot from their airforce.
The Luftwaffe was expected to:
- Gain air superiority over the RAF.
- Prevent the Royal Navy from entering the English Channel and interfering
with the invasion barges.
- Act as flying artillery for the German troops in England (who were not
bringing much actual artillery with them).
- Prevent movement of British Army reinforcements by bombing railroad lines.
- Bomb London
to cause a mass exodus of refugees, thus clogging the roads.
The ambitiousness of these goals can be realized when one considers the
fact that the total number of Spitfires and Hurricanes available to the RAF, and
the number of Messerschmitts available to the Luftwaffe, were about equal
(although the Germans didn't realize this at the time) -
and that British were actually producing new fighters more quickly than
the Germans. An additional British advantage is that they
would be mostly flying over home territory (which meant more time in the air,
and a higher chance that pilots who parachuted from their aircraft would be
able to fight again), whereas the Germans would not.
Even if the Germans had managed to achieve air superiority over Southeast
England, that would not have been the end of their troubles. In this
eventuality, the British had plans to withdraw their fighters to the Midlands
where they would have been able to continue the fight out of range of
German fighters. Furthermore, RAF Bomber Command would surely not
have remained inactive, but would most likely have been bombing the German
invasion barges - and defending them from an attack would have been yet
another task for the overstretched Luftwaffe.
- German invasion barges were inadequate:
Lacking purpose-built invasion craft, the Germans planned to use barges
from the Rhine and elsewhere to carry their landing force to England.
However, these craft were flat-bottomed and unsuitable, liable to sink,
in even slightly rough seas: in fact, many of the craft could have been sank
by merely be the wake of passing fast destroyer!
Crewing the barges was also a major problem. The Kriegsmarine
estimated at least 20,000 extra crew would be required to man these barges.
After stripping men from its warships (which surely would have damaged their
operational efficiency), as well as finding every other person with nautical
experience in other military branches, or in civilian life, they were able
to rustle up 16,000: 4,000 less than the minimum required.
German invasion barges being assembled in Boulogne, France:
The Germans concluded that they would be unable to bring heavy equipment
(such as artillery) with them, and would have to improvise. Nevertheless,
since the army used horses for a variety of purposes, they planned to
bring 4,000 horses with the first wave of the invasion fleet. To avoid
the difficulty of loading horses on barges, they planned to place the horses
on rafts towed by the barges (despite the fact that many of the rafts
sank during tests). The barges themselves would be towed by tugs (two barges per tug), at would
take up to 30 hours to cross the Channel.
Even this was not the end of the problems: the Germans planned for the
barges to cross the Channel in columns, then for them to sail parallel
to the coast until in a line formation, and then for the barges to turn again
and advance towards the coast all at the same time. All of this was
supposed to happen at night coordinated by loud hailers, without any rehearsals,
and within insufficient numbers of crew with nautical experience.
- The invasion force was inadequate to defeat the British Army:
While it is true that the British Army was depleted after the debacle in
France, they still had significant forces,
including a fair amount artillery. The Germans on the other hand planned
to bring no artillery with them, and would have struggled to overcome
even antiquated obstacles such as the Royal Military Canal (completed in
1809) or Martello towers (also dating to the early 19th century).
- Resupply would have been problematic:
Obviously the German invasion force would soon be in trouble unless
it could be resupplied. For this purpose, the German's needed to
capture a port, and they decided on Dover. However, the port
was well-defended by the British, and as if to compound their problems,
the Germans planned to make their parachute drop more than 10 miles
(16 kilometers) from the port.
Another way to look at the issue is to realize that
despite years of preparation, historic traditions and recent experiene in amphibious operation,
and overwhelming superiority in the air, at sea, and in numbers of troops,
the Allied invasion of Normandy in
was no walkover. Compare that with an improvised German invasion
of England, with difficulties in the air, at sea, and in terms of ground
equipment, and one has to question what would have happened if Sealion had
Perhaps the most likely scenario is that the Germans would have been
able to land and establish a beachhead, but then find themselves cut
off by the Royal Navy. Inevitably they would eventually run out of supplies
and have no choice but to surrender.
A major wargame that was carried out at Sandhurst in
produced exactly that result.
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