"Paul Sturrock" <
pstu...@gmail.com> wrote in message
news:aa4829fa-08bd-4b85...@googlegroups.com...
> What if FDR -- shortly after the Gilbert and Marshall islands campaign --
> ordered Nimitz to seize Antwerp and the Scheldt estuary? This would mean
> abandoning the Marianas campaign and B-29 raids on Japan (at least from
> the Central Pacific).
This would mean Nimitz was operating to a very different timetable
to Eisenhower.
The final plan Overlord had a 30 day pause for logistic reasons at the
D+90 line, the Seine, since it was expected that only 12 US divisions
could be supported at the river at D+90 and a 12 division assault would
be the first assault across the river. These plans had been made late,
"even dangerously so from a logistical point of view".
> Nimitz is ordered to move his forces, as secretly as possible, to the
> North
> Sea or English Channel by early August at the latest, and rapidly conduct
> an amphibious assault on the Scheldt estuary in concert with U.S. and
> British airborne divisions.
>
> No one in the ETO is told about the upcoming assault, and the Normandy
> landings and campaign take place as scheduled. Airborne units in Britain
> are ordered to prepare for a big operation to take place around the
> projected
> date of the Scheldt estuary landings. Only a handful of officers in the
> airborne and troop carrier units are told about the real target, and not
> until a
> week or two before Nimitz' forces arrive.
>
> The fleet will not make landfall -- unless it can be done secretly --
> until
> it reaches the Scheldt estuary. Something akin to Task Group 50.17, with
> its 24 oilers, 3 hospital ships and numerous escorts will accompany the
> invasion fleet.
So a fleet train and assault fleet plus the carrier forces all trying to fit
into the southern North Sea.
Note the port capacity and internal transport systems of Britain
were highly stressed in the summer of 1944, trying to import enough
to support the local economy and military while exporting two army
groups with full air support to France and keeping them supplied.
Adding the USN carrier fleet alone would cause major problems.
Fuel in bulk, the need to set up replacement aircraft pools and so on.
> The fleet has two routes that avoid the Panama Canal (in order to maintain
> the element of surprise): Either rounding the Horn, with its awful
> conditions, or cruising far to the south in the Indian Ocean on a westerly
> course, passing beneath the Cape of Good Hope into the Atlantic. It takes
> 38 days at 15 knots to go from Pearl Harbor to Antwerp via the Horn, and
> 47
> days via the Indian Ocean.
Now effectively double that for the support ships and understand all ships
would need resupply of food etc. for the crews in the Atlantic, plus fuel.
before any operations could start. Think about how fit the troops would
be after months at sea.
Simply put the deployments would be noticed, starting with the negative
that the axis had lost track of them.
> The Antwerp invasion fleet departs Pearl Harbor on June 5, 1944, the same
> date on which the invasion fleet for Saipan set out.
>
> At Nimitz' disposal are the same forces used at Saipan and the Battle of
> the
> Philippine Sea, including the V Amphibious Corps and the Fifth Fleet. As
> best as I can determine, the following forces took part in the Saipan and
> Philippine Sea battles:
>
> 7 fleet carriers, 8 light carriers, 7 escort carriers
> 956 carrier-based aircraft
According to Max Hastings for Overlord the allied air forces in
Britain had some 9,901 fighters and bombers. Then add the
transports and Coastal Command.
> 15 battleships, 8 heavy cruisers, 13 light cruisers 58 destroyers
IJN end May 1944, including under repair, 3 fleet, 7 light fleet, 4 escort
carriers, 9 battleships,14 heavy and 16 light cruisers, 44 modern
destroyers.
June to December 1944 the IJN added 4 carriers, counting Shinano.
The allied positions in the Pacific, even in New Guinea, were effectively
isolated garrisons that were vulnerable to interdiction. The removal of
the 5th fleet means the IJN have naval superiority. The allies halt or even
start to go backwards.
The size of the suitable airstrip locations meant the land based air
forces at any given garrison could be overwhelmed by the enemy
carrier fleet turning up. That started to change as the fighting
neared Asia.
The USAAF strength, including reserves and second line combat
types, deployed from Alaska through the Pacific to Burma came
to 6,421 end May 1944, the European theater, read Britain, held
10,637, the Mediterranean held 4,828.
Pacific Ocean areas 824 aircraft, Solomons and New Guinea
(Far East Air Forces) 3,403, China/Burma/India 1,776, Alaska
256. Plus 162 aircraft of the 20th Air Force in India. Note these
figures include 901 transports, 51 trainers and 369 communications
aircraft.
If you use the Max Hastings figures the nominal 7,834 front line
USAAF combat types present in Britain in May 1944 gave a
US combat strength of 5,061. Note Hastings's 9,901 allied combat
aircraft strength meant an effective strength of 7,774, or 78%.
To put it another way about half the USAAF aircraft strength in
Britain in May/June 1944 was first line in a combat unit and
able to fly.
The Far East Air Forces end May 1944 had 2,456 first line combat
types from Guadalcanal to Darwin. Then add the allied air forces.
> 37 troop transports, 11 cargo ships, 5 LSDs, 47 LSTs, 10 APDs
> 185 DUKWs, 300-415 LVTs.
>
> 2 reinforced Marine divisions
> 1 reinforced Army infantry division
> Note: one additional reinforced Marine division and one additional
> reinforced Army division were used for the Tinian assault
As of end May 1944 the US military still had 44 divisions still in the
US, including 1 Marine, end August it was down to 32 divisions,
including 2 Marine.
The US units in the Pacific were set up to handle attacking dug in
infantry on isolated battlefields, not a continent with panzer armies
available for counter attacks.
All up the US had deployed 23 divisions in the Pacific to end May.
> About 250,000 men were in the Seabees at war's end; perhaps
> 50,000-100,000 could be allocated in mid-1944 for the rehabilitation
> and operation of Antwerp's port facilities after its seizure. Perhaps
> nearby Rotterdam will also be captured and require the Seabees'
> expertise.
The port capacity to land the troops to capture, hold and repair the
ports was actually a problem in France. Also given how badly wrecked
many of the northern French ports the allies captured unless Antwerp is
taken with days the prize will be lost.
> At least five Allied airborne divisions were available in the ETO around
> this time.
The divisions used in Normandy were to an extent still refitting, the
reality is the air transport lift could not handle 5 divisions. Hence the
multiple lifts for Market-Garden, which was a nominal 3 division
assault, similar for Overlord.
The US 17th Airborne division officially arrived in Britain in August.
> England and its airfields are nearby to provide additional air support;
> London is 200 miles from Antwerp.
Essentially the 5th fleet was limited to a strike radius of 200 miles and
did not have the sea room to operate in the North Sea. Draw an arc
say 150 miles from Antwerp and see how much ocean there is.
> The Battle of the Scheldt provides us with detailed information on German
> defenses in the estuary, which should give us some idea of how an
> enormous amphibious/airborne assault would fare.
Weeks of heavy bomber air strikes on Walcheren, the need to clear
the various river defences. The lack of suitable beaches for a
multi division assault. For around 40 miles north of Scheldt estuary,
to the Hook of Holland, you are effectively assaulting islands with only
a small number of bridges connecting them to other islands or the
mainland, and you start the best part of 50 miles from Antwerp, even
coming ashore around Zeebrugge and Ostend leaves you 50 miles
to go.
> Antwerp is only 134 miles from Dortmund in the eastern Ruhr. Once
> Antwerp is captured and open to cargo ships, the Ruhr becomes
> vulnerable to envelopment, which would spell the end for Germany.
Essentially once Antwerp was open alongside the other Atlantic
and Mediterranean ports the allies could finally funnel in all the forces
they had plus supply them. Then comes actually shipping the forces.
To end September 1944 the US deployed 32 divisions in France,
that is after the southern landings, out of the peak of 61 divisions.
It took until the end of January 1945 for the last of the US army
divisions to leave Britain (2 infantry, 1 armoured).
The only thing the Pacific could supply to the European theatre
that would really make a difference was assault shipping, either
to speed up/increase the size or build up in Normandy or to enable
the southern landings to happen earlier and/or bigger.
Moving land forces from one side of the world to the other makes
little sense when plenty of other forces were available in the US.
Moving the main USN fleet from the Pacific hands the initiative
back to the IJN. Trying to take the Marianas 6 months after the
historical invasions would mean more and better trained Japanese
defenders.
Geoffrey Sinclair
Remove the nb for email.