WI: Western Allies Open Second European Front in 1943

The figures on troop and cargo movements are in Ruppenthal Logistical Support of the Armies - I think I download my copy from Boston Public Library. The one other constraint is dock capacity, as they could only work daylight hours (no floodlights in wartime;)).

On troop number, peak monthly arrivals in the UK was 74k in August 1942; this dropped to 53k total for the 6 months November 1942-April 1943, before rising to 174k in November 1943. Certainly getting a million men to the UK by mid 1943 looks possible.

The number of trained divisions is complex, as stripping out cadres for later divisions reduces the training state of the earlier formed divisions. There should be enough trained divisions for a 1943 invasion, although the build up afterwards will be slower.

Shipping capacity is the unknown - as far as anyone can tell there is not an sensible analysis of what shipping might be available if it were not used in the Pacific. Again there is probably enough shipping if Pacific operations were put on hold.

Thank you. That is very interesting. So to summarise:
if we crush the U-boat menace by, say, April 1942, put all troop transports onto the Atlantic run, strip American forces that will arrive too late to support those that will be on time, move Landing ships and landing ship tanks from the Pacific we can get a reasonable force (less than D-day though without Italy the Brits would be stronger too).

Next Question what would the Germans do when they saw this lot coming at them through Calais?
 
To launch an attack on France in 1943 we need to ship more than 1.5 million American troops to Britain (Plus aircraft, tanks, Canadians etc) in less than 18 months. That is an average of about 90,000 per month (historically 20,000 was all that could be sent per month in 1942).

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The above assumes a rapid build up the size of the 1944 OVERLORD Op in 90 days is the goal. If the 90 day & 120 day goals fit what is realistic for 1943 the cargo ship requirement is different.
 
The above assumes a rapid build up the size of the 1944 OVERLORD Op in 90 days is the goal. If the 90 day & 120 day goals fit what is realistic for 1943 the cargo ship requirement is different.
I am sorry, I must be very dim today but I Don't really understand what you are saying.
Do you mean you need fewer troops in 1943? Or do you mean we need less sea lift because there are fewer troops? Or do you mean the whole idea is impossible?
 
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The number of trained divisions is complex, as stripping out cadres for later divisions reduces the training state of the earlier formed divisions. There should be enough trained divisions for a 1943 invasion, although the build up afterwards will be slower.

...

Striping cadres ceased the summer of 1943 when Marshall capped the ground combat division count at 90. It could have been reduced if the dozen Separate Infantry Regiments had been further used to form the last 2-3 Inf Div.

I'll check for details on this.
 
I am sorry, I must be very dim today but I Don't really understand what you are saying.
Do you mean you need fewer troops in 1943? Or do you mean we need less sea lift because there are fewer troops? Or do you mean the whole idea is impossible?

That a less ambitious build up in the first 90 days from the invasion requires less build up previous to the invasion.

I'm away from my references, will put in abstract terms. If the historical OVERLORD Op of 90 days is given a value of '1', then a operation with a goal of placing 60 o/o of that ashore in 90 days requires proportionately less preparatory build up.
 
That a less ambitious build up in the first 90 days from the invasion requires less build up previous to the invasion.

I'm away from my references, will put in abstract terms. If the historical OVERLORD Op of 90 days is given a value of '1', then a operation with a goal of placing 60 o/o of that ashore in 90 days requires proportionately less preparatory build up.

Thank you. I understand that.
I was asking what you thought that implies?
Can the allies invade in 1943 with only 60% of Overlord or will the Germans throw them back?
I am not expecting a detailed analysis I just wonder what your feel is?
 
Can the allies invade in 1943 with only 60% of Overlord or will the Germans throw them back?

The Allies succeeded in Normandy with perhaps less than you think:

https://en.wikipedia.org/wiki/List_of_Allied_forces_in_the_Normandy_Campaign

19 US Divisions, 12 British (plus extra armoured brigades), 3 Canadian, 1 French, 1 Polish which annihilated the German Army in Normandy.

Exact force ratios will depend on what is happening elsewhere, especially in the Mediterranean, but it shouldn't be too difficult to get 30+ Allied divisions for the invasion and Battle of Normandy. What will slow down is the later US buildup - an extra 8 Divisions by October, another 25 by March etc.
 
Thank you. I understand that.
I was asking what you thought that implies?
Can the allies invade in 1943 with only 60% of Overlord or will the Germans throw them back?
I am not expecting a detailed analysis I just wonder what your feel is?

Working out of town & don't have any references at hand. What you want to do is take a look at what the German defense in the west actually was in 1943. Then decide What other actions of 1943 you want to change, including Op TORCH and the Tunisian campaign.

Before you start slashing other campaigns that year note that the Allies were able to make a amphib. assault onto Sicilly that was similar in size to Op NEPTUNE, larger depending on how you count. Inside ten days they had a a army of 11 divisions and five of the Commonwealth independent brigades operating on Sicilly, along with three corps and two army HQ and accompanying support groups for each. I can't say what limit there was on what else they might have been able to send and operate in Sicily. In thirty days the campaign was over & the Allies hit the reset button and executed three more corps and army size amphb ops in the next three months, along with building up a army group in Italy.

...

19 US Divisions, 12 British (plus extra armoured brigades), 3 Canadian, 1 French, 1 Polish which annihilated the German Army in Normandy.

Exact force ratios will depend on what is happening elsewhere, especially in the Mediterranean, but it shouldn't be too difficult to get 30+ Allied divisions for the invasion and Battle of Normandy. What will slow down is the later US buildup - an extra 8 Divisions by October, another 25 by March etc.

Among the potential trade offs to get to that 30 divisions, or 20

Reduce the 1943 offensive in the S Pacific to a holding of diversionary op.

Reduce LL to the USSR.

Reduce LL to China.

Reduce the Tunisian campaign.

Postpone operations against Italy.

Obviously some of these reductions are less desirable than others. The largest & most important savings is in cargo ship space. Reduction of S Pac ops may leave amphib. shipping for a corps or more for use in Europe instead. Have to do a boat by boat count to ferret that out. I don't think its necessary to rely the US Navies central Pacific offensive. That was launched with material allowances laid on back in 1942, started out with a single ground combat corps, & drew only a weeks worth of combat material each month for that corps.. Delay of construction of the fleet train, and Essex class carriers may not help boost much in Europe, at least not on a six or nine month notice.

The other factor that never is defined clearly in at the start of these 1943 invasion discussions is the goal. There is a loose assumption usually in play of reproducing the historical 1944 operation. While the overarching strategic goal was setting up for the final invasion of Germany the core objective of OVERLORD was to create a large lodgment in the Normandy/Breton regions and secure the ports therein. All that was to be done in 90 days & was based on the idea the Germans would not risk destruction of their armies in a forward defense.

I think its unlikely the same levels of combat power can be reached that were available in 1944, but that is true for both sides. If your goal is to create a army group size objective of 20+ divisions ashore in 30-60 days and control substantial port capacity that seems doable in 1943. After that the build up can go directly to France with less interim layover in the UK. It also leaves the amphib fleet free for use elsewhere after the invasion. To paraphrase WGF Jackson it 'ends the tyranny of Overlord'. At least for the amphib fleet.
 
Thank you.
Very interesting. I wonder would you say the Germans will have less forces in 1943, I have always assumed (with no evidence) that the axis powers were weaker in 1944 both absolutely and relatively.
 

Deleted member 1487

Thank you.
Very interesting. I wonder would you say the Germans will have less forces in 1943, I have always assumed (with no evidence) that the axis powers were weaker in 1944 both absolutely and relatively.
They were weaker in 1944 relatively as a whole. The issue is that in 1943 the Front in the East was considerably longer and the Mediterranean theater sucked up the German strategic reserves, so they were relatively more stretched as of 1943; the issue is can the Wallies launch the North Africa/Italian Campaign AND a French campaign. If they can then they can overload the Germans and cause they serious problems in France. But if the Germans opt to hold off on the Kursk campaign then they have a powerful reserve that can be used in France if needed.
 
I suspect if German High Command ( does this mean Hitler in 1943?) saw 20 - 30 divisions in southern England with transport and air support moving into place they will throw everything they can to defend western europe. Antwerp has to be more valuable than Naples or Kursk surely?
 

Deleted member 1487

I suspect if German High Command ( does this mean Hitler in 1943?) saw 20 - 30 divisions in southern England with transport and air support moving into place they will throw everything they can to defend western europe. Antwerp has to be more valuable than Naples or Kursk surely?
Where there enough divisions to invade Italy per OTL plus France in 1943?
 
Thank you.
Very interesting. I wonder would you say the Germans will have less forces in 1943, I have always assumed (with no evidence) that the axis powers were weaker in 1944 both absolutely and relatively.

I was referring specifically to NW Europe, or France & Belgium. Fewer infantry divisions & corps support groups, fewer armored or motor infantry divisions. The air strength was roughly the same in the west, tho that in Germany it self was different. Training was much better in 1944 as fuel and other material were better provided, and command emphasis placed on it from the top. Also fewer trained units were rotated out & sent east. Equipment in the field army was better in 1944 as the battalions were fully fitted out with current kit, vs training allowances of mostly French residue. Last but not least the beaches were effectively not fortified in mid 1943. The program to do so was just starting & the initial steps were to bring the defenses around the ports to the desired level.

The strategy of 1942-43 was to anchor the defense on the ports, denying them to the invader, then build up a counter attack force of a couple field armies inland to run the unsullied defender off. Rommel changed this, in part because of observation of the Sicillian and Italian campaign. He drew the correct conclusion the Allies could supply a entire army across a beach, & through small fishing ports. He also understood the assembly of reserves and build up of a counter attack would be happened by the enemy tactical air support. Hence his forward beach defense strategy.

Where there enough divisions to invade Italy per OTL plus France in 1943?

How large invasions do you want? There was a small amphib fleet in the UK in 1943 COSSACS original OVERLORD plan with only three beaches/corps was based on what a smaller fleet at hand could do. Op HUSKY was huge & could have been reduced considerably if the goal was only a diversionary operation there. Then a single army of 2-3 crops would be sufficient. if you want to wait until late 43 or early 44, after the NW front is well established then it may be desirable to build up a force sufficient to knocking Italy out, or for invading south France. My guess is that Italy will be in such desperate condition by early 1944 its going to ask for terms even if not invaded.
 

Deleted member 1487

How large invasions do you want? There was a small amphib fleet in the UK in 1943 COSSACS original OVERLORD plan with only three beaches/corps was based on what a smaller fleet at hand could do. Op HUSKY was huge & could have been reduced considerably if the goal was only a diversionary operation there. Then a single army of 2-3 crops would be sufficient. if you want to wait until late 43 or early 44, after the NW front is well established then it may be desirable to build up a force sufficient to knocking Italy out, or for invading south France. My guess is that Italy will be in such desperate condition by early 1944 its going to ask for terms even if not invaded.
The issue is if you don't have OTL level of invasion of Italy, then the Germans had extra units to commit to France, especially against a weaker invasion, enhanced by not launching Kursk. The problem with Italy leaving without being invaded is whether the Germans let them defect.
 
The issue is if you don't have OTL level of invasion of Italy, then the Germans had extra units to commit to France,

Many of the units committed to fighting the Allies in Tunisia, Sicilly, or Italy were originally in France. How did they do fighting the Allies in the Med?

especially against a weaker invasion,

..with these German forces being weaker in 1943 as well, particularly if there has been a Tunisian campaign.

enhanced by not launching Kursk.

Why does no one consider the Red Armies plans absent the Kursk battle? They are going to halt offensive operations for the rest of the summer and into the autumn while the Germans send this mass of reinforcement west?

The problem with Italy leaving without being invaded is whether the Germans let them defect.

Either way Italy will be useless as a German ally by the end of 1943. The economy was in tatters, war production bereft with problems.. i.e: declining aluminum stock for aircraft manufacture. i.e.: severe petroleum shortages. i.e.: Loss of food imports from Africa (including French NW Africa). As winter comes on food & fuel shortages will bite. The Germans can occupy Italy & instal a puppet government, they can draw soldiers off the French and Eastern fronts to do that. The Allies can encourage that with deception ops staging a invasion of Italy in the autumn or winter of 43.[/quote][/QUOTE]
 

Deleted member 1487

Many of the units committed to fighting the Allies in Tunisia, Sicilly, or Italy were originally in France. How did they do fighting the Allies in the Med?
Depends on the specific units, situation, and operation you're talking about.

..with these German forces being weaker in 1943 as well, particularly if there has been a Tunisian campaign.
The point is what units are committed where, when, and what changes? Speaking in generalities with this sort of What If, assuming a dual invasion of Italy and France within months of each other in 1943 means we've got to know with specifics to say what would be where, when on the German side of the hill.

Why does no one consider the Red Armies plans absent the Kursk battle? They are going to halt offensive operations for the rest of the summer and into the autumn while the Germans send this mass of reinforcement west?
No, just that if the Germans sit still they will be better off than having attacked; they'd be hit from all sides, but would be in better defensive situations, with better material situations, and in a better position to pull back intact if needed than in a world where they had launched Kursk. Clearly the Russians would attack, the situation is when do the Wallies attack and where, what indications do the Germans have about what is coming and do the Soviets attack early to aid a France invasion? Things would change a lot all around, including whether the Soviets opt to sit still and let the Germans attack first or let the Wallies go first somewhere to suck in the German strategic reserve, a la Bagration. Really it would be more a situation of the Germans not sending reinforcements East for Kursk if already engaged in the west somewhere.

Either way Italy will be useless as a German ally by the end of 1943. The economy was in tatters, war production bereft with problems.. i.e: declining aluminum stock for aircraft manufacture. i.e.: severe petroleum shortages. i.e.: Loss of food imports from Africa (including French NW Africa). As winter comes on food & fuel shortages will bite. The Germans can occupy Italy & instal a puppet government, they can draw soldiers off the French and Eastern fronts to do that. The Allies can encourage that with deception ops staging a invasion of Italy in the autumn or winter of 43.
They wouldn't be useless, but less useful than they were in 1940-42. IOTL the Germans drew off soldiers to occupy Italy and disarm their forces, fight the Allies at the front AND still had more reserves to use in France in 1944 despite the losses of mid-1943 through mid-1944 and a lot more occupation duty to take over without Italy. Having Italy as a going concern, even just for occupation duty would be very helpful compared to OTL, as would having fewer Allies troops to deal with in Italy. Having more problems in France would be a problem, but the Wallies are considerably weaker in mid-1943 when they were in 1944 as well and the Wehrmacht stronger than they were compared to 1944 if you take the situation in the East into account.
 
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