1940: Channel Islands defended

[Magnum]

1.
The only other proper thread on this I could find is this one from 8 years ago, and it mainly deals with a PoD that's way before the British bugged out of France.

2. some background before we get started:

Operation Aerial - Wikipedia

en.wikipedia.org

Beauman Division - Wikipedia

en.wikipedia.org

Norman Force - Wikipedia

en.wikipedia.org

Evacuation of the Polish Army from Saint-Jean-de-Luz - Wikipedia

en.wikipedia.org

Polish Armed Forces in the West - Wikipedia

en.wikipedia.org

4th Infantry Division (Poland) - Wikipedia

en.wikipedia.org

3. reasons for the actual PoD
Churchill decides ITTL to defend the Channel Islands by pulling back a part of the "2nd BEF" towards them, in order to accomplish two goals:

i. force the Germans to delay any operations against Britain by first concentrating against the Channel Islands. Moreover, should the Germans do this, they would be vulnerable to having the Luftwaffe bloodied by having flak concentrated in on specific spot, or having the Kriegsmarine suffer potentially even more losses in light vessels, which they were lacking so much. Thus, even if they were to fall and all men stationed there lost, they would still fulfill their purpose by sufficiently delaying the Germans and causing them losses they could ill afford.

ii. assuming the Germans decide to ignore the islands instead and go full-steam for Sealion, it opens up the supply routes of any potential landings in the center or western part of the front to attacks by British light craft stationed in the Channel Islands, thus allowing a lighter defense of that area and focusing of the limited ground forces available on the eastern part.

(while we know today that Sealion was pretty much doomed to failure, things were not so clear cut in the chaotic days of the collapse of the front in France)

Note: this is NOT a thread about "Britain/Germany could have done better if it did this or that", which usually brings out the Negative Nancys hell-bent on shitting on an idea. Rather, this would be about exploring the effects of a different decision, with good and bad effects for both.

4. What happened OTL
OTL, on the night of June 14th, after efforts to stop the Germans from crossing the Seine had failed, the British decided to pull back from France, although they still dithered on the 15th on exactly WHEN to do so.

Eventually, the following formations were pulled back from the immediate vicinity of the Channel Islands:

Cherbourg (30,630 men):
3rd Armoured Brigade of the 1st Armoured Division
157th (Highland Light Infantry) Brigade
71st Field Regiment R.A. and the Troop Carrying Company of the 52nd (Lowland) Infantry Division
Beauman Division (formerly Line of Communication troops)

Saint Malo (21,474 men)
1st Canadian Division

As artillery, the following was evacuated 120 guns of the 52nd (Lowland) Division from Cherbourg, 24 of the 1st Canadian Division from Brest and 32 guns of the Beauman Division from Cherbourg.

5. How this will take place ITTL
A lot of the small ships that participated in Operations Dynamo and Cycle are sent to Cherbourg and Saint Malo. There, they pick up a lot of the infantry of the above formation (except for the 3rd Armoured Brigade and 1st Canadian Division, which head straight for England) and ferry them to Jersey and Guernsey. This allows the regular transports to focus on picking up more of the equipment that was lost OTL. Some of the guns are also sent to the Islands instead of Plymouth. The Beauman Division was disbanded following its evacuation, so keeping it together here isn't much of a loss for Britain.

Later on, some of the Polish forces evacuated from France, which were never utilized during the war, are also sent to reinforce the Channel Islands, on the same view that they would be more or less expendable.
Polish Independent Highland Brigade - 3000 men
Polish 4th Infantry Division - 3500 men

During and after all of this, all civilians on the Channel Islands not essential to the war effort are evacuated, in order to have less mouths to feed.


Thus, by the time the Germans had France secured by late June, you have around 32.000 men, at most, defending the Channel Islands.

6. German response
OTL, the Germans planned to invade the islands mostly for propaganda purposes, preparing 2 battalions for this:

German occupation of the Channel Islands - Wikipedia

en.wikipedia.org

ITTL, the flurry of activity surrounding them would probably make them reconsider sending only such a small force.

To what extent would this forward British outpost make Hitler alter his plans? Could we see a divisional-sized landing effort preceded by an intensive bombing campaign undertaken at the expense of operations over the Channel or over Britain (Kanalkampf, Adlertag etc.). Would such efforts be successful, or could the British counter them by, say, sending out a force of expendable destroyers and other light craft as soon as the invasion starts?

 

[Anarch King of Dipsodes]

It's an interesting idea. 32,000 men is probably not enough to defeat German invasion, but it would definitely require a significant diversion of German troops and air power.

German amphibious moves against the islands could be attacked by aircraft from Britain, forcing the Luftwaffe to commit escorts to cover. There would be an attrition battle over the islands. This however would be on much less favorable terms for the RAF than the OTL Battle of Britain, and at this time the RAF couldn't afford it.

Another point: the Germans could take the islands one at a time. Thus the British forces would be "defeated in detail".

The campaign would take about two months to prepare and execute, so it would not actually delay the Battle of Britain very much. The RAF would be weaker, the Gerrmans would have suffered minor losses but gained some experience in amphibious ops, and the British would lose some valuable troops and equipment.

The German victory would be demoralizing to Britain, unless there was some spectacular last-stand fight.

Overall, I think the results would be negative for Britain.

An alternative: defend only Guernsey. Put all 32,000 troops there, and it becomes a "hard nut", I think. It's closer to Britain, and therefore more favorable to the RAF; also easier to resupply, reinforce, evacuate wounded, etc.

 

[Galba Otho Vitelius]

This is well researched, but it does't change the strategic value of the islands, which was nil, and in fact Hitler and the Germans are usually criticized for bothering to garrison them. If something like Sealion had been attempted, the landing sites would have been well to the east, since landing sites as close to Pas de Calais as possible were the only locations the Germans had even a slim chance of supporting.

 

[BlackDragon98]

Channel Islands become a massive target for large caliber German artillery guns.
If the RN can't maintain a supply line those troops are screwed.
They don't have the time or resource to construct fortifications either, all the fortifications are concentration on the mainland.
Those troops are going to be lost in the end, unless the UK is determined to defend those islands.
Germans get some practice in amphib ops, lose some men. Goebbels is probably screaming his head off on the radio about the victory.


OTL the Germans made a huge mistake putting so much materials, manpower, and effort into those puny islands.
Best choice would be to make a deal with the UK and trade the civilians on the Channel Islands for interned Germans or POWs.
Then mine the beaches and maybe put a radar installation or 2 on the island, along with some flak.
Whole thing needs only around 1000 men because of preexisting fortifications and the terrain.
Establish some gardens and some agriculture on the island so the troops don't have to rely on supplies from the mainland. Probably bring over some chicken and hogs for eggs and bratwurst.
Knowing soldiers back then, they'll probably establish a brothel as well.
Most interesting activity for German soldiers on the island is probably to sit on a small boat and go fishing. Watch the Luftwaffe planes fly overhead now and then.
Absolute boredom until the UK order a commando raid on the island. Mines explode on the beach and then commandos retreat when they realize the whole beach is mined and there's no way in.

 

[Magnum]

It's an interesting idea. 32,000 men is probably not enough to defeat German invasion, but it would definitely require a significant diversion of German troops and air power.

German amphibious moves against the islands could be attacked by aircraft from Britain, forcing the Luftwaffe to commit escorts to cover. There would be an attrition battle over the islands. This however would be on much less favorable terms for the RAF than the OTL Battle of Britain, and at this time the RAF couldn't afford it.

Another point: the Germans could take the islands one at a time. Thus the British forces would be "defeated in detail".

The campaign would take about two months to prepare and execute, so it would not actually delay the Battle of Britain very much. The RAF would be weaker, the Gerrmans would have suffered minor losses but gained some experience in amphibious ops, and the British would lose some valuable troops and equipment.

The German victory would be demoralizing to Britain, unless there was some spectacular last-stand fight.

Overall, I think the results would be negative for Britain.

An alternative: defend only Guernsey. Put all 32,000 troops there, and it becomes a "hard nut", I think. It's closer to Britain, and therefore more favorable to the RAF; also easier to resupply, reinforce, evacuate wounded, etc.

looking at a map of the islands, Jersey certainly looks the most vulnerable, with relatively wide beaches. On the plus side, it's basically shaped like a Vauban fortress, making almost every beach a killing field where the enemy would be receiving incoming fire from three sides.

Guernsey is like that, but ten times more. South side appears to be entirely cliffs. East side is mostly urban and the approach to it is covered by the tiny Herm and Sark. Especially the latter is like a mini-fortress, which would be basically impregnable except by glider attack. This leaves only the north-west side, which has more edges than one can count. Just look at it: https://www.google.ro/maps/@49.463188,-2.6306035,6208m/data=!3m1!1e3?hl=en

So yes, I agree that concentrating on Guernsey would be beneficial. That said, if the objective is merely to slow down the Germans, with the full expectation that troops there would be lost, then I wonder if they would also try to defend Jersey.

Having the RAF contest the skies above the islands would be foolhardy IMO. If this becomes a contest of willpower though ala Stalingrad, then who knows what Churchill would be capable of

Lastly, if they really wanted to, the British could put much more than 32k men there. Cherbourg+St.Malo alone accounted for 52k men evacuated. I doubt though that they would risk the 1st Canadian Division. Who knows...

This is well researched, but it does't change the strategic value of the islands, which was nil, and in fact Hitler and the Germans are usually criticized for bothering to garrison them. If something like Sealion had been attempted, the landing sites would have been well to the east, since landing sites as close to Pas de Calais as possible were the only locations the Germans had even a slim chance of supporting.

With hindsight, we know Sealion would almost certainly have not been attempted. However, the British didn't know that, and neither could they be certain it would only take place close to Dover. In fact, the Germans themselves planned, in their initial draft, to transport 6th Army from Cherbourg to Lyme Regis in the far west, something the existence of an enemy base on the Islands sitting on their flank would complicate.

 

[BlackDragon98]

looking at a map of the islands, Jersey certainly looks the most vulnerable, with relatively wide beaches. On the plus side, it's basically shaped like a Vauban fortress, making almost every beach a killing field where the enemy would be receiving incoming fire from three sides.

Guernsey is like that, but ten times more. South side appears to be entirely cliffs. East side is mostly urban and the approach to it is covered by the tiny Herm and Sark. Especially the latter is like a mini-fortress, which would be basically impregnable except by glider attack. This leaves only the north-west side, which has more edges than one can count. Just look at it: https://www.google.ro/maps/@49.463188,-2.6306035,6208m/data=!3m1!1e3?hl=en

So yes, I agree that concentrating on Guernsey would be beneficial. That said, if the objective is merely to slow down the Germans, with the full expectation that troops there would be lost, then I wonder if they would also try to defend Jersey.

Having the RAF contest the skies above the islands would be foolhardy IMO. If this becomes a contest of willpower though ala Stalingrad, then who knows what Churchill would be capable of

Lastly, if they really wanted to, the British could put much more than 32k men there. Cherbourg+St.Malo alone accounted for 52k men evacuated. I doubt though that they would risk the 1st Canadian Division. Who knows...


With hindsight, we know Sealion would almost certainly have not been attempted. However, the British didn't know that, and neither could they be certain it would only take place close to Dover. In fact, the Germans themselves planned, in their initial draft, to transport 6th Army from Cherbourg to Lyme Regis in the far west, something the existence of an enemy base on the Islands sitting on their flank would complicate.

If the 1st Canadian Division was sent to Guernsey, then their last stand might enter Canadian history much like OTL Dieppe and Vimy Ridge is today.
I recall in high school history there was plenty of droning from our history teacher about Dieppe and Vimy Ridge. Almost nothing about Hong Kong though, which kind of annoyed me.

 

[Magnum]

If the 1st Canadian Division was sent to Guernsey, then their last stand might enter Canadian history much like OTL Dieppe and Vimy Ridge is today.
I recall in high school history there was plenty of droning from our history teacher about Dieppe and Vimy Ridge. Almost nothing about Hong Kong though, which kind of annoyed me.

That of course depends if the Germans manage to actually defeat them of course. If they try and fail, it's possible the 1st Can. Div. would be lionized to no end

 

[Magnum]

One interesting tidbit I found:

During WW1, the Russians were building a dreadnought in the Black Sea, named Imperator Aleksandr III, with 305mm guns. With delays hampering her construction, she only began sea trials towards the very end of Russian participation in the war, after the February Revolution, by which time she had been renamed Volia (Freedom).

On May 1st 1918, she sailed from her base at Sevastopol to Novorossiysk, to avoid capture by the advancing Germans. Once there, she received an order to scuttle on June 19th, but her crew voted 933 to 640 to ignore the order and return to Sevastopol.

Once there, she was captured by the Germans, given a German crew, and began sea trials again, making one brief voyage. Less than month later, Germany had signed the Armistice, and the British Navy arrived to take custody of her.

Now with a British crew, the ship sailed to Turkey, and then back to Sevastopol, where she was gifted to the White Russians, who renamed her General Alekseyev.

With only 3 guns operational, the White Russians used her for shore bombardment, and then when they finally collapsed, to evacuate general Wrangel and his army from Crimea, sailing to Bizerta in French Tunisia.

Once there, the French interred her, refusing to give her to eithwr the White Russians in Siberia or to the Soviets. She was sold for scrap in the 1920s to pay for her "docking fees", but not actually broken up till 1936.

Her guns had been put in storage, but when the Finns offered to buy them in the summer of '39, the French refused, only to give them to Finland for free in January 1940, to help them out in the Winter War.

4 of the guns didn't actually make it to Finland, and were stuck on a transport ship in Narvik, Norway when Germany invaded that country, capturing them in the process.

The Germans then modified the captured guns, and used them in a battery on the island of Guernsey, with a range of 51km.

 

[Raferty]

The Germans could almost certainly place the islands under land based artillery bombardment with rail based guns or other long range artillery, and this I think would make even a concentrated defense of Guernsey difficult to manage. I am not sure to what extent they had amphibious landing capabilities for such a battle, but I would imagine if the RAF tried to contest the skies it would not end well for the RAF.

If a defense of all islands was attempted, I could see defeat in detail as quite possible.

The problem I guess is tactically, how would the Germans approach their disposition of deployments? Paratroopers would likely be a disaster, and the German Army in 1940 had a lot of poorly equipped reserve divisions in its standard order of battle that may not perform well in an amphibious landing, and these were amongst the forces assigned to Brittany and Normandy after the invasion was complete.

 

[Magnum]

The Germans could almost certainly place the islands under land based artillery bombardment with rail based guns or other long range artillery,

hmm, now that's quite an interesting scenario.
Let me see what I can research on the topic - though I gather there are people far more knowledgeable on the technical minutiae of extreme long-range ww2 German guns

 

[Raferty]

hmm, now that's quite an interesting scenario.
Let me see what I can research on the topic - though I gather there are people far more knowledgeable on the technical minutiae of extreme long-range ww2 German guns

We know that they were able to bombard Kent from the Calais region using the K12 (an update on the old Paris Gun). In terms of more effective artillery, I would imagine that they would need a way to fire more rapidly. Perhaps a higher concentration of rail guns in the region. I am not sure on if they could use field artillery against islands from Normandy or Brittany, but I would imagine if they took some of the smaller islands first, they could employ field artillery onto the islands and use that against Jersey or Guernsey.

 

[BlackDragon98]

We know that they were able to bombard Kent from the Calais region using the K12 (an update on the old Paris Gun). In terms of more effective artillery, I would imagine that they would need a way to fire more rapidly. Perhaps a higher concentration of rail guns in the region. I am not sure on if they could use field artillery against islands from Normandy or Brittany, but I would imagine if they took some of the smaller islands first, they could employ field artillery onto the islands and use that against Jersey or Guernsey.

Hitler might order the Gustav hauled up to Northern France and then used against the Channel Islands.
Absolute devastation, though it would become a massive target for the RAF.

 

[Scott Washburn]

Supplying a major force on the islands would be a huge challenge with the Germans able to base aircraft so close to them.

 

[Raferty]

Supplying a major force on the islands would be a huge challenge with the Germans able to base aircraft so close to them.

The Japanese were able to supply the garrison of Rabaul, which numbered over 100,000, using submarines, for the duration of the war. I think the Royal Navy could do the same. Supply of heavier weapons, however, may prove difficult, I would agree with that.

 

[marathag]

We know that they were able to bombard Kent from the Calais region using the K12 (an update on the old Paris Gun). In terms of more effective artillery, I would imagine that they would need a way to fire more rapidly. Perhaps a higher concentration of rail guns in the region. I am not sure on if they could use field artillery against islands from Normandy or Brittany, but I would imagine if they took some of the smaller islands first, they could employ field artillery onto the islands and use that against Jersey or Guernsey.

Would be able to hit the island, sure, but too inaccurate for real targeting.

 

[marathag]

Hitler might order the Gustav hauled up to Northern France and then used against the Channel Islands.
Absolute devastation, though it would become a massive target for the RAF.

Not Ready until December 1941, and will take one month to be made ready to fire, within 37km of the target.

Bomber Command would have a field day

 

[Magnum]

Sark is basically one giant cliff, which I really don't see how the Germans can land on in order to deploy field artillery. Everything else is too far to help

Not Ready until December 1941, and will take one month to be made ready to fire, within 37km of the target.

Bomber Command would have a field day

huh. that means it's basically out of range. Shortest point between a beach on Guernesey and the mainladn is 45km.

As far as I can tell, these 4 would be in range

Todt Battery - Wikipedia

en.wikipedia.org

as would these

40.6 cm SK C/34 gun - Wikipedia

en.wikipedia.org

though barely.

Wouldn't they be really worn out after such continuous use though?

 

[marathag]

Wouldn't they be really worn out after such continuous use though?

most Naval Rifles were good for 3-500 rounds before relining the tubes was required

 

[Magnum]

most Naval Rifles were good for 3-500 rounds before relining the tubes was required

What do you reckon? Can Guernsey be held?

 

[Cryhavoc101]

What do you reckon? Can Guernsey be held?

I really do not see the point beyond it looking good in the morning papers

But then I don't see the point in trying to hold Hong Kong either!