what if germany invaded britain - Sealion

The Germans couldn't have invaded after Dunkirk, due to the fact they didn't have a single plan on how to do it.
The German Military High Command (as well as the Nazi leadership)had simply assumed that the British would seek peace in such a situation. They had totally failed to plan for any other outcome.
They also didn't have the logistical capacity to land a single division at that time, let alone an army.

The vast majority of the German land and Air forces were still fighting French forces at the time of Dunkirk, and after the German victory in France, both the Luftwaffe, and the army needed time to rest and refit.

On the British side while the army was in bad shape, the RAF had over 600 operational Spitfires and Hurricanes, and the RN while it had a number of destroyers damaged at Dunkirk still had more than enough to overwelm any attempt at a landing (even more so, considering the air-cover over 600 fighters could have given it).

Attempting to cross a Channel guarded by the best, and largest navy the world had ever seen at that point.
While it is very true, that if the Germans had gotten their army over the Channel, they would have won. The problem was ( and the Germans quickly realised this when they started to plan for Operation Sealow) they were never going to get enough of it over there. The vast majority of it would have ended up at the bottom of the Channel

[ 11. September 2005, 05:15 PM: Message edited by: redcoat ]

 

Backup a minute Redcoat. The premise of the whole discussion is that the RAF and RN are presumed to be out of the picture. They were a viable and impressive force to be reckoned with and no one doubts that they would have given the huns a thorough bloddying if they tried to cross the channel.

FramerT, once again the premise is that the RN is out of the picture as a viable fighting force. Without the RAF and RN guarding the convoys, the USA and Canada are pretty much out of sight and out of mind. No one has given a time frame but we all seem to be assuming the summer of 1941 when the US was not in the fight yet. If Hitler got into power in England before December 7th then who would the US be allied with to justify them declaring war on Germany? I guess that maybe the British government may have gone to Canada or Australia and continued their fight. They better have brought the Enigma code breaking machines with them though or there would have been a lot more U-boats surfacing and a lot more merchant ships submerging.

I don't think that the Russians would have rolled over the Germans easily if they had no assistance from the west. Recent education by other forum members leads me to believe that another victory in the west by Germany would have kept them content even longer with their pre-war and early war military production levels. This would not have allowed them to stand indefinitely before the mass of the Russians. There would have been more dead Russians and more dead Germans but there would be a lot more red and a lot less white and blue in the French flag after this scenario played out.

 

Weighing in a bit late: I would say, even without any British naval or air interference to Seelöwe the Germans would at BEST get an 'Anzio' type of result and at WORST simply be defeated in attempting to take Britain.
Firstly, we can look at the German invasion plan. They intended to land the first wave on three widely seperated beaches with each being unable to support the other landings. These were:

Folkestone - St. Leonards 26,800 men
Bexhill - Eastbourne 13,400 men
Beachy Head - Brighton 20,100 men

The composition of this landing force was made up from 9 divisions each landing about 6,500 men. 250 tanks were to be landed split between the three beachheads. Very little artillery was put in the first wave each beach receiving about a battalion's worth of guns. The 7th Fallschirmjäger division with about 5,000 men would be parachuted into areas behind the three beach heads giving initially about 500 to 1000 paratroops behind each beach. The reason for this was the entire division could not be dropped in one lift. The Germans lacked the aircraft for that.
There was to be virtually no naval gunfire support available.
Worse yet, judging from the results the Germans had in practice landings, and from US / British experiance in amphibious assaults one could reasonably expect the Germans to lose a good portion of the small number of tanks and cannon trying to get them ashore. The same goes for vehicles, horses and, horse drawn equipment. I would suspect that up to 50% of such equipment would not make it ashore intact.
For landing craft and such, the Germans could reasonably be expected to lose as much as 50% of the initial total through beachings with the craft unable to retract (ie get back off the beach), broachings, wrecks etc. After all, the US lost nearly that in North Africa during Torch using purpose built landing craft.
Add to this the fact that the landing craft crews were virtually ignorant in their operation of these craft. Few were sailors. Very few had any real background to handle a vessel of any sort at sea. The likelyhood of the landings being severly confused and scattered is extremely high.
Add to this the possibility of bad weather which would jepordize the entire fleet, many of the vessels were literally incapable of remaining afloat in any but the calmest sea states, and would certainly have raised losses.
Next, the Germans by their plan required 48 to 96 hours to cross the channel with the invasion fleet. Once off the beaches, the Germans expected to require 72 hours to put the above forces ashore. If we figure things don't go completely smoothly, we are looking at 10 to 15 days to get the first wave ashore after departing port. From there, the remaining invasion fleet would have to return to France to embark the next wave and supplies for the troops already ashore. This would require at least another 4 to 8 days to accomplish with another 2 to 4 day trip across the channel after loading.
Next, assuming the first wave gets ashore and is capable of taking at least one port (say Dover or Folkestowe) the Germans would find that these ports in perfect condition (not a likely thing) are capable of supporting only about 1/3 of the forces ashore in terms of unloading supplies.
With each successive lift of troops the supply situation worsens. Essentially, until the Germans take a large port and can open it to bring in large freighters for supplies they are going to find themselves virtually without the supplies to sustain their troops ashore.
Their rate of build up is excruciatingly slow too. In fact, I would think that they could not even keep up with losses. It is very likely that the troops ashore would find themselves in very desperate conditions almost from the moment of landing.
Note, in all of this I haven't even discussed the British response. Essentially, even without air and naval opposition the Germans lose Seelöwe. The invasion would have been a disaster.

 

I will expose my ignorance of German invasion plans here. You seem to have an abundance of information I have none. You are saying that if the Germans had tried to land an invasion fleet with planning ahead of time and little or no interference from the RN or RAF, that they would have failed. Britain evacuates Dunkirk with private craft and just about anything that floats and the German general staff cannot do as well with months of planning?

I cannot argue your points, like I said I am ignorant about any German invasion plan specifics. It just strikes me odd that they would be so inept. Was the whole invasion of the British Isles just a bluff to try to get the British to sue for peace?

 

This is the danger of 'what if?' - it's easily blurred with 'what was...'

Germany started the war with no firm plans to invade Britain - or indeed, to carry out an amphibious invasion of just about anywhere.

France was not expected to fall as quickly as it did, and Hitler cherished the idea of reaching an 'arrangement' with Britain for a long time.

Invasion plans ( 'Operation Sea Lion' ) were cobbled together hastily ( cutting the bows off Rhine barges ! ) and, although a lot of effort was put into assembling invasion forces in 1940, it was effectively a bluff.

As for preparation, just think how long it took the Allies to prepare for D-Day ( including trial runs at Anzio, Sicily, Tunisia....) and the British had learned a few lessons at Gallipoli in WW1. Hitler was famously uninterested in Naval matters.

1940 Blitzkrieg was about political and Government collapse ( in today's parlance, 'regime change' ), not about long-drawn-out battles.

 

Well, in their months of planning OKH and OKW didn't come up with a decent plan for what to bring troops ashore in. They intended to use modified rhine barges which are highely unstable, have a relatively small capacity and rely on good seas. However they didn't have enough to get the necessary numbers across anyhow.

The damning piece of evidence for me is D-Day itself. The immense amounts of planning, preparation, stockpiling of resorces and so on, not to mention building up overwhelming numbers, and it nearly failed. Invasion from the sea isn't like Blitzkrieg, it's obvious your men are coming, they begin the battle defenseless and even with total air and sea superiority they are going to get a hammering from the ground. I have doubts whether in 1940 the Germans could have successfully invaded, not against the numbers of troops (reguardless of their condition) they would have faced.

 

To my knowledge the sea was totally calm at the time for operation Dynamo which truly helped alot...right? With worse weather the number of men getting over the channel would have decreased dramatically, I think. So just the possible bad weather and improvised German shipping system...not a good choice.

 

The differences between the evacuation at Dunkirk and an amphibious operation like Seelöwe are night and day. These are some of the major differences:

The British had only to evacuate manpower. There was no need for them to be in organized military units or to possess all of their equipment.

The British had ports on both sides of the channel from which to load and unload survivors. This greatly eases the evacuation rate and difficulty.
The Dunkirk survivors were unloaded in ports in England using accomidation ladders while the ship was tied to a pier.

Of the 338,220 troops rescued, the breakdown by vessel is:

5031 in 203 private motor boats
4895 in 27 yachts manned by the RN
28709 in 230 trawlers and drifters (small coastal freight ships)
48472 in 38 large minesweepers (think destroyer / firgate sized)
87910 in 45 transport ships / passenger ferries
102843 in 56 destroyers and motor torpedo boats

The reason the destroyers were so effective was they could load around the clock and operate in daylight as they could defend themselves against air attack. They also had far more speed so could make the round trip faster than the other vessels.
In virtually all of the vessels used, the crew was well versed in seamanship and piloting. They were no amateurs at sailing.

The British had no need to supply these soldiers and maintain their combat effectiveness in Durkirk beyond holding the Germans at bay while evacuating. Thus, with each load taken off, the supply situation became easier to manage.

For the Germans Seelöwe was to use (roughly as the count varies some by source)

170 transports of various size
2000 barges (figures run from about 1800 to 2200)
350 - 400 tugboats (to pull strings of barges as most are unpowered).
1000 or so motor-boats (mostly small outboard types).
The powered barges include a handful of pontoon barges powered by aircraft engines (predicessors of the later Sebel ferry).
The Germans have no purpose built landing craft for beach operations. MFP's and such don't exist yet.
The landing proceedure for a barge (powered) would have been to run it in and onto the beach. The problems involved here are currents and waves on the approach. These could cause the long, shallow bottomed barges to broach (ie turn sideways to the beach) fairly easily. This is particularly true if cross currents or rip tides are present. Getting on the beach itself also involves the beach being suitable for such purpose. Too much gradient and the bow is aground while the stern is still afloat. The danger here in a barge is that wave action will break the back (keel) of the barge and subsequently sink and break up the vessel.
Too little gradient and the barge finds itself grounded well out to sea with the troops having to wade in from some distance. This increases the possiblilty of losing heavy equipment in particular. Motor vehicles may not even be unloadable in such conditions.
Then, comes the problem of unloading itself. Unlike Allied landing craft with powered ramps and purpose built cargo holds etc., the German barges had a precariously steep set of 3 to 5 ramps that are manually deployed over the bow of the barge. This operation takes some time so anything but men with personal small arms are likely to be very slow to unload.
Last, comes retraction from the beach. Once the barge is unloaded, the Germans would need to get it off the beach so it could make a return trip to get more men and supplies. Given the unsuitable nature of the craft, the fact that the Germans knew virtually nothing about the beaches they were to land on...they did not know the beach gradents, composition of soil, off-shore obstacles (both natural and man made), tides, wave heights, wind, etc., the list is quite long...means they were going to be landing on sheer luck as to get their barges ashore intact.
For escorts and firepower during this operation a number of minesweepers and armed trawlers were to be used (the biggest gun on any of these is a 37mm AA gun). The armed trawler described is approxmately: 110 tons displacement, 80 fl long, 20 ft wide 8 - 9 foot draft. One diesel of 105 bhp for 9 knots max. 1200 miles at roughly 7 knots. 1 37mm and 3 to 5 20mm AA guns. These boats had no radar, no searchlights, no specialized naval equipment to speak of either.
To compound these problems the Germans lacked experianced crews. On almost all of the invasion vessels the crew had little or no naval experiance of any kind. Many of the crews had never seen the ocean before being assigned their duties.
As you can see, the invasion fleet itself was primed for disaster even without interference. The OKM staff tried to tell the OKW and army planning staffs their expectations and plans were pure fantasys but neither particularly listened. Had, Seelöwe proceeded, even without British air and naval interference, it would have failed disasterously.

 

I never knew the real depth (shallowness) of the German invasion plans. I read about it in the limited histories I have seen and felt like the British were pretty intimidated by the thought. It seems that if they were it was unwarrented.

Does anyone know if history has any record of the British awareness of the German capabilities in the area? If I knew a hostile government was going to go through with an inept effort like this I would have been sure to find a way to encourage them in their effort. It would have made a handy trap since the RAF and the RN were quite capable forces. Having the Germans virtually hand over 4 divisions of men as well as concentrating another 7 divisions within striking range of the RAF and naval gunfire would have been quite the coop.

 

I'm in Glenrothes, in Fife mate.

 

Those were desperate times and 'hard' intelligence for the retreating British was almost non-existent - in mid-1940, ULTRA and photo-recon were in their infancy. Britain generally believed in the threat of invasion, which is why Bomber Command put a large amount of effort into sinking the massed invasion barges during the Battle of Britain, suffering high casualties in the process. The perceived threat of invasion by airborne forces was also a source of National preoccupation - pre-war Nazi propaganda was remarkably effective.

 

I guess if the German threat of invasion had succeeded to push the British to cease hostilities with the Germans that would have been one of the famous feats of military misdirection.

 

Here is a new twist. Someone said that the initial plans called for four divisions to be inserted. Three by sea and one by air.

What if instead of trying to cross the channel and capturing the ports by sea the Germans had dropped three or four divisions of airborne troops into the country? Would they have been able to secure a harbor or airfield facilities they could have used to more efficiently move troops into the country? I only know a little about the land defences on the British Isles. Would they have been vulnerable to paratroopers landing behind the coastal area and then proceeding back to the coast to capture the coast and port facilities? Would the Luftwaffe have had any chance of protecting a landing zone that was bringing in supplies? Looking at a map of the defense installation locations it looks like the Exeter Taunton area was fairly undefended. Would there be a location that would be feasable for unsupported ground troops to defend against armored counter-attack?

[ 12. September 2005, 02:03 PM: Message edited by: bigiceman ]

 

No one denies that.

But, as Martin said (and has proven it many times), the RAF was far from being destroyed. The Germans were causing bearable damage at unbearable costs. Germany, in autumn 1940, was training fewer pilots and making fewer planes than Britain, and losing many more of both. At that rate there was nothing much they could expect…

'Seelöwe' involved some 9 divisions landing between Dover and Porthsmouth, which means that the 22 km seastrip between Calais and Dover isn't the same in the whole lenght of the front. Thus, the Rhine barges and the Kriegsmarine (still leacking its wounds from Norway and regretting the loss of almost 50% of the German surface fleet) had to cross the Channel in a broad front and at different distances, allowing the Home Fleet to crush German flanks at night.

And what about seaborne invasions without naval superiority? What about Norway and Crete? The Germans failed miserably at sea, defeated by a greater naval power, even if they possessed air superiority.

If the Holy Ghost makes the RAF and RN vanish from the face of the Earth, yes…

But there's still the weather and the Channel, right?

Since when the Germans in WWI and WWII had any sense? Since when Hitler had any sense?

German generals liked fighting difficult and useless battles, no matter how bloody: Tobrouk 1941, Leningrad 1941-1944, Stalingrad 1942-1943, Verdun 1916, I & II Ypres 1914-1915, the Bulge 1944-1945… the list goes on.

Hitler liked putting on a fight for 'important' resources: Swedish iron ore route 1940, Caucasus oilfields 1942, Romanian oil fields 1940-1944, Hungarian oil fields 1945…

That, or either a B-29 carrying 'Little Boy' from Iceland in summer of 45 all the way down to Cologne, Hamburg or Berlin (or from North Africa to Vienna or Munich); or MacArthur, along with Nimitz's ships landing the Marines, first in Ireland, then in Great Britain.

In fact, independently of German coal production, Hitler became obsessed with holding the Dóniets basin, a territory very rich in coal (harrassed by the Soviets in 1941 and unable to produce enough coal to justify its cost successfully when in German hands), which was in the oppossite side of the German defensive line in the river Dóniets. Holding the bridgehead during the Soviet summer and autumn offensives of 1943 costed the Germans thousands and thousands of men.

And we know the Germans treated the arian Dutch very nicely… including the massive famine of 1945, the terror bombing of Rotterdam and brutal anti-partisan activities?

160.000 French died in Nazi concentration camps, as well as 40.000 who died in slave labour. 90.000 were killed by Nazi terror and some 60.000 in bombings of all kinds during the whole war.

200.000 Dutch civilians and 80.000 Belgians too…

Wasn't it the rule in Poland or the USSR?

German planning for 'Seelöwe' only started after Dunkirk, and it could have been launched until the conquest of France and the re-organisation, re-fitting and re-deployment of the Luftwaffe were complete.

And we know it worked so well! (and it was reduced to a heap of ruins by Army Group 'C' alone).

You missed the rest of the Wikipedia text, dear Bish:

In wargames conducted at the Royal Military Academy Sandhurst in 1974, which assumed the Luftwaffe has not yet won air supremacy, the Germans were able to establish a beachhead in England by using a minefield screen in the English Channel. However, after a few days, the Royal Navy was able to cut off supplies to German troops in England, and they were then isolated and forced to surrender.

And it too worked so well at Leningrad…

No. What about most Lend & Lease supplies mostly coming from the land routes of Persia and the Caspian Sea? What about that, by the time Germany was stopped and fatall wounded in the Eastern Front (December 1941), nor the Allied air or land offensive were consuming enough German resources to turn the tide in the East?

True! Great post, Redcoat!

As T. A. accurately mentioned in his supperb post, the Germans didn't have enough transport aircraft to drop not even one division, let alone four! Also, Germany simply didn't have four airborne divisions. In fact, airborne troops losses in Norway and Holland had been severe. I'm sure Red Baron can provide more info on this.

 

Well said Freidrich. I guess that puts this post to bed. What should we talk about now?

 

Yes - well done, Friedrich ; great posting to pull so many threads together !

 

How 'inept' the German army was?