Operation Sealion Should Have Happened

I started this thread and I'm going to finish it or at least state my closing statement. Hitler believed England would ally with him, he never thought he would be fighting them, that threw a huge monkey wrench in his plans. They even made Nazi/British friendship badges!

 

True enough, but it would have taken the Germans years to do so. First they would have to procure proper landing craft then practice using them on a large scale along with developing loading and unloading procedures for their shipping, command and control, and a plethoria of other things before becoming proficent at amphibious assaults.

The first problem for the Germans here is that the majority of the major French fleet units are not accessable to them. Most are in North African ports. The only major fleet unit in France is the battlecruiser Strassbourg and her crew scuttled the ship when the Germans historically tried to take her. The Germans and Italians both made half hearted attempts at salvage but made no serious attempt to raise, let alone repair, her.
Basically, the Germans got nothing bigger than a frigate from the French Navy as a prize. This is not going to change.
A sustained air campaign might work if the Luftwaffe manages to get some leadership that understands how to manage an aerial campaign of attrition along with finding sufficent fuel to sustain it. But, this will take the Germans years to accomplish and is likely never to be fully successful on its own.

In 1940 there was not Pacific campaign. The Pacific war would not start for nearly a year and a half unless you are talking about things like the occasional clash between Japan and Russia or the war in China. None of these would give much useful data to build on.

Basically, so long as Germany does not possess a navy, cannot achieve aerial superiority (unlikely), and cannot cut England's supply lines (almost certain to draw the US into the war) they cannot successfully manage an invasion after July 1940. Its that simple.

 

can we put this thread to bed?

 

You can try, but I've found that with Sealion threads they keep getting up and then wander around asking for glasses of water.

 

I agree in saying...Sealion would have resulted in Carnage for the Germans...The remnants of the BEF, the rest of the Army, the Home guard and Most of the British population fighting back, RAF bombs and Bullets, and the RN pounding the ships as they come in, and their supply lines would have been jointly savaged by the RAF and RN.
Thats it, end of story, the end, thread closed.

 

With what, my readings of the British failed missions in both French/Low Countries and Norway resulted in the loss of something like 40,000 pows or more, 70,000 vehicles lost 1,000's of artillery pieces lost/captured/destroyed and 1 million tonnes of supplies now in German hands, the British lost something like 400 vessels of all kinds and 100's of aircraft lost and would take at least 18 months to recover, no, Britain was in a far worse situation than what was told to the population at the time, If Germany had a larger amphibious force, Britain im humble opinion would not be able to fend of a German invasion, yeah it would be very costly, but the ends justifies the means, also mentioned local volunteers, I can assure any LDV units that took up arms against any German would be considered Geurilla's and be treated just like any partisan force and if captured instant execution.

 

Kind of like Zombies ? LOL

 

But will it stay there? LOL MMMMMMMMM....... ZOOOOOMMMMMBBBBIIIEEE thread !

 

I think once folks start entering Zombie remarks have obviously nothing further to add to this thread, or just being annoying (although funny) i beleive that this thread should be closed.

 

Sorry for being annoying. Not lol. But This subject keeps coming up as the ultimate "What If?" . There really isn't nothing new to add to this.And It has been rehashed over and over again. Hence the Zombie comment. It just wont Die. The Germans just did not have the resources nor the Naval and Air superiority to accomplish this and even if they did land they would have failed. The RAF and RN would have ravished the Germans attempts to supply a force on the land. Even the wargame at Sandhurst came out that way.

 

You raise the issue of the wargames at Sandhurst, did the wargames take into consideration of British 40,000 POW's in German hands at the time, or that the British Army was without 65 to 70 thousand vehicles short, that 1,000's of artillery pieces and 10's of thousands of other weapons were left in Europe, did the war games consider the 1 million tonnes of equipment and supplies in Europe and the estimated time to replace all this would take 18 months, did the wargames take into consideration of the 400 vessles sunk in Operation Dynamo, did the wargames take into consideration of the loss of aircraft in Europe/Norwegian campaigns. Also did the wargames take into consideration of the executions that the German military would have done on LDV units once ashore and handing out German justice. The wargames i have read about never took any of these main factors in what effect that the rammifications of the failed European/Norwegian campaigns had on the British Army, i would like to see wargames with these impotions imposed on the defenders.

 

Why Operation Sealion Wouldn't Work

The Second World War has always been a favorite stomping ground of alternate historians, especially the writers of alternate history novels. Probably the most popular single alternate history in the western world is one where the Nazis win the war. In order to accomplish this, the creators of many timelines utilize Operation Sealion, a German plan in 1940 for the invasion of Britain. Unfortunately, what most don't realize is that Sealion was nothing more than a pipe dream - utterly unworkable in any alternate history at all similar to the history we are familiar with. In this essay, I will examine the various reasons why Operation Sealion would not work, and could not be made to work (without _extremely_ large changes) in an alternate timeline. Check out my own Unification timeline for an example of the level of changes necessary for a German invasion of Britain to succeed.

There are both practical and political reasons against the success of Sealion. First, I will deal with the political reasons. Mainly, an invasion of Britain was something that would require a lot of planning well in advance to have a real chance to succeed. Since the main window of opportunity is early in the war, before Britain is too heavily defended, the Germans would have to plan for an invasion of Britain as a serious possibility before they even started the war with Poland in 1939. The problem with this is that Hitler never planned for a long term war with Britain, much less an invasion of it. When he invaded Poland, he seriously did not expect Britain to be willing to engage in a full-scale war over it. He kept hoping for peace throughout the early stages of the war, and after the fall of France, Hitler expected to be able to make a peace treaty with Britain so that he could attack Russia. He actually respected the British Empire, and is not known to have ever seriosly considered conquering it as an end in itself. Even if he changes his mind about this after the war is started, by that time it is too late to make all of the necessary preparations for an invasion. Despite his war with the Western Allies, Hitler's primary goal was always expansion to the East (especially the invasion of Russia), and it would require a serious change to his personality for him to distract himself with long-term war plans focused in the other direction.

The second political concern is that Hitler underestimated Britain and Russia. He knew that focusing his entire war effort on Britain would seriously delay his invasion of Russia, because he could not overwhelm both enemies at once. Russia was both his primary goal, and his most powerful enemy. Britain in 1940, and in 1941 when Hitler invaded Russia, was incapable of significant action against Germany. It had been pushed out of Europe, lost much of its army, its air force was capable of only limited bombing raids against Germany, and it was fighting to retain its possessions in North Africa. The US had not yet joined the war, there was little reason to expect it would do so soon, and Britain alone would not be a threat to Germany's conquests for many years. Hitler fully expected to launch his invasion of Russia, fight there for a couple of years at most, and complete the conquest of his last major land enemy before Britain could do anything against him. Thus even if Hitler had been capable of an invasion of Britain, there is a significant chance that he would choose to attack Russia instead, expecting to win there and deal with the British later. Hitler cannot predict that the US will join the war, and without significant change to his knowledge and thought processes, believes that Russia will be defeated within a couple of years.

The political reasons explain why Hitler did not really want to invade Britain. The practical reasons, however, are even more important - they are why he could not hope to successfully invade Britain even if he wanted to. There are four factors which are either absolutely necessary, or extremely important, to an amphibious invasion, none of which Germany possessed. They are the ability to transport a sufficient invasion force to the landing zone, the ability to supply that force once it has landed, air superiority, and the ability to protect the invasion force and its supply lines from enemy naval attack. Of course you must also possess an army to send across, but Germany had no shortage of armies.

First, the ability to transport an invasion force across the English Channel requires landing craft, and lots of them. Germany had very few, and they were of very poor quality. Plans for Sealion involved using Rhine river barges for transport across the Channel. The problem with these was that they were not designed for use in the ocean, and would swamp if exposed to anything but the very mildest weather (or if a large ship passed close to them at high speed). Even if this were not a problem, there simply were not very many of them. The Germans estimated that they had sufficient craft to ship across an invasion force of at most ten divisions. Ten infantry divisions, because without proper landing craft, heavy weapons such as artillery and tanks could only be transported with extreme difficulty. The "best" scheme the Germans could come up with was shipping across tanks on barges, one to a barge, and having them shoot off the front end of the barge so that they could exit it at the landing zone - a method virtually guaranteed to lead to a high rate of failures of tanks attempting to land.

Without a major addition to their landing craft fleet, which would take a great deal of time to build and would be very obvious to the rest of the world, the Germans could not hope to send across more than ten infantry divisions with almost no heavy weapons in support. A force of this size would be slaughtered by Britain's defenders, which included many divisions of soldiers evacuated from France and equipped as infantry, enough armored forces to outnumber anything the Germans could bring across, tens of thousands of Home Guard militia, and several fully equipped divisions of reinforcements from Canada. In event of an invasion, the British government was fully prepared to use all means at its disposal to stop it, such as poison gas attacks and flooding the English Channel with burning oil. Poison gas could be used by the Germans as well, but they would need time to prepare countermeasures and to use their own gas. The British would gain a short-term advantage by being the ones to introduce gas, and a short-term advantage is all they would need to crush a fledgling invasion attempt.

Various schemes proposed to get around the outnumbered nature of potential German attackers have been proposed, but none would have been workable. Using paratroopers wouldn't work - even if the Germans had not lost most of their paratroopers in the invasion of Crete, and even if their slow, extremely vulnerable transports somehow got past the RAF, Britain was far too large and well-defended for Germany's paratrooper force to make any real difference. They excelled in attacks on pinpoint and isolated targets, such as Eban Emael and Crete, but jumping into a large area with many divisions of infantry and tens of thousands of militiamen, they would be slaughtered before they got a chance to do much of anything. For the Germans to use gas first would not work, because within a short period of time the military forces of both sides would use countermeasures. The main harm of countermeasures is that they slow an army down - of little harm to the British defenders, who can stay in their fortifications, but much more harmful to an invasion force attempting to seize beacheads and take territory. Having the Germans succeed at capturing more, or all, of the British forces evacuated from Dunkirk would also be insufficient. A little-known fact is that after being evacuated from Dunkirk (minus their equipment), most British soldiers were sent right back to France where they fought on until the final pullout. The British lost their heavy equipment at Dunkirk anyway, a fact which can hardly be made worse, and even without the evacuated men the British had more than enough infantrymen to fight off a German invasion. The Germans were physically incapable of shipping across an invasion force even half the size of the one they would need to have any chance of beginning a successful invasion.

Second, the supply situation. Once you have sent across an invasion force, it needs to be resupplied and reinforced before it is pushed back into the sea. An invasion force can't carry enough supplies on the landing craft to last more than a day or two, has few heavy weapons, and is almost certainly outnumbered by the forces the enemy can bring to bear given enough time. It needs extensive shipments of supplies , especially in the first few days, or it will run out and be annihlated. It needs heavy weapons and armor, or it will be crushed as soon as the enemy has enough time to bring the full force of his own heavy weapons to bear, or at best be unable to expand far from the initial beachead. It also needs large amounts of reinforcements, so that the main body of the army can be brought across and change the battle from a fight to gain and maintain a foothold, into an actual conquest.

Germany's ability to do this was, quite simply, very poor. Germany was never much of a seagoing merchant power, and as such it did not have very many freighters. Those it did have did not have the equipment or the space to be able to transport German tanks, a serious handicap. Much of the invasion's continued supply would rest on using the Rhine river barges... the same ones used to transport the initial landing, many of which would likely have been destroyed in that same landing, and which were at any rate both slow and vulnerable to attack and poor weather conditions (you can choose to invade on a pleasant day, but it's just tough if four days later, your supply fleet is decimated by high waves). The supply line of Sealion would be ridiculously inadequate, and would need to be many times larger to be physically capable of transporting enough supplies for a credible invasion. For Germany to build a substantial invasion fleet, or supply fleet, would require time (at least a year), would be very obvious to the rest of the world, and would divert resources from other programs. Germany was generally at the limits of what Hitler could realistically finance for the war at the time, so building more barges and freighters would mean less tanks, less airplanes, or less warships, any of which would hurt some other part of the war effort somewhere else.

The third factor is air superiority, easily the most famous of them all due to the Battle of Britain. Much too famous, since many people falsely assume that German victory in the Battle of Britain is all that would be necessary to permit a successful invasion. I hope that the rest of my essay demonstrates that it is not all that is necessary, but indeed, Germany does need to establish air superiority - preferably even total air supremacy - over the Channel and the invasion beaches for the invasion to work. The problem is that winning the Battle of Britain doesn't allow them to do this. Even if Britain was not consistently outproducing Germany in aircraft, and even if Britain did not have numerous advantages such as fighting on home turf (meaning that they could usually recover pilots who were shot down, while the Germans could not), and the use of Radar to give early warning of German attacks, that would not be good enough. Even if the British did not have the Spitfire fighter (which was not so important at that point in the war, when Hurricanes were much more numerous, shot down many more aicraft, and were considerably cheaper to build and maintain), even if the Germans had continued their program of bombing RAF airbases instead of turning to attack London (which would hurt the RAF more, but not be nearly enough to turn the tide), even if the British leadership had been different and decided to follow the much-inferior "Big Wing" policy of air defense, this wouldn't be enough.

The reason none of this would be enough is because of what the RAF planned to do if it lost the Battle of Britain. Quite simply, they would withdraw all surviving fighter groups to the north of Britain, out of range of German fighters, where they would be essentially invulnerable to attack. They would wait there until the Germans launched an invasion attempt, whereupon they would immediately fly south en masse to attack, denying the Germans air superiority. So due to this quirk of geography and German fighter range, there is basically no way for the Germans to get air superiority over the invasion (without, say, multiplying the size of their air force by many times - which would, again, require great advance planning and mean taking resources from some other part of the war effort), because the British would withdraw enough aircraft to safety to cause serious problems for an invasion. Something often overlooked about the Battle of Britain is that the British had multiple fighter groups, several of which were based to the north, out of range of attack. These were used as places where the pilots could rest, aircraft could be repaired, et cetera. They were at fairly high strength during the Battle, and thus even total annihlation of the aircraft actually in the fight would leave the RAF with plenty of aircraft in reserve for Sealion.

Withdrawing to the north would indeed leave the south of Britain vulnerable to bombing, but bombing was never decisive in the war even when the Allies launched thousand-bomber raids against poorly defended targets in 1944. In 1940 the Luftwaffe bombers, flying unopposed, would cause a good bit of damage and be very annoying, but they would not seriously impair Britain's ability to carry on the war, or to build up its defenses against German invasion. As such, if the bombing campaign continued unopposed before an invasion, it still would not be sufficient to weaken Britain's defenses (or, actually, prevent them from strengthening) to any great extent. Unopposed bombing would thus be of little to no help in preparing the way for a German invasion.

Last, but definitely not least, is the ability to protect the invasion fleet from naval attack. Something that is often sadly ignored in Sealion scenarios (except the ones that the Germans themselves came up with, one of the main reasons Sealion was never more than a pipe dream to them), is that the invasion fleet and its supplies must cross a body of water known as the English Channel. Water is the domain of the Royal Navy, at the time renowned as the most effective fighting force on the oceans. The forces of the Home Fleet, stationed at or near Britain at all times (usually at Scapa Flow naval base, out of range of German air attack), included at least one aircraft carrier, half a dozen to a dozen or so battleships and battlecruisers, and over a hundred smaller vessels such as destroyers, cruisers, and frigates. Dozens of the lighter vessels were stationed around the southern coast of Britain at any given time. In the event of an invasion, the ships already in the south would cause serious damage to an invasion fleet. Even if the invasion came as a complete surprise, within 24 hours the majority of the home fleet would be sitting in the middle of the English Channel, sinking everything that came within sight. They would certainly take losses, from various forms of attack, but this would not have stopped them. With their country about to be invaded, every last ship would be sacrificed if necessary to stop the invasion. It would not be necessary, however, because the Germans hadn't much to throw back at the battleship task forces in the way of its assault.

Most of the German navy was composed of U-boats. Great for commerce raiding, lousy for attacking well defended convoys, especially in 1940. Even lousier for attacking entire fleets of warships. Not to mention the fact that in the English Channel, in an area packed with destroyers and with very little room to manouver, using U-boats would be nothing short of suicide because they would have nowhere to hide. The German surface navy, at its height, never consisted of more than one battleship, a few battlecruisers and "pocket battleships", and ten to twenty lighter vessels. Thus, the Kreigsmarine at the height of its power was outnumbered between 5 to 1 and 10 to 1 by the Home Fleet. Not good odds if you have to not just fight a force of ships, but prevent them from so much as surviving for a day or two in the middle of the English Channel to sink your barges. At the time at which Sealion would have been likely to actually occur, the odds were even worse. The battleship Bismark was not yet finished, and the Germans had just successfully invaded Norway. This "success" left almost all of their fleet either destroyed, or having serious damage repaired. They had a few cruisers and destroyers to throw against the Royal Navy.

The German fleet may thus be entirely discounted from the question of how the Germans could prevent significant elements of the British fleet from sailing into the channel and sinking their invasion's supply line. The U-boats were useless in such a situation, and even if the surface fleet was not temporarily out of service due to Norway, it was not anywhere near large enough. Again we run into the old problem that if it is to be large enough, the building plan has to be started in advance (for capital ships, at least five years in advance!), and will take away substantial resources from the rest of the war effort. Battleships require a lot of steel to build. It doesn't work to postulate that the U-boats will starve Britain into surrender, either. First, it would be very hard to build more - they required precision manufacturing of many components, skilled workers to build them, and skilled officers to crew them. All of these were in quite short supply. Second, Britain is weakest in the later half of 1940, after that it becomes much stronger quite fast, and within a year is so well defended that there is no chance of a successful invasion. The problem is that this leaves only a year between the start of the war, and the time when Britain is supposed to be starved into being weak enough to allow an invasion. Not nearly enough time for a U-boat force of even twice the size and capability of the one the Germans had in 1940. The U-boat force was most effective later in the war, when it had more U-boats, better U-boats, and bases in France from which to easily reach the Atlantic. It must also be pointed out that building more U-boats detracts from the rest of the war effort, will likely lead to increased antisubmarine countermeasures by the British to compensate, and doesn't really help the problem of those battleships sitting in Scapa Flow deciding to sail down and sink the invasion's supply line.

Last but not least, aircraft - also not enough to stop the Royal Navy. The main problem is that they don't have the range to reach Scapa Flow, so they can't actually attack the British ships until they are already well on their way to where they will do the most harm. The Germans didn't have much capability to attack ships, anyway. They had no dedicated naval attack aircraft, no torpedo bombers, and their pilots lacked both training and experience in naval attacks. This was demonstrated in the Norway campaign, when they achieved a very low success rate against outnumbered, unarmed ships. In contrast, a battleship task force with a full screen of cruisers and destroyers has a tremendous number of antiaircraft batteries with all-around coverage, and can deal tremendous punishment to enemy aircraft. In the Pacific war, even when both sides had extensive antiship capabilities, air battles between American and Japanese fleets often lasted for many attacks over a period of days, with hundreds of aircraft being able to sink many major vessels in a task force, but virtually always leaving many survivors. Even a Royal Navy force with no air support at all could survive for the required few days in the channel under attack by an air force much better against ships than the Luftwaffe.

In fact, the Luftwaffe would have been quite bad against ships. Virtually all of its bombers were level bombers, which drop bombs from high altitude against stationary targets to good effect. Ships, however, can manouver so as to make themselves harder to hit - and level bombers thus become poor choices to use against ships even in the hands of expert pilots (only the Japanese had any real success with them in the war). Dive bombers and torpedo bombers are generally more effective. As mentioned previously, Germany had no torpedo bombers and its only dive bomber was the Stuka. The Stuka was the terror of the skies in the 30s, but by 1940 it was considered slow, vulnerable, and short ranged. Stukas would have suffered horrendous loss rates against the intense air defense of capital ship groups with concentrated destroyer screens. It's also worthy to note that, due to their range and speed, they could only make an absolute maximum of three attacks on Royal Navy elements sailing from Scapa Flow before they reached the channel. Realistically, only one or two. Thus the British fleet elements sailing south to stop the invasion would not experience significant air attack until they were already within range of the invasion fleet and its supply lines.

All these factors together should demonstrate that the Germans had no capability whatsoever to conduct a successful invasion of Britain. They lacked the ability to get a sufficient invasion force to Britain, to supply and reinforce it once it arrived, to protect its supply lines from the Royal Navy, and to establish protective air superiority over the invasion. For any Germany at all like the one we are familiar with, establishing air superiority during the invasion and protecting the supply lines from the Royal Navy are effectively impossible. The British can withdraw aircraft out of range of attack until the invasion, meaning that a huge increase in the Luftwaffe would need to occur to be able to establish air superiority despite these RAF reserves. Both a substantially increased German surface navy and a substantially increased Luftwaffe and Luftwaffe naval attack capability would be necessary to defend the invasion fleet against the Royal Navy. The problem with trying to remedy all of these is that they will need to be done at the expense of the army, leaving it much weaker for the invasion of France that has to happen before you can even get to Britain. Since Germany's aims lie on the continent - especially the primary war aim of Russia - Hitler cannot afford to focus on a strategy that favors amphibious invasions. And if he does, this must start well before the invasion is to occur, so that years in advance, it is plain to Britain that Hitler is persuing a strategy that can have no realistic use except in invading Britain.

http://gateway.alternatehistory.com/essays/Sealion.html
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Say i agree with everything you have just mentioned, why haven't you taken into account of the losses the British suffered during it's failed North Western European/Norwegian campaigns. Like the fact one of you senarios, if you deployed all those RN ships in the Channel and Dover Staits then there is virtually no freedom of movement, especially the Dover Staits is more or less a capital ship free zone also they would come under artillery bombardment from the ultra long and medium range artillery pieces also you mentioned U-Boats, the RN ships would have to retire to ports at night for protection, or the U-Boats could be use as hit and run, imagine over several nights four or five battleships are sunk and many others are damaged, yes this is proposterious but likely.

Then we have the Luftwaffe main failure, Goering, Goering forbade any follow up attacks on RAF airfields two days running. Also the Luftwaffe made no serious attempt to attack Radar, yes they attacked them early on in the piece but again Goering was not interested and fobbed off the British Radar as inconsequential, then we have another failure the Luftwaffe did not attack the RAF's lifeblood in aircraft manufacturing/repair plants, yes some were damaged but due in no small part to good luck but nothing else, and the Luftwaffe failed in attacking British industries/transportation hubs especially Ashford and Canterbury.

 

Another analysis,

Why Sealion is not an option for Hitler to win the war

One of the more common suggestions that crop up at all-too regular intervals goes along the lines of: "If Hitler hadn't switched from bombing airfields to bombing cities, then Operation Sealion would have worked."
Unfortunately for these suggestions, the plan for Sealion was perhaps the most flawed plan in the history of modern warfare. Getting it to a workable state requires so many changes that an author's artistic license would be revoked.
What follows is an analysis of Sealion in OTL.

• The background
• The plan
• The crossing
• Improvisations
• Resupply
• The obstacles
• The air
• The one exercise
• The July option
• The end

Operation Sealion - The Background

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When France collapsed, in mid-June 1940, the German staff had not even considered, never mind studied, the possibility of an invasion of Britain. Troops had received precisely zero training for seaborne and landing operations, and nothing had been done to gather the means of getting troops across the Channel.
At the time, the balance of naval forces in the region were as follows:


RNKriegsmarine5 capital ships1 capital ship11 cruisers1 cruiser53 destroyers10 destroyers23 destroyers on convoy duty20-30 submarines
In addition, the RN had countless smaller craft, including sloops, minesweepers, converted trawlers etc. These would have been of marginal value against warships. However, against the Rhine barges forming the main invasion transport force, they would have been effective.
Thus, any Sealion which takes as its Point of Departure the premise that German forces attempted to cross in the immediate aftermath of Dunkirk has to answer the following questions:

1. How are troops transported?
2. How will the Germans cope with contested air?
3. What is going to prevent the RN from interfering?
4. Once ashore, how will the German forces be resupplied?

If we turn our attention to point 3 for a while, the standard response is to say that the Luftwaffe could sink the RN ships. However, the Luftwaffe of the period had a pathetic record against warships. 39 RN destroyers took part in the Dunkirk evacuation. This operation required manoeuvring in a small harbour, with periods stationary while embarking troops. The Luftwaffe had command of the air for long periods. In these ideal conditions, the Luftwaffe managed to put out of commission a grand total of 4 destroyers. 4 out of 39 does not bode well for the Luftwaffe's chances.
However, the most typical AH suggests that if the Luftwaffe had continued to attack the airfields of 11 Fighter Group, Sealion would have worked.

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Operation Sealion - The Plan

We turn to the formal plan for Operation Sealion. The first instruction to begin planning was issued 2 July, giving 84 days before the invasion. (D-Day had been planned for 2 years). The Germans planned to lift 9 divisions (D-Day had 5).
In Normandy, the Allies had total naval and air superiority, a host of special equipment, considerable hard-won experience, and a considerable level of support and assistance from the local population. Despite facing defenders that can be most charitably described as second-line, the Allied forces did not have an easy time on D-Day.
Amphibious combined operations require close co-operation between the various branches. The Germans did not have this.
The Wehrmacht wanted a broad-front landing (it proposed Ramsgate to Portand - 275 miles). The Wehrmacht expected the Kriegsmarine to carry out a landing on this massive front in the face of an overwhelming superior navy, with no transport fleet yet assembled. The Wehrmacht document stated:

"The Luftwaffe will do the work of artillery, while the Kriegsmarine will do the work of engineers." ​

Meanwhile, the Kriegsmarine were displaying a similar level of understanding of the needs of the Wehrmacht. It stated that the time between first landing and the second wave of reinforcements and supplies would be 8-10 days. Thus 9 Wehrmacht divisions, without any heavy equipment or resupply, would be expected to hold out against the 28 divisions in Britain, which had unlimited access to supplies and the available equipment.
Hitler called a meeting on 31 July to decide among the various options. The Luftwaffe did not attend this meeting, although it was recognised that the Luftwaffe was essential to win air supremacy and to keep the RN out of the way. The Kriegsmarine proposed landing 10 infantry regiments at Folkestone, because a broad front would be impossible to protect. The Wehrmacht did not like this. The discussion moved on to purely army matters, so Raeder left the meeting. In Raeder's absence, Hitler announced that he favoured a broad front approach.
It was not made clear what the Luftwaffe was expected to do. On 1 August, Hitler told the Wehrmacht and the Kriegsmarine that an essential prerequisite was that the Luftwaffe gain "Total domination of the air." The Luftwaffe, however, was told by Hitler on the same day that it had to achieve "Temporary or local air superiority."
Examples of such total lack of co-operation abound.

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Operation Sealion - The Crossing

Ignoring for the time being the air battle, we will look at the mechanism proposed for getting 9 divisions across the Channel. This was the responsibility of the Kriegsmarine. The plan was:

• Block the west end of the Channel with U-Boats (operating in shallow, confined waters and required to stop, with 100% effectiveness, fast-moving warships rather than slow-moving merchantmen).
• Block the east end of the Channel with mines and 14 torpedo boats (with 20 enemy destroyers immediately to face).
• The main surface fleet of the Kriegsmarine was to "Break out into the Atlantic and draw the Home Fleet into following it."

Even if this exercise in wishful thinking worked perfectly, there was a problem. The RN had, based within the limits proposed, 3 light cruisers and 17 destroyers. However, the Kriegsmarine had thought of this, and decided that the barges would be adequately protected if the soldiers on the barges (travelling at night) "Fired at unidentified ships".
Less adequately considered by the Kriegsmarine was how to capture an intact port. The chosen port was Dover. The operational plan was to sail the barges in and capture it. This was the detailed plan. The defences of Dover included a considerable amount of equipment "Surplus to establishment" (courtesy of HMS Sabre, which had passed on abandoned equipment from Dunkirk). This equipment included:

• 3 Boys anti-tank rifles
• 19 Bren guns
• 4 mortars
• 3 21" torpedo tubes
• 8 6" guns
• 2 12 pounder guns
• 2 14" guns, called Winnie and Pooh.

There were two limiting factors. Firstly, lack of ammunition (the anti-tank rifles had only 19 rounds each) and lack of personnel. (The CO complained to his diary that he didn't have enough troops to use all the weapons he had, and he couldn't request more troops because he shouldn't have all this equipment in the first place.)
Overall, the plan to capture Dover was far less well thought out than the Dieppe fiasco.
The German logistical plan to get troops and supplies across the Channel were not as professional and thorough as that for the initial crossing described above.
To get the first wave across, the Germans gathered barges and tugs, totally disrupting their trade in the Baltic. Eventually, 170 cargo ships, 1277 barges, and 471 tugs were gathered. These were, inevitably, bombed by the RAF (about 10% being sunk before they dispersed again). The barges were mainly those designed for use on the Rhine, with a shallow freeboard. They sink in anything above Sea State 2. The wash from a fast-moving destroyer would swamp and sink the barge. (Correct: the RN could sink the lot without firing a shot).
The situation with regard to mariners for the barges with experience of the sea was even worse. When used as a landing craft, the barges, tugs and motorboats required extra crew. In total, the Kriegsmarine estimated that a minimum of 20,000 extra crew would be needed. That's 20,000 extra crew at least knowledgable of matters maritime. By stripping its ships to the minimum (which doesn't bode well for the Kriegsmarine if it is required to fight a fleet action), the Kriegsmarine was able to supply 4,000 men. The Wehrmacht and Luftwaffe transferred 3,000 men who had been sailors in civilian life, and an in-depth trawl of the reserves and the factories and the drafts brought forward another 9,000 men. After digging through the entire manpower cupboard, the barges were still 4,000 men short of the minimum required.
Nothing could alter this, and the Kriegsmarine came to the reluctant conclusion that the barges would have to sail in an undermanned condition.
Finally, the barges were under-powered for open water operations, and required towing. The basic unit was a tug towing two barges, and travelling at 2-3 knots, in the Channel, which has tides of 5 knots. Given that the distance that the far left of the invasion had to cross, a minimum of 85 miles, the poor bloody soldiers would be wallowing for a minimum of 30 hours in an open boat, and expected to carry out an opposed amphibious landing at the end of it.
The most comical element of the plan, however, was that for manoeuvring the flotilla. The plan was that this huge mass of towed barges would proceed in column until reaching a point ten miles from the landing beach, then wheel and steer parallel to the coast. When this was complete, the vessels would make a 90 degree turn at the same time, and advance in line towards the coast. This was to be carried out at night, and controlled and co-ordinated by loud hailers. There had been no chance to practise the operation, and there was less than one skilled sailor per vessel.
If this seems to be a nightmare scenario, and a recipe for disaster, it is as nothing compared to other elements.

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Operation Sealion - Improvisations

Given the shortage of transports, it was inevitable that the Germans would look to improvisations. These proved to be decidedly imperfect.
The Engineer Battalion 47 of VII Army Corps was designated as having responsibility for the "construction of seaworthy ferries out of auxiliary equipment, local supply and bridging equipment". What was unusual in this was that this task, requiring a good knowledge of matters maritime, was tasked to this particular battalion, which had its home base in Bavaria.
The engineers were nothing if not enthusiastic. They built rafts from pontoons, and were undismayed when half of these rafts sank while in harbour. Attempts to provide these rafts with power failed, because they broke up under the strain. Nonetheless, the Wehrmacht announced that these rafts would be towed behind the barges being towed by the tugs, and that the horses would thus be transported across the Channel on these rafts, saving the difficulties of loading the horses into the barges. One wonders what the horses would have made of this concept.
The engineers turned their attention to pontoons used for crossing rivers. Even the most optimistic observer had to regard this as a failure. The open pontoons filled with water and sank. The iron beams holding the pontoons together snapped in waves, and the exercise was discontinued.

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Operation Sealion - Resupply

The next phase of this analysis is resupply of those troops that make it ashore.
It was recognised that it was essential to capture an intact port. Dover was the port chosen. The Kriegsmarine were told to put the Wehrmacht ashore in Dover, but nothing in the Wehrmacht plans indicates that they were required to capture Dover.
It was planned to drop all the paratroopers on the heights north of Dover to help 16 Army. However, 9 Army had been told that all the paratroopers would be dropped near Portsmouth. The Luftwaffe had been told to support the seaborne landings, but no escort was intended for the paratroop drop, wherever it might end up taking place.
In a stroke of tactical genius, the Dover drop zone was about the worst possible for human ingenuity to select. It was intended to drop the paratroopers 10-15 miles from the target (shades of Arnhem) in a landing zone that was a mixture of hills and hop fields. No resupply was planned.
As for beachheads, there was literally no plan for tactical development. The plan states:

"Once local beachheads have been won, junior commanders will set about co-ordinating small units in their vicinity and use them to seize objectives on their front. Weak but continuous fronts will be formed. These will be extended and deepened by a continuous flow of reinforcements. After daylight, but not before, the Luftwaffe will support the main effort of the assault troops, acting as artillery." ​

It goes on later:

"Premature crossing by higher staff will be valueless, as it would interfere with the flow of reinforcements. It will be the duty of regimental and battalion commanders to direct operations. The restricted area of the bridgehead will not be able to accommodate vehicles, supply columns and staffs." ​

The Kriegsmarine's responsibility for supply ended with dumping the stuff on the bridgehead. The Wehrmacht had given the responsibility of ensuring that supplies were moved from the beach to the front to, well, to whoever happened to be on the spot and felt like getting involved in this operation.
Can you say chaos?

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Operation Sealion - The Obstacles

Just to make matters worse, no engineers were included in the first wave, and no equipment to deal with obstacles.
The bulk of 9 Army was to be landed on the Romney Marshes, and would have to first of all deal with the Martello Towers - which against modern artillery, would be useless, but the Germans had no modern artillery with them. They would have to be dealt with by rifles and grenades.
Then 9 Army has to cross the Royal Military Canal. Now again, this is an antiquated defence, but would actually prove to be a problem. It is 60 feet wide - and the Germans have brought no means of getting across it. Within 30 minutes of the Romney Marshes, the British had no less than 100 pieces of artillery.
In the immediate vicinity of 9 Army, the British had the following:

• 2 Territorial Divisions
• 1 Brigade from India
• 1 Brigade from new Zealand
• 1 Armoured Division
• 1 Canadian Division
• 1 Army Tank Brigade

Then there is the example of the question of life jackets. Thousands of life jackets had been provided. However, despite all the best efforts of the planners, there were only sufficient for the first wave. The intention was, according to the plan, that these life jackets would be brought back again by the boats for the second wave. The problem was that these life jackets were worn beneath the combat pack. Those involved would be expected, on landing on an open beach while under fire, to first take off their pack, then their life jacket, and then don combat pack, and only then start doing something about those inconsiderate British soldiers shooting at them. One wonders what the veterans of Omaha beach would say about the viability of this.
Not that it would have been of the slightest use. While the Wehrmacht had been given strict instructions to do this, no-one had been made responsible for collecting the life jackets and return them to the boats. The boats, however, did have strict instructions not to wait once they had unloaded their troops. The life jackets would have piled up uselessly on the beach.
Then there was the matter of artificial fog. A serious conflict of opinion arose between the Wehrmacht and the Kriegsmarine regarding the use of artificial fog. The Wehrmacht wanted it, for the quite reasonable reason that it would be the only form of protection available on the open beaches. The Kriegsmarine was opposed to its use for the also quite reasonable reason that the landings were quite difficult enough without making it impossible to see anything.
Inevitably, a compromise solution was found; it was ruled that the Wehrmacht would get to decide whether or not to deploy artificial fog, but that it was the responsibility of the Kriegsmarine to actually deploy it, if practicable. This compromise would have very quickly resulted in the pantomime discussion of "Oh yes it is!" "Oh no it isn't!".
Still, the Germans would have had one thing in plentiful supply. In a decision that is difficult to understand, given that there was no heavy equipment for them to pull, the Germans decided to include over 4,000 horses in the first wave.

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Operation Sealion - The Air

So far, we have looked at an exercise in wishful thinking. We now turn to the Luftwaffe in order to gain an appreciation of the inability to count.
The strength of the Luftwaffe at the point of Sealion was about 750 bombers and 600 Me109 fighters. The Germans estimated the strength of Fighter Command at 300 planes, of which 100 were not available to the RAF.
In fact, 11 Fighter Group had 672 planes, of which 570 were Spitfires and Hurricanes.
The Luftwaffe, with its resources, was expected to do all of the following:

• Act as artillery for the landing forces
• Keep the RN out of the Channel
• Win total air superiority
• Prevent British Army reinforcements from getting to the zone by bombing railway lines
• Make a mass attack on London to force the population to flee the city and choke the surrounding roads.

One presumes that, in their copious free time, the Luftwaffe pilots would eat three Shredded Wheat for breakfast.
Now, we actually have a pretty fair idea of how the RAF would have reacted if the southern airfields had been made untenable. Dowding had made preparations to pull 11 Fighter Group back to the Midlands in order to preserve an effective fighter opposition to an invasion proper.
This would have placed the RAF fighters out of the range of the German fighters. Given the disasters that the Luftwaffe bombers suffered when they undertook unescorted daylight missions, we can see that while Kent and Sussex could have had a lot of bombs dropped on them, the industrial heartlands and the RAF and the RN ports and the British Army concentrations would have been pretty much untouched.
So what happens if the Luftwaffe go after the airfields more effectively? 11 Group pulls back to the Midlands. The Luftwaffe pounds Kent and Sussex for a while, achieving diminishing returns (although the hop fields, and hence the output of beer, will be reduced noticeably).
When Sealion starts, 11 Group has had chance to rest and recover and build up its strength, while the Luftwaffe have had to carry out a lot of sorties. On Sealion, 11 Group, in addition to 10 and 12 Group can re-enter the fray. They won't have so long over the area of operations, but against that, they have a huge number of potential targets - barges and landing beaches and transport aircraft. The Luftwaffe fighters have equally limited time over target, and they have a huge number of things they have to protect. If any target is damaged severely, Sealion is made unworkable. Thus the RAF need to succeed only once, while the Luftwaffe need to succeed everywhere and every time.
Meanwhile, RAF's bomber command has just been presented with a massive, unmissable target in the form of the barge fleet. If the Germans are flying fighter cover over the barges, then these fighters are not flying as escort for the German bombers. If they are not escorting the bombers, then the bombers are unprotected against RAF fighters. In this case, the Luftwaffe will be ineffective at keeping the RN Home Fleet at bay. In essence, if the RAF doesn't get the barges, then the RN does.
It is worth reiterating the key figures, that of fighters. At the time in question, the fighters available were 600 for the Luftwaffe, and 670 for the RAF.
Britain was outproducing Germany in planes, so the proportions are steadily moving in Britain's favour.
Another key element was the number of trained pilots. Again, Britain has a massive tactical advantage. A British pilot who survived being shot down could quickly be returned to operational status. A German pilot who survived being shot down became a prisoner of war, and removed from the battle.

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Operation Sealion - The One Exercise

One single main exercise was carried out, just off Boulogne. Fifty vessels were used, and to enable the observers to actually observe, the exercise was carried out in broad daylight. (The real thing was due to take place at night/dawn, remember).
The vessels marshalled about a mile out to sea, and cruised parallel to the coast. The aramada turned towards the coast (one barge capsizing, and another losing its tow) and approached and landed. The barges opened, and soldiers swarmed ashore.
However, it was noted that the masters of the boats let the intervals between the vessels become wider and wider, because they were scared of collisions. Half the barges failed to get their troops ashore within an hour of the first troops, and over 10% failed to reach the shore at all.
The troops in the barges managed to impede the sailors in a remarkable manner - in one case, a barge overturned because the troops rushed to one side when another barge "came too close".
Several barges grounded broadside on, preventing the ramp from being lowered.
In this exercise, carried out in good visibility, with no enemy, in good weather, after travelling only a short distance, with no navigation hazards or beach defences, less than half the troops were got ashore where they could have done what they were supposed to do.
The exercise was officially judged to have been a "great success".

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Operation Sealion - The July Option

Some have suggested that an immediate invasion in July would have produced success. This claim derives, ultimately, from Guderian's claim that it would have been easy at this time. This, of course, is the same Guderian who claimed to have been the first German to reach the Atlantic coast during the Battle of France. This claim was made on reaching Noyettes, on the Channel coast.
It is perfectly true that the British Army was less able to resist in July than it was by September. That, however, misses the point in a fairly dramatic fashion. The difficulty facing the Germans was not beating the British Army, but it was getting across the Channel in the face of the RN and the RAF.
The German capacity for doing this is lower in July, and the odds are more heavily stacked against them.

• Firstly, the Kriegsmarine is weaker, as a result of unrepaired battle damage from the Norway campaign.
• Secondly, the German forces haven't had chance to gather transports. Without the efforts of bringing up the Rhine barges and scavenging and scrounging to the extent that took place, the Germans have the capacity to lift less than one infantry division.
• Thirdly, according to the precise timing, the Germans are either turning their backs on the French army before the Armistice with France, and allowing the French army to recover and reorganise; or the Germans beat France and immediately turn towards Britain, without taking time to rest their pilots and Panzer crews, and without taking time to repair battle damage to their planes and tanks.
• Fourthly, the Luftwaffe is not being allowed any time to inflict attrition on the RAF. Much to the disgust of the French, Britain had retained 24 fighter squadrons as Home Reserve. These squadrons were rested, maintained and ready. The Luftwaffe, on the other hand, have been flying a lot of sorties. The British Radar chain is undamaged, as is the command and control; in short, one is re-running the Battle of Britain, but giving the Luftwaffe tired crews and machines in need of repair, giving the RAF peak efficiency, while ensuring that the Luftwaffe have even more essential tasks to carry out than in a September Sealion.

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Operation Sealion - The End

We can choose to wave a magic wand, and wipe out the RN and the RAF, and examine how successful the invasion was likely to be in their absence. Sandhurst has done this on four occasions to my knowledge. Both sides were given the historical starting positions, with an invasion date of 24 September.
In each case, the details of the fighting varied, but by each analysis resulted in 27 September dawning with the Wehrmacht holding two isolated beachheads, one at roughly 2 divisions strength on Romney March, and one of 1 division at Pevensey. Each were opposed by more numerous forces, with growing numbers of tanks and artillery. German resupply was still across open beaches.
Operation Sealion can only be described as a blueprint for a German disaster.

 

Something I hadn't seen before. an interesting read.

Operation Sea Lion: A Joint Critical Analysis
Military history contains many lessons from which the warfighting doctrine of the individual services, as well as joint doctrine, is derived. World War II stands as one of the major contributors of valuable lessons learned. From a joint and combined warfighting perspective, Germany's planning and preparatory military actions to the invasion of Great Britain after the fall of France are instructive. Their plan, called Operation SEA LION by the Germans, was never carried out, as certain prerequisite conditions were never achieved, and Hitler elected to move on to other operations. But Germany could have been successful in invading and, if necessary, occupying Great Britain had they exercised joint and combined operations to achieve better unity of effort within the German military, remained focused on key British operational centers of gravity, and exploited the capabilities of friendly nations such as Spain, Italy, and the Vichy government of France.

http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA421637&Location=U2&doc=GetTRDoc.pdf

 

thanks for all the info! what it boils down to which I have stated before is that Hitler believed England wouldn't be a threat to the Reich.

 

I read that paper listed above by JCF. So, that tripe is what passes for good work at command and staff colleges in the US military today?!! God help the US military.

 

LOL yeah. Over all the years and that is about the only thing that says it was possible LOL.

 

It's sad to see so much ink being wasted about a subject that may have been possible, but highly improbable on so many strategic levels. Hitler once said, during a military briefing that the Battle of France had cost him tens of thousands of casualties over the course of nine months and that it greatly troubled him that that many casualties could be inflicted upon the German Military in the course of a single night by the Royal Navy.