Sealion compared to historical amphib assaults?

[Tsofian]

On the other hand, the Germans had more guns, including a couple of powerful 88 mm Pak guns, pointing along the beach itself, which the British had not.

One of these days I'll work it out more precisely.

The Germans needed fairly decent anti tank weapons to defeat the M4 Shermans and Churchills the allied would field. The Panzer III and IV of September of 1940 were very weakly armored with as little as 20mm side armor. Even HE from any field gun would penetrate this. The US had sent 75mm guns with lots of ammunition and these were being used as beach defenses guns. These would have served very well both shooting up barges and hitting tanks.

The effectiveness of 75mm guns in beach defense was clearly indicated during the assault on Corregidor in May of 1942. The Philippine scouts with a pair of 75mm guns and a pair of 37mm infantry weapons did massive destruction on the Japanese troops landing in front of them. The beach conditions on Corregidor are in some ways similar to the south coast of England, although probably better for tanks than the English shingle.

There are a lot of well armed troops on the English shore. They are fairly well armed and are highly motivated. They have no illusions about what defeat means for their country, themselves and their families. The Germans had a healthy respect for British troops on the defensive.

[sitalkes]

This file compares the landings made in Europe in WW2 with Sealion: https://drive.google.com/open?id=1R6_cs ... 37duY4uzVQ

[sitalkes]

1. What sort of Sealion are you referring to? There seem to be a lot of assumptions being made. Principally, when do you see the invasion happening and what is the result of the Battle of Britain?
2. Factors to compere:
a. attackers
i. naval fire support,
ii. aerial fire support,
iii. Artillery support
iv. rate of cross beach movement,
v. Air superiority yes/no
vi. Naval superiority yes/no
vii. Special equipment
viii. Planning time density,
ix. Doctrine
x. Training
xi. Organisation
xii. Experience
xiii. Motivation/troop quality
xiv. Numbers
xv. density
xvi. Equipment
xvii. Surprise – strategic/tactical, yes/no
xviii. Diversions
xix. Availability of supplies and replacements and how quickly they can land
xx. Length of supply lines
b. defenders,
i. aerial fire support,
ii. Artillery support
iii. fortifications,
iv. Air superiority yes/no local or air supremacy?
v. Naval superiority yes/no
vi. Special equipment
vii. Planning time,
viii. Doctrine
ix. Training
x. Organisation
xi. Experience
xii. Numbers
xiii. Motivation/troop quality
xiv. Density
xv. Equipment
xvi. Availability of reinforcements and travel time to beaches; Strategic concerns likely to draw them away or delay them
xvii. Availability of supplies and replacements and how quickly they can arrive
xviii. Distance to supply base and their capital/ultimate objective of invasion
c. Other factors
i. terrain, offshore obstacles (shoals etc)
ii. weather, tides, currents, number of hours of daylight.
iii. Length of landing area
3. Dieppe was a success on the beaches on the flanks of the ports. This is what the Germans planned to do, attack the beaches frontally not the ports.
4. The British fortifications, such as they were, were tested as being immune to rifle calibre ammunition. but were penetrated by 20mm shells. The Germans had lots of 20mm and 37mm guns - for which I imagine fire control etc is not so important due to their high rate of fire. Included in the first wave were over 300 armoured vehicles plus artillery, and anti-aircraft guns. The second wave included many more and, for the first time, a regiment (72 launchers) of nebelwerfers. The Germans made 30 auxiliary gunboat conversions, armed with warship and AA guns, to provide fire support on the beaches. Most barges had a 75mm field gun mounted at the front and/or an AA gun mounted at the rear. There were also 185 escorts and 47 Siebel/Herbert ferries with similar or heavier armament plus hundreds of smaller boats armed with machine guns. On Omaha beach it was destroyers coming very close to the beach that provided the most effective gunfire support, not the battleships and cruisers, so it is likely that the sort of naval gunfire support available would have had some effect.
5. The Germans had their act together when it came to operating in a combined arms situation and that included the use of radios, for which they did a lot more training and were better equipped than the British. The commander of invasion convoy ‘D’ had what was possibly the world’s first purpose built HQ ship, the tender Hela. The commander of convoy C shared his ship with the commander of VII Corps, whose troops he was carrying.
6.
2700 tons a day were needed for the 9 divisions in the first wave (including the equivalent of a panzer division making up the difference of six Fallschirmjäger, Jäger, and Mountain divisions which were smaller than normal divisions, with one missing a regiment). The Fallschirmjäger division and an air landed division were to arrive by air and would probably be mostly supplied by air. If air superiority was available then other troops could be air-supplied to some extent, too. They also sourced a lot of their supplies locally and were to bring two weeks’ rations with them in the first wave . There were about 26 miles of beaches suitable for landings in the invasion area. Bad weather only occurred on five days between September 19 and October 20 1940, so the beaches would have been viable supply sources. According to British calculations, a total of 10,400- 13,600 tons could be landed daily over that length of beaches using barges. The beach estimate is based on having four barges per mile and each barge unloading 100 tons per day (each barge could carry 600 tons).

The British troops were no better motivated than all the other troops defending their homelands that had been defeated by the Germans. Even the Ost troops defending Omaha beach fought because an NCO had a gun at their back, until they ran out of ammunition. What is more important is their training, organisation, equipment, doctrine, experience, and leadership, all of which were inferior to that of the Germans. The Germans also planned for their plan to be disrupted in the heat of battle and trained their troops that way, whereas the British did not.

[Gooner1]

The British troops were no better motivated than all the other troops defending their homelands that had been defeated by the Germans. Even the Ost troops defending Omaha beach fought because an NCO had a gun at their back, until they ran out of ammunition. What is more important is their training, organisation, equipment, doctrine, experience, and leadership, all of which were inferior to that of the Germans.

The Germans never broke the front of the BEF in France and Flanders.

The German IV Corps opinion:
"The English soldier was in excellent physical condition. He bore his own wounds with stoical calm. The losses of his own troops he discussed with complete equanimity. He did not complain of hardships. In battle he was tough and dogged. His conviction that England would conquer in the end was unshakeable.
The English solider has always shown himself to be a fighter of high value. Certainly the Territorial divisions are inferior to the Regular troops in training, but where morale is concerned they are their equal.
In defence the Englishman took any punishment that came his way. During the fighting IV Corps took relatively fewer English prisoners than in engagements with the French or the Belgians. On the other hand, casualties on both sides were high.

The Germans also planned for their plan to be disrupted in the heat of battle and trained their troops that way, whereas the British did not.

The defending troops plan was simple - Fight until the last man and the last round.

[Gooner1]

The Royal Navy was reluctant to commit major units to the channel in daylight. The conventional wisdom is that Op Sealion might have been mounted but the landed force was unsustainable in the face of an undefeated RAF and RN.

What do you consider a major unit? HMS Revenge was stationed in Plymouth. Which 'conventional wisdom'? A dispassionate examination could easily conclude that the German invasion fleet would be unlikely to get more than a few miles out of port before being set upon by the Royal Navy.

No one knows whether the Home forces would have fought better than Freyburg's men.

Freyberg's men - apart from being short of their heavy weapons, comms equipment, tools and stores - had just been evacuated from Greece, with the knowledge that Crete was a stepping stone to their evacuation back to the Middle East. They lacked the 'garrison mentality'.

[Sheldrake]

The Royal Navy was reluctant to commit major units to the channel in daylight. The conventional wisdom is that Op Sealion might have been mounted but the landed force was unsustainable in the face of an undefeated RAF and RN.

(1) What do you consider a major unit? HMS Revenge was stationed in Plymouth. Which 'conventional wisdom'? A dispassionate examination could easily conclude that the German invasion fleet would be unlikely to get more than a few miles out of port before being set upon by the Royal Navy.

No one knows whether the Home forces would have fought better than Freyburg's men.

(2) Freyberg's men - apart from being short of their heavy weapons, comms equipment, tools and stores - had just been evacuated from Greece, with the knowledge that Crete was a stepping stone to their evacuation back to the Middle East. They lacked the 'garrison mentality'.

Re 1: The Germans managed to get all the way up the channel in Feb 1942 despite all sorts of precautions.

Re 2. That reads as a bit of a slur on the fighting spirit of the Australian, British New Zealand and Greek troops. Crete was a hard fought campaign , as can be testified by the losses, medals awarded and casualties inflicted. The local civilian population putting up as tough a fight as might have been expected of the Home Guard.

It would be arrogant to assume that anything is a certainty. There is no certainty that the British would have fought harder on British soil than on any corner of a foreign land or harder than Frenchmen Poles or Russians for theirs.

[Gooner1]

Re 1: The Germans managed to get all the way up the channel in Feb 1942 despite all sorts of precautions.

Re 2. That reads as a bit of a slur on the fighting spirit of the Australian, British New Zealand and Greek troops. Crete was a hard fought campaign , as can be testified by the losses, medals awarded and casualties inflicted. The local civilian population putting up as tough a fight as might have been expected of the Home Guard.

It would be arrogant to assume that anything is a certainty. There is no certainty that the British would have fought harder on British soil than on any corner of a foreign land or harder than Frenchmen Poles or Russians for theirs.

1. Warships moving fast in poor weather, compared with large numbers of slow invasion craft leaving ports days before the invasion.

2. Two of the German landings on Crete failed. The landing at Maleme succeeded because of the withdrawal of a NZ infantry battalion.

3. The BEF had already proven the British could fight better than the Poles, the French and the Russians whilst on foreign soil. The idea that the British would then fight worse whilst on home soil is somewhat bizarre.

[Gooner1]

Most people would assume that Omaha beach was much more strongly defended, which may be true in terms of concrete, mines and other obstacles, but I do think the British defences by the end of September 1940 (the earliest possible date for an invasion) were stronger in terms of men and firepower per km. Of course, a direct comparison is difficult because the defences were organized and equipped very differently. The Britsh had about ten coastal defence guns of 5.5in and 6in calibre pointing out to sea, the Germans had none. On the other hand, the Germans had more guns, including a couple of powerful 88 mm Pak guns, pointing along the beach itself, which the British had not. Concerning indirect artillery support, the British had more and bigger guns within range, including four 9.2in (234 mm) railway guns.
It seems a safe assumption that the Germans, even if they somehow managed to get across in good order and on schedule, would have suffered at least as many casualties on S-Day as the Americans did on D-Day.

Given the strength of the British artillery it seems highly likely that the Germans would have suffered severe losses before even getting to the beaches.

[sitalkes]

[The Germans never broke the front of the BEF in France and Flanders.

Which is why they were in full rout and panic by the time they got to the Dunkirk perimeter, though it did take them only a day or so to reorganise and recover (May 24, 1940: the day Britain won the war). and of course no British troops were defeated in Norway or North Africa, either.

The defending troops plan was simple - Fight until the last man and the last round.

No it wasn't, the plan required a retreat to a defended line followed by an armoured counter-attack. The battle would have been won or lost at sea and in the air anyway.

All the above posts neglect the combined effects of cross-channel guns, mines, U-boats, S-boats, and Luftwaffe attacks. The combined effect would have been greater than the one of them alone. There was the equivalent of a battleship's guns sitting on the other side of the channel, including radar guided 16" guns, and their effect on a slow Revenge class battleship that was also trying to dodge air attacks, mines, shoals, and U-boats in a narrow sea space is not to be discounted (especially if air superiority had been gained and the spotter aircraft could operate). The channel guns would also have provided some naval gunfire support for the landings and most of the 100 guns available would have been able to support the fleet as it crossed for at least half the crossing.

[sitalkes]

2. Two of the German landings on Crete failed. The landing at Maleme succeeded because of the withdrawal of a NZ infantry battalion.

For the first time the whole German airborne division was to drop together for Sealion; they refused plans to drop them at various places on the south coast. Instead they were to drop fairly close together. This was an alternative plan for Crete but instead the troops were spread out and the British knew precisely when and where they were going to land (though they didn't tell the lower commands all the details). If they had dropped together at Maleme they might have been more successful.

Most of the British anti-tank guns were withdrawn from beach defences to the GHQ line, so the anti-tank fire on the beaches would have been from field guns and anti-tank rifles. The emergency coastal batteries were sited to fire out to sea and often could not depress enough to cover the beaches. The American 75mm guns were mostly issued to artillery units and not mounted as coast defence guns. The density was pretty low at 2 division equivalents to cover the entire landing area.

[Tsofian]

What is more important is their training, organisation, equipment, doctrine, experience, and leadership, all of which were inferior to that of the Germans.

I snipped all sorts of interesting stuff, but I really want to concentrate on this statement. In general this may be true but for Sealion it is demonstrable less so.

Training
The Germans were extremely poorly trained for an amphibious assault of this scale. Many troops had only the most meager training at such basics as getting off the boats, let alone transferring from transports to assault craft in a seaway. For the most part the Allies practiced and drilled on these tasks for considerable periods prior to an invasion. I wonder how many German soldiers had actually been at sea in their actual assault craft, or transport vessel in a training exercise? I don't think any exercise bigger than a battalion had been conducted, and even those were rare.
Had any of the vessels worked together? Had any of the M35 Minesweepers done any NGFS practice? Any of the converted gunboats? Any of the armed barges?
Doctrine
In terms of doctrine the existing doctrine for the Germans either not applicable or non-existent. Their doctrine ends when the troops fall in on the embarkation docks and doesn’t beginning again until the troops are off the beach and can begin using their standard tactics again. The British have a standard defensive doctrine that should be very effective in the campaign.
Experience
The German troops, except for those who might have been in Norway have no experience either. Yes they are combat veterans but none have been part of an over the beach assault. For the British even the old soldiers from WW1 have experience in holding defensive lines.
Leadership
Even though you mention that there were command ships in the invasion force and a radio network I can find nothing like the joint command in an Allied operation. The KM leadership wanted nothing to do with the operation from the off and the Luftwaffe thought they could do it alone. There was almost no “joint” in Sealion. The British under Admiral Ramsey had pulled off an impromptu joint operation of immense scope and done it under the worst possible circumstances. They would screw up joint operations in the future but they had a staff and a process that occasionally worked.
Equipment
Almost everything in the invasion fleet itself is cobbled together. The barges are hastily converted. The very small number of gunboats are also. The tanks of the initial wave are floating Panzer IIs or submersible MKIII and MK IV as well as a number of conventional tanks that will land over the beach. This generation of Panzers had weak armor and poor armament (although some Panzer III with the 50mm gun upgrade would be included. Yes some of the pill boxes would have been vulnerable to 20mm and 37mm but many others would not have been as they were built to a higher standard of protection. In any case the weapons were equal to the task even if they were not the bestest newest coolest. They were the good enoughest. Vickers, Lewis, Bren and other machine guns were plenty good enough to cause carnage on the beaches.
I am not at all sure that the Germans have any real advantage in these areas

[Tsofian]

All the above posts neglect the combined effects of cross-channel guns, mines, U-boats, S-boats, and Luftwaffe attacks. The combined effect would have been greater than the one of them alone. There was the equivalent of a battleship's guns sitting on the other side of the channel, including radar guided 16" guns, and their effect on a slow Revenge class battleship that was also trying to dodge air attacks, mines, shoals, and U-boats in a narrow sea space is not to be discounted (especially if air superiority had been gained and the spotter aircraft could operate). The channel guns would also have provided some naval gunfire support for the landings and most of the 100 guns available would have been able to support the fleet as it crossed for at least half the crossing.

The Germans guns didn't have radar fire direction in 1940 (If you can site a source that indicates they had radar blindfire ability in September 1940 I would be very interested-it would require the radar to be able to spot the splashes of the shells and target ships.), plus the fact the German coastal guns in the Channel had a hit rate less than .1% for their shooting over the entire war just indicates that these aren't going to play much of a role. The Luftwaffe has almost no maritime strike ability, especially at night. They have a very limited number of torpedoes and heavy AP bombs which are the only weapons that will effect capital ships.

The other three items work both ways, both sides laid hundreds of mines. The ability of the Germans to lay the fields they wanted to with the available resources has been questioned on this forum several times. I'll let you go back and look through those threads. One thing from that stands out though is the requirement for the M-35 minesweepers and the R boats and S boats to provide escorts for the mine laying and mine sweeping operations. For the German minefields to have the desired effect they have to risk resources that are allocated to several missions in the invasion. The same can be said for German efforts to breach the British fields. The British planned on putting their small submarines in the channel and they also had MTBs. By the time the invasion started how many of the German ships are still operation, even before the invasion convoys load up?

[Carl Schwamberger]

Tarawa is also an interesting comparison. The problems of communications from shore to ships might be similar. At Tarawa US commanders were able to reroute assault groups away from some beaches that were too hot and to places where they might be more effective, or to hold up the waves if the needed to. I do not see how the Germans could have done this with the communications equipment and network they appear to have had available.

Part of the communications problem at Betio island in the Tarawa atoll was the division forward CP group took much longer than anticipated to get ashore, then the Assistant Division commander did not follow the plan once ashore. The forward CP was out of action for half of the three days of the battle. The robust nature of the communications network as whole saved the situation. The regimental commanders had enough radio equipment to link to each other as well as their battalions & the flexibility to coordinate with each other without the CP ashore.

The failure of a experienced & well trained formation to establish a key CP on schedule shows how seriously things can go wrong, and how training & experience is required to solve such problems.

Any takes on if the supply for twenty divisions, or even ten could actually be sustained by the German sea lift at hand? What about after losses in barges and ships?

No way the Germans could have gotten 10 divisions across, let alone landed and supplied. Just landing a division's worth of troops at select ports in (then) neutral Norway required nearly every warship in the Kreigsmarine's inventory. With fewer assets and an already alert Britain the possibility of repeating that limited operation would have been beyond German capabilities.

Exactly. Missing from these debates is a decent analysis of the actual transport on hand. Was there enough to sustain to ammunition supply during the next couple weeks? Or fuel & horse fodder? Its silly to think that several thousand tons of horse feed & vehicle fuel can be captured and redistributed on any practical scale.

[Sheldrake]

snip

3. The BEF had already proven the British could fight better than the Poles, the French and the Russians whilst on foreign soil. The idea that the British would then fight worse whilst on home soil is somewhat bizarre.

There is a British smug complacency about the performance of the BEF in 1940.

For a start the BEF faced the German feint into Belgium rather than the main armoured force, so claims that the Germans never broke through are meaningless. When the BEF did have to fight it it did not do particularly well,except in dogged static defence.

Much of the BEF was ill trained for mechanised warfare. Wireless sets were in short supply and training curtailed for fear of compromising security. Few units or formations were able to communicate by wireless or practiced in long moves (Montgomery's 3 div the exception) The Arras counter attack was a shambolic affair , marked by a lack of co-operation between arms and the loss of most of the attacking armour. Yes I know, that even as a tactical failure it disproportionately worried some Germans. But it was an example of how not to mount a mechanised manouvre.

The BEF was ill structured and under equipped. The country that invented the tank did not have an armoured division in France until after the German attack - and then it was frittered way. The 12th and 23rd infantry Divisions were hastily deployed across the old Somme battlefield against the Panzer spearhead,where, lacking anti-tank or other heavy weapons and artillery they were overrun. The excuse is that these were labour battalions that should never have been used as infantry. But they serve as one marker of the fate of the LDV or under equipped post Dunkirk Home forces units.

Tactically the Germans were better trained to co-operate in the uncertain chaotic conditions of warfare. With few exceptions it was the Germans who seized the tactical initiative in every engagement. Even on the Dyle and Escaut canal the non mechanised German infantry held the initative against British formations lavishly equipped, by 1940 standards with light AFVs.

There was a similar pattern in Norway where the Germans out manouvred the under trained and ill equipped British. The proof of the pudding is in 1) the Batholomew report which was quite scathing with respect to British shortcomings. 2) the subsequent development of training in Home Forces.3) the widespread lack of confidence in the British Army shown by some of the most talented junior officers into forming their own private armies - commandos - LRDG - SAS- Paratroops SOE . Read their memoirs. They were embarrassed by the Blimpish Army.

When you use the term "fighting worse" I think you mean has lower fighting power. This is a combination of the physical, conceptual and moral components of power. I don't think anyone doubts the courage or fighting spirit of the Tommy, but guts goes only so far against an enemy out manoeuvred them or used weapons to which they could not respond.

That was the story of British reverses from Norway through France Greece,Crete North Africa and the Far East, Under trained under equipped troops deployed expected to make do and muddle through against a better trained and equipped enemy. The post Dunkirk Home Forces were in the same position. Would they have fought more bravely than the Poles who rode horses against machine guns? Or the French that fought to the last? No one will know.

[Gooner1]

No it wasn't, the plan required a retreat to a defended line followed by an armoured counter-attack.

Oooh, that's a novel one. Presumably you have some garbled misinformation about the importance of the GHQ line.

An example of the orders of the 5th Somerset Light Infantry from 7th September 1940:

INFORMATION:

2. Own Tps
(a) 134 Inf Bde on right. 7 Som L.I. on left.
(b) Under Command:
"C" Coy, 18 (Pr) Bn. R.Fus. approx 150
Detachment Home Guard approx 40
(c) In support:-
275 A.Tk. Bty R.A. (Personnel only) approx 35
374 Fd Bty. R.A. (less one tp)
one Tp 373 Fd Bty R.A.
Det. 273 A.Tk. Bty. R.A. (two 4" guns)
Sec. 338 A.A. Coy R.A.
Naval Bty (4.7" guns)


INTENTION:

4. 5 Som L.I. and tps under comd will:-
(a) Deny the coast to the enemy.
(b) Hold LYDD as a strong point.
(c) Hold BROOKLAND as a strong point.
all positions to be held to the last man and last round.

The battle would have been won or lost at sea and in the air anyway.

The Germans lost the battle in the air, they would have the lost the battle at sea, and would have lost it on the beaches.