Defeating Invasion Fleets

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nuyt
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Re: Defeating Invasion Fleets

Post by nuyt » 14 Feb 2023 14:28

What about a simultaneous air and submarine attack on the invasion fleet? The ships will be busy evading torpedoes in the water AND bombs (and torpedoes) from the air. Panic and friendly collisions cannot be ruled out.That should devastate an invasion fleet or at least scatter it and thin it out. Next follow up with your surface vessels, while your subs are still around. Follow up air attack also needed on the remaining escorts.

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Re: Defeating Invasion Fleets

Post by T. A. Gardner » 14 Feb 2023 16:23

nuyt wrote:
14 Feb 2023 14:28
What about a simultaneous air and submarine attack on the invasion fleet? The ships will be busy evading torpedoes in the water AND bombs (and torpedoes) from the air. Panic and friendly collisions cannot be ruled out.That should devastate an invasion fleet or at least scatter it and thin it out. Next follow up with your surface vessels, while your subs are still around. Follow up air attack also needed on the remaining escorts.
Three U-boats did attack one of the Torch landings in N. Africa and managed to sink like 4 transport ships and damage two more at Fedhala for the loss of one boat (U-173). These also arrived after the landings had already been affected, so they had little impact on the amphibious operation. Coordinating an air and submarine attack would be difficult in any case as the subs would have only spotty communications with the command coordinating the attacks, and likely no communications with aircraft tactically.

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Re: Defeating Invasion Fleets

Post by Carl Schwamberger » 14 Feb 2023 16:35

nuyt wrote:
14 Feb 2023 14:28
What about a simultaneous air and submarine attack on the invasion fleet? The ships will be busy evading torpedoes in the water AND bombs (and torpedoes) from the air. ...
The examples we have are on the less successful side. Off Luzon in 1941/42 the US subs & air failed. Ditto for the assorted invasions of the Dutch East Indies. This may have had a lot to do with numbers, tho there are good arguments the weapons and tactics were inadequate.
T. A. Gardner wrote:
14 Feb 2023 02:48
Off Salerno they proved reasonably effective, but the Luftwaffe simply could not put up the sort of force necessary to cripple the invasion fleet offshore. KG 100 proved capable of launching attacks using Fritz X there, but they lacked the numbers to really make a dent in Allied landing forces. The same goes for the Anzio landings.
Yes the numbers don't add up. Similarly the Axis air forces made some spectacular attacks on the invasion fleet of op HUSKY, but the ship numbers seriously damaged were minuscule.

LST-313, minesweeper USS Sentinel,USS Maddox, Indian hospital ship Talamba were sunk on 0 or D Day of HUSKY. IIRC a ammunition transport was among those sunk on D +1. But given the size of the Allied combat and transport fleet committed to the invasion these losses amounted to maybe 2% of the total. However I have to refer back to the Wake Island, Midway, & the April attempt at Milne Bay. In those cases the landing operation was canceled after some ships of the covering force were sunk, & none of the transport fleet. Here Napoleons observation about the relative importance of the mental to the physical may be a guide.


Operation ICEBERG @ Okinawa in 1945 is worth a look. There the Japanese had a mass deployed anti ship missile in the form of the Kamakaze dedicated aircraft. The result was 368 Allied ships—including 120 amphibious craft damaged & 36 ships—i15 amphibious ships and 12 destroyers—were sunk. US Navy dead had 4,907 killed and 4,874 wounded, mostly from air attacks. While the Navy leaders were upset about this any ideas about aborting the invasion were dropped. The invasion of Leyte was also opposed by a large scale air attack & naval losses were not insignificant. Still there was not a debate over aborting the invasion.

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Re: Defeating Invasion Fleets

Post by Carl Schwamberger » 14 Feb 2023 16:38

T. A. Gardner wrote:
14 Feb 2023 16:23
... Coordinating an air and submarine attack would be difficult in any case as the subs would have only spotty communications with the command coordinating the attacks, and likely no communications with aircraft tactically.
Yeah, coordinating that at the tactical level in 1942 or even in 1954 sounds difficult. Best you can do in that era may be pre planning, or operational coordination.

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Re: Defeating Invasion Fleets

Post by Richard Anderson » 14 Feb 2023 16:54

T. A. Gardner wrote:
14 Feb 2023 16:23
Three U-boats did attack one of the Torch landings in N. Africa and managed to sink like 4 transport ships and damage two more at Fedhala for the loss of one boat (U-173). These also arrived after the landings had already been affected, so they had little impact on the amphibious operation. Coordinating an air and submarine attack would be difficult in any case as the subs would have only spotty communications with the command coordinating the attacks, and likely no communications with aircraft tactically.
I make it six U-Boot sinking one escort and four transports, and damaging one transport from 9 to 14 November. One of the transports was crippled by a torpedo hit from an attack by III.KG 26 before the sub finished her off. All of the transports had emptied their cargoes before being sunk so it had zero effect on the landings. Of the subs, one was sunk 17 November.
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Re: Defeating Invasion Fleets

Post by nuyt » 15 Feb 2023 13:53

T. A. Gardner wrote:
14 Feb 2023 16:23
Coordinating an air and submarine attack would be difficult in any case as the subs would have only spotty communications with the command coordinating the attacks, and likely no communications with aircraft tactically.
Well, by the standards of the day, they could do the following. Position the subs near the invaders, either lurking in wait or shadowing the fleet. They would come into action (previously agreed between Navy and Air Force) when they see (or hear) the air attack. That's close enough for coordination. Not by the minute, but certainly workable. Your surface fleet steams into visual contact shortly after (or perhaps before), luring away the invader's escorts. With a bit of luck (weather, currents) this can be done.

You need air control, which in the case of the NEI was already lost when Java was assaulted, with available submarine elements already depleted by earlier actions.

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Re: Defeating Invasion Fleets

Post by nuyt » 15 Feb 2023 14:09

Peter89 wrote:
11 Feb 2023 22:00

The outcome of an amphibious invasion was not depending on whether the attackers would be sunk on the sea or on the shores. Let's say you put ashore 100 men which has to face 1000 men on the shores. The 100 men is going to win because they were not sunk on the sea? Or alternatively, if the defender has control of the air, let's say 1000 aircraft vs 100 aircraft of the attackers. Again, who's gonna win? Also if the defender has firepower superiority, let's say 1000 guns and the attacker manages to bring ashore 100 guns of the same caliber, who's gonna win?

The reason why the Axis failed to stop the aforementioned amphibious invasions was not because they didn't sink the Allied ships on the sea. It was because they were quantity/quality inferior, the Allies had control of the air, they had plenty NGFS and the favourable defensive position could not offset these advantages.
In the DEI the Japanese forces that landed (always far from the coastal defenses, never into the fire) used fast mechanized spearheads of around 1500 men each, lightly armed on top of that. Yet, they were determined and had air superiority. Without the latter you don't land. The Dutch on Java had the numbers and more than enough firepower to fight those spearheads and they tried. But without air cover, forget it. A well equipped armored column set off to retake Kalijati AB was wiped out from the air.

And morale was at a low after the unthinkable fall of unsinkable Singapore. The British in Malaya had surrendered, the US in Phillipines had lost and the Australian divisions that were promised no longer on their way.

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Re: Defeating Invasion Fleets

Post by LineDoggie » 16 Feb 2023 00:20

T. A. Gardner wrote:
11 Feb 2023 19:52

That proves my point. A amphibious invasion has to be defeated at sea, not after it arrives and lands. Using air power or sea power, or both, to attack and destroy the enemy's amphibious landing forces has to occur while they are still at sea. You can't beat them once they arrive and land.
And yet the Japanese were defeated on land at Guadalcanal
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Re: Defeating Invasion Fleets

Post by Carl Schwamberger » 16 Feb 2023 12:06

LineDoggie wrote:
16 Feb 2023 00:20
T. A. Gardner wrote:
11 Feb 2023 19:52

That proves my point. A amphibious invasion has to be defeated at sea, not after it arrives and lands. Using air power or sea power, or both, to attack and destroy the enemy's amphibious landing forces has to occur while they are still at sea. You can't beat them once they arrive and land.
And yet the Japanese were defeated on land at Guadalcanal
Ditto at the second Japanese landing in Milne Bay to secure Port Morsby & the satellite airfields. Theres some other examples. I ordinarily don't count the battles on Guadalcanal as opposed amphibious assaults, but there were some points in the campaign that are pertinent. Specifically the Japanese ground force starved because the transport fleet suffered unsustainable losses.

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Re: Defeating Invasion Fleets

Post by gebhk » 16 Feb 2023 12:56

This is a most peculiar debate. Just as in defending against any other military offensive operation, you don't have to defeat the enemy at sea or on the beaches or inland, you have to defeat them period - or at the very least achieve stalemate. This can, of course, be done by defeating any one of the three steps (concentration, attack, exploitation) in detail. However any sane plan will involve attacking each stage in turn if at all possible. While examples of an attacker failing by being attacked at one stage alone are to be found with some effort (the Ihantala fighting might be, at a stretch, classed as such), they are the exception and not the norm.

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Re: Defeating Invasion Fleets

Post by Orwell1984 » 16 Feb 2023 17:28

The Kerch landings of 1941 and to a lesser extent 1943 do show how a poorly planned and supported amphibious operation can be defeated by a quick reacting and prepared defender.

In both cases, control of the airspace and the ability to bring concentrated firepower while limiting the attackers ability to reinforce the landing sites was central to any defenders success.

In 1941 it was a complete Soviet defeat.
In 1943, one bridgehead was wiped out, while one remained intact. So a partial example!

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Re: Defeating Invasion Fleets

Post by Carl Schwamberger » 16 Feb 2023 17:59

Orwell1984 wrote:
16 Feb 2023 17:28
The Kerch landings of 1941 and to a lesser extent 1943 do show how a poorly planned and supported amphibious operation can be defeated by a quick reacting and prepared defender....
The key does appear to be the damage to the supporting transport fleet. In that repect theres a paralle to the Guadalcanal campaign. An inability to adequately supply the lodgment that fatal weakens the ground force. Maybe some in depth accounts would indicate otherwise, but thats how it looks from the brief online summaries. ie It may be a better quality ground force would have survived, but I cant say at this point. If numbers can be found for the size of the transport fleet & those sunk/aborted then theres something to compare with high loss operations like the Leyte or Okinawa landing ops.

What is clear is the three examples aborted before the landing force disembarked; First Wake, Midway, first Milne Bay. Occurred when key parts of the combat fleet were damaged or sunk. The transport fleet had negligible damage, so not directly comparable. The Balikapan & Sunda Strait landings illustrate how timing offsets straight forward loss of hulls. In those two cases the cargo ships present were largely unloaded and their loss had no direct impact. Had those same ships been sunk 24 hours earlier the effect may have been very different.

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Re: Defeating Invasion Fleets

Post by thaddeus_c » 20 Feb 2023 15:25

Carl Schwamberger wrote:
16 Feb 2023 17:59
The key does appear to be the damage to the supporting transport fleet. In that repect theres a paralle to the Guadalcanal campaign. An inability to adequately supply the lodgment that fatal weakens the ground force. Maybe some in depth accounts would indicate otherwise, but thats how it looks from the brief online summaries. ie It may be a better quality ground force would have survived, but I cant say at this point. If numbers can be found for the size of the transport fleet & those sunk/aborted then theres something to compare with high loss operations like the Leyte or Okinawa landing ops.
my prior posting was about any new tactic or weapon used to blunt an invasion, but have not had a chance to circle back to that.

my question(s) are on Overlord specifically (it could apply more to the Anzio landings), it was within the resources of Germany to build mini submarines but the KM was pursuing the huge Elektroboote.

if the development cycle was moved up there would be proper minisubs and Type XXXIII coastal Elektroboote to contest Allied landings

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Re: Defeating Invasion Fleets

Post by glenn239 » 20 Feb 2023 15:39

thaddeus_c wrote:
20 Feb 2023 15:25

if the development cycle was moved up there would be proper minisubs and Type XXXIII coastal Elektroboote to contest Allied landings
IMO, submarines did not have the numbers or operational tempo to have caused a major Allied late war landing to fail. The scale of Allied shipping resources available was simply too great even assuming hundreds of such small submarines. (The Allied bomber force would devastate their operating bases as well, like they did with the German S-boats in Normandy).

The V-1 was built in sufficient numbers and had the range, speed and payload that it might in conjunction with stronger reserves might contain then defeat a major invasion, but it lacked the necessary guidance system. Ditto for the V-2, which was fairly useless as a strategic weapon, but lacked the technical means to become a devastating anti-invasion system.

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Re: Defeating Invasion Fleets

Post by thaddeus_c » 21 Feb 2023 05:34

glenn239 wrote:
20 Feb 2023 15:39
thaddeus_c wrote:
20 Feb 2023 15:25

if the development cycle was moved up there would be proper minisubs and Type XXXIII coastal Elektroboote to contest Allied landings
IMO, submarines did not have the numbers or operational tempo to have caused a major Allied late war landing to fail. The scale of Allied shipping resources available was simply too great even assuming hundreds of such small submarines. (The Allied bomber force would devastate their operating bases as well, like they did with the German S-boats in Normandy).

The V-1 was built in sufficient numbers and had the range, speed and payload that it might in conjunction with stronger reserves might contain then defeat a major invasion, but it lacked the necessary guidance system. Ditto for the V-2, which was fairly useless as a strategic weapon, but lacked the technical means to become a devastating anti-invasion system.
was posing that development of the smaller subs against the resupply of Allied forces, not stopping the landings (the same may be true of both, but I was alluding to the former.)

my speculation would be for V-1s powered by conventional "disposable" jets, the same for the Mistel "piggyback" aircraft.

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