Axis Carriers

A standard amphibious cruising formation in the 1960s was 2000 yards P&S. Don't remember the fore and aft distance. Woe betide the OD who couldn't keep station at 2000 yds when the entire formation was moving at a speed of around 16 to 17 knots. Standard turning circle for an AKA or APA was 2000 yds and stopping distance was around a mile and a half.

Want to approximate the experience? Find a patch of glare ice and drive a rear wheel drive car on it when there is a day with a strong wind. Do not use your brakes. Try driving at a moderate speed and you will quickly understand what maneuvering a big single screw ship would be like.

Distances at sea are deceptive.  First off, ships, even lumbering merchantmen (perhaps especially lumbering merchantmen) need quite a bit of room to maneuver--stopping and turning distances are measured in hundreds, even thousands of yards.  "Fog Distance" closed convoys up to 2000 yards (apx 1 nautical mile) fore-and-aft, and 1000 yards P&S.  This is "danger close" to use the artillery parlance.

At 8kts, a ship covers 266 yards per minute.  if the ship in front of you loses power or steering and you put your own helm over in fog conditions, you are 1/4 way to the next convoy file in just 60 seconds.  That gives you about 60 more seconds to reverse your helm and try to get back on a parallel course.  And, that, only if the ship ahead has not fallen out of line in the same direction as you steered to avoid her.

So, yes, a 20 ship convoy at 2 mile separation is a big block, about 10 x 10 miles.  But, escorts with 14-15kt cruise speeds can easily circle an 8-9kt convoy.  That, and escorts do not merely march alongside a convoy like a sergeant minding a company.  Instead, they are stood out away from the convoy where their sensors  work best, where their weapons have the greatest fields of fire.

So I found Fi-167's in both 1/72 and 1/285!

Funny that, the 6mm model. Must be for war games.

I don't believe ships in convoys were 3 to 5 miles apart.  That would make darn near impossible for the escorts to protect when you have that many ships.  

One must remember it's not the top speed that matters, but the cruise speed.  That speed which maximizes range per fuel use.  Many of the Atlantic convoys were limited to 10-12 knot cruise speeds, which are significantly slowed by zig-zag*.

Hardest part for an attacking submarine is calculating the best course and speed away from detection from a given convoy, so that the submarine could then surface and use it's best speed to an intercept point.  (Even better was to have a code intercept that could simply place a submarine in the known path of a convoy, where it could wait, doggo, until the targets presented them selves.

LIners, like Queen Mary were designed to cruise at high speed--shaving a day or two off a transatlantic passage would pay for itself in passage fares.  A sub with a top speed around 18-19kt could not  maneuver enough to catch 18-22kt liners, unless they were very lucky (and the liner stayed at cruise speed only--trips to/from Blighty could be achieved without emptying the fuel bunkers at near top speeds, 25-28kts).

With more modern subs, which are faster underwater than surfaced, change the calculus.

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*Zig-zags are not simple routines, even if submariners discount their utility.   The zigs & zags were planned out in advance, and published as a set of offsets from base course.  So, a plan might be to run xxx miles at nn speed at dd ±Base Course.  The next leg would be at some other angle, at a different speed, and distance, and so on.   This could be 11nm at 09kt at  BC -55º, with the next leg 21nm at 11kts at BC+20, then followed by a leg of 2nm at 10kts and BC-25º.

This makes for a certain randomness.  Even better plans allow variances too--which can be delivered in plain speech--"Mike Corpen ALFA DIST 01 COURSE NEG 02 SPEED 0" which will not mean anything unless one knows that means Zigzag plan A, change distance plus 1; angle -12º; no change in speed.

However, with a long enough observation radius and duration can be sorted out.  The three-dimensional calculus of torpedo aiming was second nature to submariners, which meant they could visualize the target course with some chart paper and a slide rule.  That the target convoys could be 20, 30, even 40 ships makes for a sizable thing to spot on the ocean, what with spacing from 3 to 5 miles between convoy ships.

Even faster warships and convoys were caught, especially if zig-zagging.  Sub would just plot the base course and drop over the horizon and execute the end around and lie in wait.  24-25 knot zigs would be caught by 18-19 knot end arounds.  Granted it would take time.

According to most submariners, there are two types of ships.....subs and targets. Even more true today with the advance in weapons available.

Faster ships and submarines.

Marcus,

I'm not sure about the types that you are referring to.

Bill

Sure they do that why the build both types and still do.  Its on heck of a game to play.

And yet, Shinano, Taiho, and Kongo were traveling faster than the boats that sank them. Speed might mean a smaller envelope, but it is possible for a submerged and slower diesel electric submarine to sink a much faster surface ship in spite of their superior speed. It has happened time and time again. Granted, faster ships have an advantage, but so do submarines.

Bill

There were no targets for them in the Atlantic once all the raiders and supply ships were discovered and destroyed by 1940-41.  All of those were sunk by surface ships.

True....Any sub was looked at as the other sides.  Even cases of our boats leaving Pearl and getting bombed by aircraft even when escorted by DD's

Probably most of the reason the Brits and USA did not operate in the Atlantic.  That way the convoy escorts did not have to worry about a blue on blue incident.

Not entirely true Bill - speed means a smaller envelope where a shot is possible and much less time to plan it out. How many times was RMS Queen Mary hit while crossing the Atlantic?

Also, the nature of the campaigns being fought in the Atlantic and Pacific makes it much harder to make a direct comparison. Moving Allied submarines into the Atlantic would have made convoy protection a lot more difficult.

Marcus,

American submarines sank the faster carriers Taiho and Shinano, and sank the fast battleship Kongo, as well as quite a few much faster destroyers and cruisers.  A given ship's speed is irrelevant beyond serving as another data point for a spread of torpedoes, unless the submarine is engaged in a stern chase.  However, if the target ship is zigzagging, all the submarine has to do is to anticipate the next movement and cut the distance by cutting across the maneuvering ship's zig.

Bill Morrison

Tracy,

Also, whereas the Germans had done little or anything to develop any suitable aircraft for carrier operations, the Americans were able to help the British by providing such aircraft for their carriers. Neither the Bf109 or the Ju87 had the structural strength necessary to operate from carriers at sea, especially in the North Atlantic.

Bill Morrison

Most British subs were deployed in the Mediterranean, Pacific, North, Norwegian sea.  Besides at the speed she was traveling at it would have an long shot that a sub would get a chance at her.

The IJN knew that without air superiority, the capital ships were sitting ducks for aviation assets. This after the sinking of the British capitals right at the beginning of the war.

After Midway, the experienced air assets were basically gone, because as was stated, they did not rotate experience back to teach.

I suspect that that is why most of their battle fleet sat idle until they absolutely had to deploy to try and halt allied advances.  Then we shut off most all of the oil coming in by declaring tankers primary sub targets, and really kept them at dock side.

What if any ASW capabilities did the Germans have, beyond the usual stuff for ships in harbor or within range of land based aircraft?

For instance, I've always wondered why the British didn't deploy submarines to sink the Bismark once she was at sea.

Was it just too far, too soon to get the forces assembled?

Because without destroyer screens, I can't see the Bismark, or fpr that matter the GZ, as more than the proverbial sitting duck.

Even had Graf Zeppelin made it out to sea, she would have had a completely green air group. The Germans did not have any experience in carrier aviation and how to properly spot and launch decks, much less how to best employ a single carrier.

GMorrison

the Baron

I've got a pair of the Revell kits in my stash, for a what-if German naval aviation build.

I agree that given the way naval aviation played out, especially in the Pacific, the Germans might have been hard put to keep their carriers alive, once the war got underway.  However, I think you can argue a counterfactual, based on a couple of premises:

• they had completed the Graf Zeppelin before the outbreak of the war
• they sent her to an overseas station, prior to the outbreak, as they did with other vessels
• they used her in concert with their other capital ships, such as pairing her with the Bismarck or Tirpitz, and a heavy cruiser or two--in effect, a task force

This from Wiki:

Said Mitscher: "The ideal composition of a fast-carrier task force is four carriers, six to eight support vessels and not less than 18 destroyers, preferably 24. More than four carriers in a task group cannot be advantageously used due to the amount of air room required. Less than four carriers requires an uneconomical use of support ships and screening vessels."^[2]

Sure, but did he say that in 1939, or in 1944?  At the time the Germans were building the GZ, there was very little practical experience with integrating carriers into the fleets, everyone was still learning.  Kido Butai was really the first practical example of a carrier task force, along the lines that Mitscher describes and that we adopted into our doctrine.   My counterfactual has as a precondition that the level of knowledge and experience with using carriers is the same as it was historically.

Marcus,

Agreed.  And, they would have had to overcome their other nemesis, the Royal Navy. People assume that the British would have sat still while the Germans built their battle fleet. In addition to the five ships of the KGV class, which in many critical attributes were superior to the two ships of the Bismarck class, the British had the five ships of the Lion class on the planning boards, among many other types as well.  While Germany struggled to complete the Zeppelin and the Seydlitz, the British were having no difficulties completing the ships of the Illustrious class, the Ark Royal, the Colossus Class, as well as the escort carriers. The British would have had little trouble maintaining their naval superiority over the Germans even had Hitler been able to complete the "Z" Plan.

Bill

Didn't do much in that war either. Every ship but one got sunk at the Falklands.

Jutland got chased back into port.

Committed suicide at Scapa Flow

Bill,

If Reader only had five to eight more years to build the Kriegsmarine as it was in WWI.  But they would still have to overcome their nemesis "the Denmark Straits".

Marcus

Tracy,

I am certainly not making excuses for the Kriegsmarine.  It certainly was not an awesome force, nor were its ships better than their counterparts in other navies. In many ways they were decidedly inferior.  My argument is that the German capital ship force did not merely sit idle. It did fight but it was overcome by superior force.

Bill Morrison

Marcus,

It depends on what you mean by "better showing".  For example, the German U-Boat campaigns had the Allies on the roles through early 1943 before technological advances and Enigma tipped the scales decisively. The IJN had the Allies on the ropes until June, 1942, when the USN won decisively at Midway. Between June and into 1943, the IJN and USN were stalemated until late 1943 when the USN gained the ascendancy.  After the late 1942 and mid-1943 period in the Solomons, the IJN was soundly defeated.

The IJN made many errors in judgment, beginning with the attack on Pearl Harbor in the first place. True, their carriers ran rampant for several months, but the USN did recover fairly quickly.  Except for the four Kongo's, the IJN battleship force largely sat idle when they could have been used. The IJN never seriously conducted a submarine war. The IJN failed to improve their fleet to effectively compete with the USN, much as the Germans failed to develop theirs, which brings us back to the Graf Zeppelin.

Could the Zeppelin have made a difference? It depends. Would she have been supported by other carriers?  The conversion of the Heavy Cruiser Seydlitz could have helped, but much depends on how that force would have been used. For example, the Japanese certainly had a large submarine force, but it made no difference to the war effort beyond sinking a few American warships. The IJN had no real strategic or tactical plan for them. The Germans had no real strategic or tactical plan for the Kriegsmarine beyond their plan of "guerre de course".  The Zeppelin was an interesting ship, but what was the plan for her use?

Bill Morrison

the Baron

I've got a pair of the Revell kits in my stash, for a what-if German naval aviation build.

I agree that given the way naval aviation played out, especially in the Pacific, the Germans might have been hard put to keep their carriers alive, once the war got underway.  However, I think you can argue a counterfactual, based on a couple of premises:

• they had completed the Graf Zeppelin before the outbreak of the war
• they sent her to an overseas station, prior to the outbreak, as they did with other vessels
• they used her in concert with their other capital ships, such as pairing her with the Bismarck or Tirpitz, and a heavy cruiser or two--in effect, a task force

This from Wiki:

Said Mitscher: "The ideal composition of a fast-carrier task force is four carriers, six to eight support vessels and not less than 18 destroyers, preferably 24. More than four carriers in a task group cannot be advantageously used due to the amount of air room required. Less than four carriers requires an uneconomical use of support ships and screening vessels."^[2]

Once again showing that if it's German, people think it's awesome and will create all sorts of excuses for it.

I've also wondered about the Stuka wingfold design--when did Leroy Grumman come up with his folding mechanism for the F4F?  Was he first, and the Germans got wind of it?  Or did they both come up with basically the same mechanism independently of one another?  After all, it's not so outlandish, just different from the more conventional method (conventional at the time) of a fold along a line perpendicular to the leading edge, and up and in towards the fuselage?

I've got a pair of the Revell kits in my stash, for a what-if German naval aviation build.

I agree that given the way naval aviation played out, especially in the Pacific, the Germans might have been hard put to keep their carriers alive, once the war got underway.  However, I think you can argue a counterfactual, based on a couple of premises:

• they had completed the Graf Zeppelin before the outbreak of the war
• they sent her to an overseas station, prior to the outbreak, as they did with other vessels
• they used her in concert with their other capital ships, such as pairing her with the Bismarck or Tirpitz, and a heavy cruiser or two--in effect, a task force

I think her air wing would have been the equal of any single carrier the Royal Navy could throw at her.  Remember, too, that in 1939, some of the developments in naval doctrine had to be thought out, that came into application by 1940.  Even the Japanese hadn't come up with the idea for the First Mobile Striking Force till 1940 (Genda's revelation) and didn't implement it till April 1941.  There was still a lot of inertia, and inexperience, with using carriers, in navies that all still thought of the battleship as the primary offensive naval weapon.  I wonder, for example, if the Graf Zeppelin had been with the Bismarck and the Prinz Eugen, what impact she might have had.

Any scenario does have to deal with the fact, though, that in the end, the Germans did not have the resources to withstand all of the countries eventually drawn into the war against her, any more than the Japanese did.  The best they could do was fight to a draw, with her enemies' prospects of fighting their way back too costly to consider.