aircraft defense capability of battleships and cruisers

[phylo_roadking]

The Ro.43 with 186mph vs Sworfish 138mph

...but it STILL has only ...how many seconds' of inert rifle-calibre ammunition??? Yes, it can overhaul a Stringbag...but not necessarily outmanouver, the Swordfish was noted for being remarkably agile for its weight - and the Ro.43 still has to hit something vital with it's two streams of inert slugs...and unlike the lightweight and relatively weak Ro.43 (the reason it was found unsuitable for sea landings in any sort of swell), the Swordfish was famous for being able to take huge amounts of punishment. A lightwieght Ro.43 is more likely to take more vital damage from a fast-cycling Vickers "K" gun (twin-mount in some versions) than it's liable to do to a Stringbag.

So - once it has expended it's ammunition in driving off or maybe even downing one Swordfish...what does an Ro.43 with no ammunition do about the REST of the attackers???

EDIT: as for the Ro.44, you do know it was regarded as an utter failure by the Italians??? It was so bad, in the end they only bothered building 35 of the 51 originally ordered, and it was retired from front-line service very soon after the start of Italy's war and sent to equip seaplane schools? While the 43 at least remained in service???

[Takao]

Philo, I had always wondered why the four were not converted to carriers once the treaty lapsed. A few things I could think of were: 1) The funds were not available. 2) Dock space/workers not available. 3) Other ship building priorities to precedence. Nothing concrete though, just suppositions. Maybe Mescal might have some answers in this area.

That footnote at Combinedfleet gives us another mystery. Kaigun by David C. Evans & Mark R. Peattie mentions all four as converted and sources Nihon Zosen Gakkai, ed. Showa zosenshi[History of ship building in the Showa era]. Hara Shobo, 1977. But, then again Jon Parshall is the man who would probably know best. Jon even provided several diagrams & maps for their book.

Now you really piqued my interest! Please explain about the Chitose.


How are you doing Dili. 138 mph was, IIRC, the top speed of a Swordfish. You forgot to factor in that the "Stringbag" is lugging around a heavy torpedo, so she is most likely not making 138 mph, maybe 110-120mph. That is on the attack run, then the Swordfish would have to slow down even more to drop her torpedo, I think the drop speed was in the high 80's for the British torp.

[phylo_roadking]

Now you really piqued my interest! Please explain about the Chitose

Oh God. Ask yourself..."do I really really want to...." - http://forum.axishistory.com/viewtopic. ... 1&t=148214

[Takao]

Thanks Philo, I'll give it a look see shortly.

I think Dili really likes the Ro.44. I had mentioned similar information about it back on page 2 in my post on June 29, 2009 @ 6:09 pm.

Edit: Oh god, not that thread! I joined in for a little bit later on, but missed the beginning.

[phylo_roadking]

I'll give it a look see shortly

Yep, that thread. The only "short" thing about it is one's temper...

[phylo_roadking]

138 mph was, IIRC, the top speed of a Swordfish. You forgot to factor in that the "Stringbag" is lugging around a heavy torpedo, so she is most likely not making 138 mph, maybe 110-120mph. That is on the attack run, then the Swordfish would have to slow down even more to drop her torpedo, I think the drop speed was in the high 80's for the British torp.

Strangely enough - for ONCE all the Internet and paper sources I can get my hands on tonight use that 138mph figure...except the Malta Aviation Museum which says...139mph 120mph is indeed listed as it's cruising speed at 5000ft. And I came across an IM comment on one site from a veteran pilot who remembered the approach speed for dropping a torpedo as 85 knots.

But as it's a combat aircraft, I would assume that top speed figure is fully armed with a combat load?

[Takao]

From "To War in a Stringbag" by Commander Charles Lamb

To deliever this weapon in the face of intense opposition in daylight, pilots were taught to attack from a steep dive, at speeds of 180 knots and more. They have been known to reach 200 knots in that dive - in extremis - but there was then a real danger of the wings folding back, or tearing off. In that headlong rush to sea level, the pilot had the impression that he was standing on the rudder bar, looking over the top of the center-section of the upper mainplane. His face was only partially screened, so that a helmet and goggles were a "must" for all normal individuals. Those dives had to be nearly verticle. Any modern clean-surfaced aircraft needs many thousands of feet to pull out of a dive, but the Swordfish could be eased out, with a pull-out of less than five hundred feet. After straightening out and throttling back, the forward speed came right down to 90 knots very quickly, because of the drag provided by the fixed undercarriage, and all the struts and wires between the mainplanes.

Commander Lamb gives a cruising speed of 90 knots. The stall speed he gives is an incredibly slow 55 knots!

[Dili]

EDIT: as for the Ro.44, you do know it was regarded as an utter failure by the Italians??? It was so bad, in the end they only bothered building 35 of the 51 originally ordered, and it was retired from front-line service very soon after the start of Italy's war and sent to equip seaplane schools? While the 43 at least remained in service???

Because they had different missions. Ro.43 had no competitor.Ro.44 had land based fighters better than it.
You are misinformed what was a Ro.44. It was a Ro.43 without a navigator/observer and 2x12.7 machine canonns. It was stopped being build and later taken from service because Italians had much better land based fighters when Cr.42 appeared. If they tought of putting Ro.44 in ships it would be better than an Ro.43 for that kind mission and both were agile planes. Ro.44 was a failure against a Cr.42(even a Cr.32) not against a Ro.43 in fighting mission.

[Ironmachine]

Well, the Italians finally decided to try the trick (i.e, using their ship-borne aircraft to protect their ships), but they also decided that they needed something better than the Ro.43 and Ro.44 and so they began to "navalize" some Re.2000. This may mean something.
The problem with these kind of arguments is that it really no matters how much you argue about the relative advantages of the Ro.43 and Ro.44 versus the Swordfish, you are not going to reach a definitive conclusion. There are just too many variables involved, and nothing short of the real situation is going to prove conclusively if it was feasible or not to defeat an attack of Swordish with those seaplanes.
The only sure thing is that it would have made no harm for the Italians to try it; whether it would have made them any good remains uncertain .

[mescal]

Philo, I had always wondered why the four were not converted to carriers once the treaty lapsed. A few things I could think of were: 1) The funds were not available. 2) Dock space/workers not available. 3) Other ship building priorities to precedence. Nothing concrete though, just suppositions. Maybe Mescal might have some answers in this area.

Well,

The Japanese dockyards were quite busy in the late 30's, but I strongly suspect that the number of building slips or drydocks was not the main limiting factor.
Actually, these conversion took only a relative short time - 6 to 9 months. And a good part of the work could have been done alfoat. So I would say that, had the conversions been seen as critical it would have been possible to find some room in one yard or another to do it.

The manpower in the dockyards would have been a bigger problem, but that's more intuition that data-grounded deduction.

A third limiting factor would be the number of aircraft -- during the last years of peace and the beginning of the war, th IJN did not have many aircraft available (as soon as Midway, the CV airgroup were understrength).

But in my opinion, the real reason is doctrine.
The IJN did not see the need to massively add carriers to its inventory until it was too late. Do not forget that the high command was still fond of battleships, and that carriers were not seen as the main capital ships until late. So a number of cheap seaplane carriers to provide recon for the battleline made perfectly sense.

I'm not sure this is the exact true reason (but I remain pretty sure that the main reason is more doctrinal than financial or technical), but it's an interesting question.
Why were the Japanese unable to come to the conclusion that, when you want to increase the airpower of your fleet, the best solution is a full-length flattop ?
Instead they tweaked with second-rank solutions (Tone "Recon" cruiser, Mogami, Ise ...), when the USN put into service dozens of CVE.
And such merchant-to-CVE conversions would probably have been cheaper for Japan than the complicated work on Ise or Mogami.

[Takao]

Thank you Mescal, I knew if anyone could answer a dockyard question it would be you. And thanks for pointing out about the limited number of Japanese aircraft, I had completely forgotten about that. I believe that "Shattered Sword" by Jon Parshall & Anthony Tully stated that several carrier airgroups were understrength going into battle at Midway. That also reminded me that the Japanese navy was having problems getting enough personnel, especially those of officer ranks. IIRC, the IJN was short some 2,000 officers at the start of the Pacific war.

The two of the tweaks(Tone and Mogami conversion) were doctrinal. The Japansese took a dim view to using carrier aircraft for recon purposes. They felt that using these planes to perform recon work meant that they could not be used to perform an attack. So, to free up the carrier aircraft for attack purposes they built the Tones and converted the Mogami as a seaplane carrier. The Ise class conversions was a stop gap measure to get planes back to the fleet quickly. While a newly built CVE would have been ideal, the Japanese were not known for rapid ship construction. Pertaining to merchant conversions, Japan had already completed converting the Taiyo, while four(Unyo, Chuyo, Kaiyo, and Shinyo) woul begin or complete the process in 1942. Also, could a converted CVE keep up with the fleet? The Ise could make 25 knots, while the fastest CVE conversion(Kaiyo) was 23.8 with the others down around 20-21 knots.

[LWD]

What if any fighters did the British have to escort Swordfish? What was their doctrine in that regard? I'd think if they had a report of Italian float planes in the air they would think about sending a fighter or two in any case.

[mescal]

The two of the tweaks (Tone and Mogami conversion) were doctrinal. The Japansese took a dim view to using carrier aircraft for recon purposes. They felt that using these planes to perform recon work meant that they could not be used to perform an attack. So, to free up the carrier aircraft for attack purposes they built the Tones and converted the Mogami as a seaplane carrier.

That’s precisely this doctrine that I criticize. This led to build Tone and Chikuma as twin-purpose ships, which in the end were not especially good at either of their role:
•When it comes to scouting, they simply did not have enough planes – Midway is telling in this regard.
•If they have to fight as cruisers, the disposition of their turret put them at disadvantage, and they have a lower firepower than their predecessor and in some respect, their protection was a joke. I think they were happy not to encounter anything bigger than a Fletcher-class DD.

If I were to make suggestions –with full hindsight, admittedly – to improve this class, I would propose to completely strip one of them (say Tone) of any superstructure, and fit a full-length flight deck (189m) to have an Independence-like light carrier. You then allocate her with 20 Zero and 10 Kate, all dedicated to Recon, why crews trained accordingly. And you call her Scout-Carrier. So that those admirals remember her role and do not misuse her. Then, and only then, you attach her to the Kido Butai.
Then, you put a strong AA battery on the aft deck of Chikuma, in the space initially dedicated to air operations.

I think that having ships dedicated to one and only one purpose enables to build better ships than trying to pack too many functions in one hull.

Actually, and to come back to the initial question, that’s why I feel that using BB-seaplanes for CAP makes little sense. Sure it’s technically possible to achieve some result, as shown in some posts above. But BBs are not designed nor trained for that.
If a BB is in such a position that launching a seaplane for CAP makes sense, it only proves that someone screwed somewhere.... You simply don’t send BBs under enemy airpower without dedicated specialized CAP.

The Ise class conversion was a stop gap measure to get planes back to the fleet quickly. While a newly built CVE would have been ideal, the Japanese were not known for rapid ship construction.
Pertaining to merchant conversions, Japan had already completed converting the Taiyo, while four(Unyo, Chuyo, Kaiyo, and Shinyo) woul begin or complete the process in 1942. Also, could a converted CVE keep up with the fleet? The Ise could make 25 knots, while the fastest CVE conversion (Kaiyo) was 23.8 with the others down around 20-21 knots.

I do not know how longer or how more costly would have been the Ise conversion if they decided to give them a full-length deck. Perhaps it was too complicated, but I fear that the IJN was not yet ready, even in 1943 to give up the 16*14” guns remaining on the two ships, and decided the specs of the conversion just to keep some big guns.
Regarding conversions, I also wonder why they did not use the three Aganos as Independence equivalent. Agano was fitting out, but Yahagi was still in her building slip and Sakawa not begun when Midway occurred. Those three ships had the size and speed to be relatively good CVLs (I imagine them as slightly smaller Zuihos).
Regarding the CVE, they certainly could not keep with the fleet, but the seaplane carriers Akistushima and Mizuho had a top speed of ~20 knots. And when browsing through the TROMs of the Japanese seaplane carriers, I do not see a mission they did that a CVE could not have fulfilled better – that is, if we exclude the stupid reinforcement runs in the Solomon that cost them the Nisshin.
That’s why I think the 5 CVS (Akitsushima, Mizuho, Chitose, Chiyoda, Nisshin) should have been converted/built from the start to CVE.

Naturally, I’m completely aware that everything I suggested above benefits from hindsight and/or is not technically or financially possible.
But I see it as a thought experiment to show that the IJN used an overly complex way of reasoning. And that, in general, dealing with a limited number of types of (mono-task) vessels greatly simplifies command and control problems.
Which is always quite a good idea.

[phylo_roadking]

What if any fighters did the British have to escort Swordfish? What was their doctrine in that regard? I'd think if they had a report of Italian float planes in the air they would think about sending a fighter or two in any case.

To begin with - Fairey Fulmars and ....the Blackburn Skua! Although the Skua was notably a failure in the role against the LW's performance fighters in Norway, even it's handling and armament would have allowed it to render an Ro.43 unto matchwood The Fulmar was quite sucessful; although slow compared to land-based monoplane fighters, it was effective against land-based bombers in the Med both operating from carriers on Malta convoys and later when the Illustrious' complement was unloaded at Malta and they formed part of the defences there.

Olivier, I agree with everything you say above. E.R. Hooton's opinions about the weaknesses of multi-role aircraft between the wars very obviously read across into ships too!

I knew the conversion of the Chitose was remarkably fast; it had a considerable degree of adaptation already built it, it even had provision for the rapid installation of an elevator designed in when built. The tenders were indeed relatively slow; I presume that even when deck-launching their "ready" aircraft, there was a minimal need to turn into the wind? Certainly, given the positioning of the Chitose's catapaults, it would have been rather difficult to steam INTO the wind! Therefore...I would presume more powerful engines were simply seen as superfluous in that particular application.

The stall speed he gives is an incredibly slow 55 knots!

Takao, with it's sheer square-footage of wing and it's leading edge slats[/i], this was indeed one of the major advantages of the Swordfish. As a type it was known to have taken off from MAC ships on convoy escort without them having to turn into the wind...and even take off from carriers stationary in harbour!

[Dili]

Well, the Italians finally decided to try the trick (i.e, using their ship-borne aircraft to protect their ships), but they also decided that they needed something better than the Ro.43 and Ro.44 and so they began to "navalize" some Re.2000. This may mean something.

Yes but when they started to put them in Littorios there was already much better planes arriving in Med and Re.2000 had not gained much advantage.

The only sure thing is that it would have made no harm for the Italians to try it; whether it would have made them any good remains uncertain[/quote]

I agree.

What if any fighters did the British have to escort Swordfish? What was their doctrine in that regard? I'd think if they had a report of Italian float planes in the air they would think about sending a fighter or two in any case.

True, Fulmar while less agile had an important speed advantage. But that is a stress in British organization plagued by shortages in 1940-41. If British replicate to Italian measures it means also Italians will have a good signal of what is important. They could have perceived the need of Carriers still in 1940.