Thumpalumpacus
Major
The Helldiver always makes me think of the American retort of dismissal: "Sure, when pigs fly."
Japanese aircraft were behind in timing to Allied aircraft.
- Thread starter Shortround6
- Start date
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From 1938-44 the RN commissioned 7 fleet carriers that were fitted with a full complement of aircraft from 1940-44.
The IJN commissioned 6 fleet carriers from 1938-44 " ".
The IJN converted two merchant ships into light fleet carriers; Junyo and Hiyo.
The IJN put 4 CVLs into service from 1940 to 1944.
The IJN put 5 CVEs into service from 1940-44.
Of course the RN, RCN, RAN, etc also commissioned hundreds of Battleships, cruisers, fleet destroyers, and smaller ships into service from 1939 whose combined tonnage and numbers dwarfed similar tonnage and numbers from the IJN."
6 Dec 1941
Relative technology and training
__________________RN__USN__IJN
AW radar__________Y___Y____N
SW radar__________Y___N____N
SW 10cm radar_____Y___N____N
FC AA radar_______Y___N____N
FC surface radar__Y___N____N
carrier radar GCI_Y___L*___N
ASV radar_________Y___N____N
The USN gained most of these systems (except AW radar) via tech transfers from the UK from Sept 1940 onward.
*L = limited
Intensive/realistic Night action training
_____________________Y____N____Y
Flashless powder___Y____N____Y
Reliable Torpedo___Y____N____Y
VL range Torp._____N____N____Y
Naval losses (including /R under repair exceeding 6 months prior and at 6 Dec 1941) from Sept 1939 to 6 Dec 1941.
CV________________3/2R__0____0
BB________________3/1R*__0____0
Cruisers______23/15R____0____0
DD___________83/~30R_1/1R__0
Subs__________33/3R_____0____0
* Additionally QE and Valiant were crippled on Dec 19.
The war in the ETO drained RN resources and delayed FAA development and expansion. Without a European war the RN would be free to reprioritize shipbuilding to focus on the needs of a Pacific war; the Commonwealth economies combined were far greater than Japan's. Japan would never have attacked the Commonwealth if it was not engaged in a major ETO conflict. With no ETO losses the RN and Commonwealth navies would have been far larger than twice the size of the IJN. Even given the historical losses it wasn't till late 1943/early 1944 that the USN surpassed the RN in size.
From 1938-44 the RN commissioned 7 fleet carriers that were fitted with a full complement of aircraft from 1940-44.
The IJN commissioned 6 fleet carriers from 1938-44 " ".
The IJN converted two merchant ships into light fleet carriers; Junyo and Hiyo.
The IJN put 4 CVLs into service from 1940 to 1944.
The IJN put 5 CVEs into service from 1940-44.
Of course the RN, RCN, RAN, etc also commissioned hundreds of Battleships, cruisers, fleet destroyers, and smaller ships into service from 1939 whose combined tonnage and numbers dwarfed similar tonnage and numbers from the IJN."
6 Dec 1941
Relative technology and training
__________________RN__USN__IJN
AW radar__________Y___Y____N
SW radar__________Y___N____N
SW 10cm radar_____Y___N____N
FC AA radar_______Y___N____N
FC surface radar__Y___N____N
carrier radar GCI_Y___L*___N
ASV radar_________Y___N____N
The USN gained most of these systems (except AW radar) via tech transfers from the UK from Sept 1940 onward.
*L = limited
Intensive/realistic Night action training
_____________________Y____N____Y
Flashless powder___Y____N____Y
Reliable Torpedo___Y____N____Y
VL range Torp._____N____N____Y
Naval losses (including /R under repair exceeding 6 months prior and at 6 Dec 1941) from Sept 1939 to 6 Dec 1941.
CV________________3/2R__0____0
BB________________3/1R*__0____0
Cruisers______23/15R____0____0
DD___________83/~30R_1/1R__0
Subs__________33/3R_____0____0
* Additionally QE and Valiant were crippled on Dec 19.
The war in the ETO drained RN resources and delayed FAA development and expansion. Without a European war the RN would be free to reprioritize shipbuilding to focus on the needs of a Pacific war; the Commonwealth economies combined were far greater than Japan's. Japan would never have attacked the Commonwealth if it was not engaged in a major ETO conflict. With no ETO losses the RN and Commonwealth navies would have been far larger than twice the size of the IJN. Even given the historical losses it wasn't till late 1943/early 1944 that the USN surpassed the RN in size.
The SB2C-3 was quite a good aircraft whilst the -4 was really good.
Wild_Bill_Kelso
Senior Master Sergeant
- 3,231
- Mar 18, 2022
Save all this and let's do an IJN vs RN thread
- Thread starter
- #365
Shortround6
Major General
Problem with keeping the fuel tanks in wing was that it needed considerable redesign of the wing.
The F4U-1 was designed when integral fuel tanks were in vogue.
In the case of the F4U that meant the wing leading edge (nose to main spar) structure formed the fuel tank and they just sealed off the appropriate wing ribs and the main spar and used the skin as the fuel tank. Very efficient from a weight standpoint........until...............The Navy wanted self sealing tanks and then the design was toast. Trying to fit the US style of self sealing tanks (like as used in the P-39) meant a serious reduction in fuel capacity, an increase in weight and a decrease in roll response, at least with a fair amount of fuel on board.
The early F4U-1s actually kept the wing fuel tanks (reduced in size) when they put the fuselage tank in. Once they started using drop tanks they took out the plumbing.
Redesigning the wing structure (changing the ribs and wing skinning) to handle the tankage needed was probably more work than what they did.
The Fuselage guns were a bad idea. Perhaps not so bad in 1938-39 but by 1940-41 and when everybody knew the synchronized .50s fired like turtles on sleep aids sticking with that armament layout was a no-go.
2000hp fighter with the same armament as a Buffalo?
F6F with the R-2600 is a huge what if. The R-2600 used was a one off or four? they built a 2 stage supercharger but details are thin. They also built a turbo version, but details on that are pretty sketchy.
No production R-2600 of any series used a two stage supercharger. There is no information on the performance of the two stage engine at altitude.
The two stage engine gained abut 130-160lbs but that was normal.
If I remember correctly it took under 6 weeks to fit the R-2800 engine to the prototype?
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Don't give the RN the short shrift. The IJN was skilled in night fighting. So was the RN. The RN's night fighting ability also included carrier strikes. I don't want to speculate on the outcome of a gun duel at night. I think the RN may have whiffed a night strike in the IO, though I don't remember if I got that from a "what-if" or a "what was" thread. Still, them Swordfish/Albacores with radar pathfinders would outrange an Atago or Mogami, possibly even Yamato.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
I'll get some popcorn.
Thumpalumpacus
Major
Stability issues at low speed were never fully resolved, a problem when the plane lands on an aircraft-carrier. The Brits and Aussies both cancelled significant orders, the Brits specifically for the very poor handling.
It had a host of other, more minor problems. Obviously you're welcome to your opinion, but I stand by my own.
Thumpalumpacus
Major
I think that one will need some jalapeño bacon cheeseburgers and some beer.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Lotta' beer.
Thumpalumpacus
Major
Since the F4F did OK with four guns, having almost twice the HP would be an advantage in early 1942, than having to wait for the redesign. Cowl guns do have the advantage of better reliability and no convergence issues as wing guns have.
You really don't need six .50s for IJN aircraft in 1942, anyway.
Now I'm not saying the redesign shouldn't have been done, but getting a not quite perfect F4U would have been an advantage over having just F4F and F2A by time of Pearl Harbor, while the next model of Corsair could have a new wing without having to relocate the pilot, in 1943.
Wild_Bill_Kelso
Senior Master Sergeant
- 3,231
- Mar 18, 2022
Would have been a lot more stable if they just lengthened it about 3-5 ft
Thumpalumpacus
Major
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
That's assuming that, (A) the USN had intimate details of all Japanese aircraft designs at the time, and (B) the USN was only going to fight Japan (which was was not the case).
Whatever the handling faults of the SB2C/ SBW/ SBF Helldiver they were not behind the cancellations of either the Australian or British orders. Peter Smith dealt at length with these claims in his Crowood book "Curtiss SB2C Helldiver".
For Australia the matter was mired in US/Australian (or perhaps USAAF/RAAF) politics. The final straw was when 5th AF CO Gen Kenney stated in late 1943 that there was no requirement for dive bombers in New Guinea, which led to the Vengeance squadrons, which had performed very well, being returned to Australia in April 1944. With that roadblock in place, Australia, having taken delivery of 10 of the A-25A Shrike version in Nov 1943, sought to cancel the remaining part of the order (140 aircraft) in Jan 1944 as the need for them as Vengeance replacements had evaporated (cancellation was made on 5 Jan 1944). Subsequent brief tests in Australia described its handling as "quite satisfactory". All 10 were returned to US control between Nov 1944 & Jan 1945 for disposal.
Much of what has been written about the Helldiver in British hands goes back to assessments by Eric "Winkle" Brown when he tested it from Oct 1944 in comparative trials with the Douglas SBD-5 Dauntless and Vultee Vengeance that have been widely published. In condemning its handling he also made the untrue statement "..was never flown onto a British carrier by an FAA pilot". But by then the Helldiver's future with the FAA had been sealed.
British interest in a replacement dive bomber for the Skua went back to Jan 1941 and by Nov the XSB2C-1 was shown to an RAF representative. By July 1942 450 were on order. By Nov a lend lease allocation had been agreed starting in March 1943 and building to 30 per month in Sept with a planned total for 1943 of 185 with more following in 1944. These were to come from Canadian Car production. Then came the delays and more modifications to the aircraft. The net result was that 1820 squadron formed on 1 April 1944 with only 9 aircraft, and in doing so became the only FAA Helldiver squadron. Ultimately only 26 SBW-1 were delivered with 2 of those lost on delivery flights.
By Dec 1943 however it seems that the US attitude to allocating these aircraft to Britain had changed. Previous agreements on allocations had gone out the window. Instead Britain was, per correspondence between the First Lord of the Admiralty & Churchill, "...they made an offer of a reduced number of aircraft, sufficient only to cover wastage on aircraft already delivered...". By Sept 1944 it was clear that the future of the Helldiver in FAA was going to be limited with future deliveries, if any could be obtained in light of US opposition, being SBW-3 or -4, and so the question was being asked "..whether it is intended to use the Helldiver I operationally, or only for training, and what modifications are likely to be required". Accordingly the decision was taken to disband 1820 on 16 Dec 1944.
Contrary to Eric Brown's statement, 1820 squadron's FAA pilots did take the Helldiver to sea on the escort carrier Speaker for a couple of days at the end of Oct 1944 for deck landing training.
As an indication of just how much different test pilot's views of the Helldiver could differ Peter Smith included two examples
Group Captain C Clarkson tested one at Pax River in April 1944 "to test its general handling and to obtain data for pilot's notes. He made no attempt whatsoever to assess the operational role or efficiency".
"Despite the fact that this aircraft has spent many months in development, it does not appear that any attempt has been made to try and give the pilot a good instrument layout or a comfortable cockpit, and for a machine which has done as much flight testing as this type, the lateral control is a disgrace...". But his overall verdict was then "...easy to fly, and inexperienced pilots could probably take considerable liberties with it. The stall characteristics are satisfactory and the landing and take-off very easy."
Lt Cdr G R Callingham submitted a much more detailed report while at Pax River in April 1944 and his final verdict on the SBW-1 Helldiver was
"...the Helldiver is a useful military weapon with a good striking power but not outstanding performance. Easy to handle, it should present few problems in the formation and training of squadrons. The Fairchild-produced aircraft appear to be better made than the Curtiss or Can Car models in general workmanship and finish. This point is made in view of possible future allocations to Britain."
With a folded height of 16ft 10in and folded width of 22ft 6.5in the Helldiver was too large for the lifts and hangars of the armoured carriers. It could however have been operated from the light fleet carriers ordered in 1942. But the earliest planning for these would not have seen the first 4 light fleets in service until the second half of 1944. I suppose that would have fitted with initial deliveries planned for the latter part of 1943 with squadron formations following on from that.
The spec that led to the Helldiver read (with my emphasis):-
"The limiting overall dimensions shall be those which will permit handling the airplane with wings folded on an elevator 41 feet by 48ft with a clearance of not less than 12 inches all around. However, minimum dimensions are of great importance. Attention shall be be given to the possibility of handling two airplanes on an elevator of these dimensions."
Folded with was 22ft 6.5in. So 2 on the lift soaks up the 48ft dimension stipulated.
Even with the lift limitation, the Helldiver (length 36ft 8in) could have been a few feet longer, as in fact its competitor in the contest was (Brewster SB2A Buccaneer at length 39ft 2in).
The odd thing with this is that when this was issued in June 1938 only the Lexingtons & Ranger had lifts that small. With the construction of the Yorktowns and then Wasp in progress the USN had moved to a larger 48x44ft lift platform which was repeated in Hornet and the Essex class in 1939/40. Using those as the limitation would have allowed some further relaxation in the length of the Helldiver up to approx 42ft.
So it seems "minimum size" trumped elevator size.
- Thread starter
- #379
Shortround6
Major General
This assumes they built more than 6 two stage R-2800s in 1941.
It also assumes they would have built the 4 gun F4U while they planning the 6 gun F4F-4 at the same time.
They had completed 5 F4F-4s in Dec 1941.
Nov 28th saw the Navy requesting major changes
The XF4U-1 didn't pass the Demonstration tests until Feb 25th 194, contract negotiations were finished in April, signed contract was June 30th 1941.
The first production F4U-1 was completed June 25th 1942.
Now here is a real problem, they never changed the XF4U-1. It always had the forward cockpit and the 4 guns.
The changes didn't delay things as much as is thought.
You also don't have working two stage 2000hp engine until until the end of 1941.
The XF4U-1 used several prototype engines that were rated at 1850hp max and were based of the A series engines and not the B series.
The Japanese approach to carriers is interesting because they realised long before they went to war with the US that they couldn't outbuild them in the event of war. So they developed a "shadow" carrier program (ships that in the event of war could be quickly converted to carriers) that led to many of the ships mentioned above.
Auxiliaries designed for conversion - Zuiho (conversion completed Nov 1940), Shoho (converted 1-12/41), Ryuho (converted 12/41-11/42) Chitose & Chiyoda (both converted in 1943) (plus Mizuho lost before conversion)
Subsidised merchant ships - 10 vessels (3 in 1926; 3 in 1937; 2 in 1938; 2 in 1939). Of these 4 were lost in WW2 before they could be converted. The 1937 ships became the escort carriers Taiyo (converted 2-9/41); Unyo (converted 11/41-5/42) and Chuyo (converted 7-11/42). One of the 1938 ships became the Kaiyo (converted 12/42-11/43). The 1939 ships were larger and faster and were taken over secretly while under construction in Oct 1940, completing as carriers in May & July 1942 as Junyo & Hiyo.
The final escort carrier, Shinyo, was converted from the German liner Scharnhorst stranded in Japan on the outbreak of WW2 and sold to the IJN. She was converted 9-12/43.
Note just how many of these ships had at least begun conversion before Pearl Harbor.
The first 3 IJA "carriers" noted were little more than aircraft transports. They had provision for aircraft to take off but not land. Yamashio / Yamashiro Maru (sources differ as to the exact name) and Shimane Maru were completed too late to see service as carriers. Again the flight deck on the former was only 351ft long and her intended airgroup was 8 Kokusai Ki 76 high winged planes carring 2x60kg depth charges.
Having laid down the Shokaku pair in 1937/38 (completed just in time for WW2 in Aug/Sept 1941), there was a long wait for the next fleet carrier to be laid down, Taiho, in 1941 due to pressure on the shipbuilding industry. But with war looming the Japanese realised they needed to prioritise a smaller class so designed the Unryu class in late 1941 as a modified Hiryu, although construction did not begin on them until after Midway.
It is interesting to contrast the Japanese activity in 1940/41 with that of the USA. As of 3 Sept 1939 the USA had 5 carriers in service (Langley CV-1 had been converted to a seaplane carrier by then). Wasp was under construction and Hornet had been ordered but was only laid down later that month. While it ordered 11 Essex class in 1940, only 5 had been laid down by PH (2 of those only the week before) and due for completion between 1944 & 1946. The only other carrier built 1940/41 for the USN was the CVE-1 Long Island.
They did of course start conversion of 6 ships for the RN, Archer completing before PH, and Britain agreeing to return Charger to the USN for use as a training carrier to train both USN and RN pilots.
But the big CVE program did not kick off until Jan 1942. The CVL project promoted heavily by FDR and opposed by the USN in the latter part of 1941, finally got the green light in Jan 1942.
