Hawker Hurricane Mk. IIB vs. Grumman F4F-4 Wildcat

[Conslaw]

The problem with using weight of fire to determine whether more guns or more bullets is better is that weight of fire presumes that each bullet in a stream is of equal importance. The US Navy and Marine norm was deflection shooting where the pilot started firing in front of the enemy aircraft and fired through the target. You have more leeway in your timing if you have more ammunition. You also are making inherent assumptions about how many shots you are going to get on a target per mission. If you assume that you will only get one shot at one target, six guns is probably better. From the British perspective in ordering the 6-gun Marlet (what would become the F4F-4), they were looking at encounters with slingle FW Condors and U-Boats, primarily. Six guns made sense for the British. For shooting at manouvering fighters, Thatch's preference for 4 guns and more bullets makes sense.

 

[Shortround6]

The British ordered the six gun Martlets in the summer of 1940, The FW 200 had gone into service in April of 1940 (6 of them) flying from Danish bases, By mid may only two were serviceable. The unit was withdrawn from action in June , requiped and sent to Bordeaux-Merignac in July.
There may be a little bit of cross over there but thinking that the Martlet (with 6 guns) was intended to be an anti Condor plane may be pushing things. The CAM ships don't show up until the Spring (May) of 1941 for example.

My own theory is that when the Martlets were ordered, the .50 cal Browning was still a 600rpm machine gun (at best). The British are used to eight guns firing 1100-1200rpm each although smaller bullets. At some point in 1940 the .50 cal Browning was improved to around 800 rpm so that four guns could deliver almost the same firepower as six of the original guns. The US Navy never used the slower firing guns in combat ( the existing guns could be modified with a parts kit).

I have also repeated (many times) the fact that 1940 .50 cal ammo was NOT the same as 1941/42 .50 cal ammo. The "ball" ammo was slightly heavier but around 300fps slower in velocity.
same for the AP, a change in the propellent allowed for the higher velocity. There was no incendiary ammo in 1940. It was still in the experimental stage.

given these facts the British Decision to go with six guns is a lot more understandable and it has a lot less to do with different philosophies about air to air combat.

What kind of guns the Martlets were delivered with I don't know and if delivered with the slow firing guns how long it took for them to be upgraded I also don't know.
With the original guns and ammo load the four gun plane had over 43 seconds of firing time and the six gun plane would have had 24 seconds. The Hurricane/Spitfires had around 17-18 seconds. A Fulmar with 800rpg (?) was good for around 40 seconds.
Once the faster firing .50s showed up the firing times would drop to around 19 seconds for the six gun fighters and 34-35 seconds for the 4 gun fighters.

 

[Greyman]

A Fulmar with 800rpg (?)

750 rpg for the Mk.I

1,000 rpg for the Mk.II
370 rpg for the .50s

 

[Conslaw]

The British ordered the six gun Martlets in the summer of 1940, The FW 200 had gone into service in April of 1940 (6 of them) flying from Danish bases, By mid may only two were serviceable. The unit was withdrawn from action in June , requiped and sent to Bordeaux-Merignac in July.
There may be a little bit of cross over there but thinking that the Martlet (with 6 guns) was intended to be an anti Condor plane may be pushing things. The CAM ships don't show up until the Spring (May) of 1941 for example.

My own theory is that when the Martlets were ordered, the .50 cal Browning was still a 600rpm machine gun (at best). The British are used to eight guns firing 1100-1200rpm each although smaller bullets. At some point in 1940 the .50 cal Browning was improved to around 800 rpm so that four guns could deliver almost the same firepower as six of the original guns. The US Navy never used the slower firing guns in combat ( the existing guns could be modified with a parts kit).

I have also repeated (many times) the fact that 1940 .50 cal ammo was NOT the same as 1941/42 .50 cal ammo. The "ball" ammo was slightly heavier but around 300fps slower in velocity.
same for the AP, a change in the propellent allowed for the higher velocity. There was no incendiary ammo in 1940. It was still in the experimental stage.

given these facts the British Decision to go with six guns is a lot more understandable and it has a lot less to do with different philosophies about air to air combat.

What kind of guns the Martlets were delivered with I don't know and if delivered with the slow firing guns how long it took for them to be upgraded I also don't know.
With the original guns and ammo load the four gun plane had over 43 seconds of firing time and the six gun plane would have had 24 seconds. The Hurricane/Spitfires had around 17-18 seconds. A Fulmar with 800rpg (?) was good for around 40 seconds.
Once the faster firing .50s showed up the firing times would drop to around 19 seconds for the six gun fighters and 34-35 seconds for the 4 gun fighters.

When did the changeover from the F4F-3 to F4F-4 occur on the production line?

 

[tomo pauk]

When did the changeover from the F4F-3 to F4F-4 occur on the production line?

1st F4F-4 was delivered in December 1941. Looking at numbers produced of the F4F-3, my take is that change was over some time in February of 1942.

 

[Shortround6]

Things may have overlapped a bit.
The Martlet IIs (the last 90 out of 100 got folding wings) used two speed engines instead of two stage and engine wise, were equivalent to the F4F-3A.
There were 65 F4F-3As built during 1941 to December of 1941 with fixed wings and two speed engines. Most went to the Marines (not good enough for the Navy? give it to the Marines

Some parts have to be ordered months before the plane is assembled, just because they test flew a folding WIldcat in May of 1941 doesn't mean the production line could switch over.

 

[Conslaw]

IIRC from Lundstrum, The Hornet and Enterprise got their F4F-4s after they got back to Pearl Harbor from the Doolittle raid. The Lexington and Yorktown fought the Battle of the Coral Sea with F4F-3s, and when the Yorktown made it back to Pearl Harbor it exchanged its fighter squadron with VF-3 from the Saratoga, which already had F4F-4s. (The Saratoga at this time had been torpedoed by a submarine and sailed to the mainland for repairs, returning just too late for the Midway battle. )

 

[R Leonard]

Preface by saying the below ignores the existence of the XF4F-4 which was delivered in April 1941 and addresses strictly the initial F4F-4 production.

The September 1941 BuAer Monthly Status of Aircraft report notes in the section regarding status of aircraft under construction:

F4F-3 #'s 3856-3874; 3970-4057
Contract # 75736, 5 Aug 1940; 107 Ordered, 107 Delivered; further noted as "All delivered"

F4F-4 #s 4058-4098; 5030-5262; 01991-02152; 03385-03544
Contract # 75736, 5 Aug 1940
Number Ordered: 596
Number Delivered: 0
Delivery Schedule: 10 in Oct. 1941; 15 in Nov.; 16 in Dec.; then 30 per month through Aug. 1942; 40 in Sept.; then 45 per month until completion of the contract.

The October 1941 Monthly Status of Aircraft notes in its Grumman recap:
"Delays in production of the F4F-4 airplanes have been occasioned by difficulty in obtaining wing hinge fittings for the folding-wing airplanes. Delay has been caused by a shortage of machine tools to complete processing in the plant of a subcontractor (City Machine and Tool Company of Toledo, Ohio). Allocation of the limited production of folding wing fighters scheduled for October, November, and early December, has been made to the British. Deliveries of fighters to the Navy cannot be expected until December. Production of fixed wing fighters in the interim could not be continued due to the fact that jigs and fixtures had already been converted to the folding-wing type. The bureau has approved further plant expansion for Grumman which will lead to eventual output of approximately 75 fighters per month in the spring of 1942. Plans for production of the F6F's are being actively prosecuted."

From this I'm led to believe that by the end of September 1941 production of the F4F-3 had ceased vice the F4F-4. Note the wording above regarding the initial production going to the British.

In fact, there were 36 G-36B (FAA F4F-4's, folding wings, six guns) that were delivered in October 1941 to the British Purchasing Commission (BPC) in New York; they were shipped from Norfolk NOB aboard HMS Illustrious departing on 12 December 1941. An additional 54 G-36B were delivered in December 1941 to BPC in New York and were shipped in March 1942, though I am uncertain as to by what conveyance. Be that as it may, by the end of December 1941, 90 G-36B/F4F-4 types had come off the line and been delivered, just not to the USN. These 90 G-36B/F4F-4 types were from ordered through contract #127 between BPC and Grumman which called for 100 aircraft. The first 10 aircraft under the contract were G-36A/F4F-3 types, delivered to BPC in March 1941. It was after these were delivered that BPC filed a change order amending the specifications to folding wings and 6 guns.

Production reported in the October report shows no F4F-3 deliveries and notes the following production schedule for F4F-4's:

F4F-4 #s 4058-4098; 5030-5262; 01991-02152; 03385-03544
Contract # 75736, 5 Aug 1940
Number Ordered: 596
Number Delivered: 0
Delivery Schedule: 1 in Nov. 1941; 11 in Dec.; 40 in Jan. 1942; 50 in Feb; 40 in Mar; 40 in Apr; 40 in May; 40 in June; 47 in July; 45 in Aug; 45 in Sep.; 37 in Oct.; 36 in Nov.; 50 in Dec.; 45 in Jan. 1943; 29 in Feb.

The November Monthly Status report also offers a small gem . . . on the second page, showing "Status of Procurement Program," there is a line under 1941 which shows the F4F-3-4 with programmed as 659 and delivered as 203. Noted is that included under F4F-3-4 programmed are 21 F4F-7's, not noted as delivered. Under the 1942 heading there appears the F4F-4 with programmed as 160 and delivered as 0. Some quick math gives us 659+160 = 819, less 203 = 616, less 21 = 595. Hmmm, but the contract for the F4F-4 calls for 596 . . . we seem to be short one.

Ah, but when arriving on page 6 all is right in the world, for in the Aircraft Under Construction section, for the F4F-4 (and there is, again, no listing for the F4F-3), the report shows:

F4F-4 #s 4058-4098; 5030-5262; 01991-02152; 03385-03544
Contract # 75736, 5 Aug 1940
Number Ordered: 596
Number Delivered: 1
Delivery Schedule: 10 in Dec.; 49 in Jan. 1942; 38 in Feb; 40 in Mar; 50 in Apr; 50 in May; 36 in June; 44 in July; 50 in Aug; 50 in Sep.; 50 in Oct.; 50 in Nov.; 50 in Dec.; 28 in Jan. 1943.

This same portion of the monthly report also confirms that none of the 21 programmed F4F-7's had yet been delivered.

So, the first F4F-4 delivered to the USN was in November 1941, just one, but after 90 had been delivered to BPC for transfer to the Royal Navy.

And lastly, the December 1941 BuAer Monthly Status of Aircraft reports:
F4F-4 #s 4058-4098; 5030-5262; 01991-02152; 03385-03544
Contract # 75736, 5 Aug 1940
Number Ordered: 596
Number Delivered: 5
Delivery Schedule: 38 in Feb; 40 in Mar; 50 in Apr; 50 in May; 36 in June; 44 in July; 50 in Aug; 50 in Sept; 50 in Oct; 50 Nov; 50 in Dec; 28 in Jan 1943.

The report also notes in the recap section under Grumman:
"The Navy received a total of four (4) F4F-4 airplanes during the month of December and Grumman estimates he will deliver 60 of the F4F-4's in January. From now on to completion of the F4F-4 contracts barring shortages of materials the F4F-4 airplanes should be delivered to service activities at least equal to, and probably higher than, their scheduled rate of 50/mo. The shortages of folding wing fittings have been eliminated and the propeller situation now appears to be well in hand with Curtiss giving every indication of being able to meet Grumman deliveries plus reasonable spares."

Safe to presume that production of the F4F-3 ended in late September 1941 and production shifted to the F4F-4.

R

 

[nuuumannn]

From the British perspective in ordering the 6-gun Marlet (what would become the F4F-4), they were looking at encounters with slingle FW Condors and U-Boats, primarily.

The 6-gun Martlett was the Mk.II, which was based on the F4F-3; the first F4F-4s in RN service were Mk.IIIs and then the F4F-4B on Lend Lease were Martlett IVs.

There may be a little bit of cross over there but thinking that the Martlet (with 6 guns) was intended to be an anti Condor plane may be pushing things.

Yup. The Martlett was ordered by the FAA because of the Air Ministry's refusal to get Supermarine to build the navy a 'Sea Spitfire', which was going to divert from supply of the Spitty to the RAF. The Martlett (and indeed the Sea Hurricane) as a naval single seater was an interim until the arrival of the Blackburn Firebrand, which the Admiralty hoped was to be the next naval single-seater.

 

[Kevin J]

The 6-gun Martlett was the Mk.II, which was based on the F4F-3; the first F4F-4s in RN service were Mk.IIIs and then the F4F-4B on Lend Lease were Martlett IVs.



Yup. The Martlett was ordered by the FAA because of the Air Ministry's refusal to get Supermarine to build the navy a 'Sea Spitfire', which was going to divert from supply of the Spitty to the RAF. The Martlett (and indeed the Sea Hurricane) as a naval single seater was an interim until the arrival of the Blackburn Firebrand, which the Admiralty hoped was to be the next naval single-seater.

Hmm, and I thought we got the Firefly because Fairey proposed it as a better alternative to building a Sea Spitfire. Just a reminder of statistics. Take a Spitfire I/II, add catapult spools, arrestor hook and folding wings, take off 20 mph, and what you get is a fighter with the same speed as a Wildcat. I think I'd prefer a Wildcat.

 

[nuuumannn]

Hmm, and I thought we got the Firefly because Fairey proposed it as a better alternative to building a Sea Spitfire.

The first Martletts the FAA received were diverted from a French order that went unfulfilled due to obvious reasons, but were supplimented by Martlett IIs with folding wings and improved armament.

The Firefly was built to a multi-seat specification borne out of two different specs that were canned for various reasons, as a follow on from the Fulmar. The Air Ministry (not the Admiralty) was keen on two-seaters for the navy, the reason given was that performance wise (in their minds) there wasn't much of a difference between them (a bit of an underestimation, but there you go) but simultaneously the Admiralty wanted a single seater; specifically Sea Spitfires, but had a number of single-seat designs underway at the time, which doesn't lend too much credence to the fact that it had forgotten about single seaters, its just none of them worked out as they had intended.

The logic behind the two-seaters was spelled out as being a different requirement for a fighter than that of the RAF. The FAA, it was argued wanted a fighter that could intercept long range bombers bent on attacking the fleet, therefore they would have been of large-ish size and range to reach ships at sea, whereas the RAF required interceptors for attacking a variety of bombers with differing performance, not to mention escort fighters. The naval fighter also needed long range, too. Performance difference was not predicted as being as important against such a bomber seeking ships at sea. At the early stage of the war, when the Firefly's spec was released, February 1940, it was argued that the navy fighters would not encounter single-seaters, so two-seaters were acceptable.

But, like I said, the Admiralty wanted single seaters for its carriers as it was felt they might be needed at certain times (!), and so, simultaneously, the Firebrand spec was drawn up and released later in the year, but had its origins in the two earlier specs that were initially issued before the Firefly but canned; N.8/39 and N.9/39.

 

[nuuumannn]

Take a Spitfire I/II, add catapult spools, arrestor hook and folding wings, take off 20 mph, and what you get is a fighter with the same speed as a Wildcat.

That's why you wait until Rolls has produced the Merlin 45 with improved supercharger, which came in late 1940/early 1941, or better still, as it transpired, wait for the two-speed, two-stage 60 Series Merlin or indeed the Griffon for even greater performance leaps.

 

[Clayton Magnet]

Take a Spitfire I/II, add catapult spools, arrestor hook and folding wings, take off 20 mph, and what you get is a fighter with the same speed as a Wildcat. I think I'd prefer a Wildcat.

Correct me if I am wrong, but a navalized Spitfire I/II would have been available in 1940, if the Air Ministry would have allowed it. Which would have made it a contemporary of the F3F, not the Wildcat. I think I would prefer a Seafire.

 

[Kevin J]

Correct me if I am wrong, but a navalized Spitfire I/II would have been available in 1940, if the Air Ministry would have allowed it. Which would have made it a contemporary of the F3F, not the Wildcat. I think I would prefer a Seafire.

I don't know about the US, but we had shore based Martlet I's operational in late 1940 scoring their first victory on Christmas Day.

 

[Clayton Magnet]

I think the first shipbourne Martlets went to sea in the summer on 1941, but I believe you are correct, the first kill was in December of 1940. The Admiralty had first requested navalized Spitfires in May of 1938, so perhaps they could have been available earlier than 1940, had the air ministry approved it.

 

[Kevin J]

I think the first shipbourne Martlets went to sea in the summer on 1941, but I believe you are correct, the first kill was in December of 1940. The Admiralty had first requested navalized Spitfires in May of 1938, so perhaps they could have been available earlier than 1940, had the air ministry approved it.

Supermarine had only completed 46 by the beginning of 1939, 306 of their first order of 310 in September 1939. From first flight of a Seafire Ib to introduction of the Seafire FIII was two years. From first flight to service deliveries of the IB/IIC was over six months, or 12 months to service intro. The only way you're going to get a Seafire into service in 1939 is if you cancel Spitfire in favour of Seafire production. Its only when Westland production starts in 1941 that you have spare planes that can be Seafires, unless of course you want to lose the BoB by only operating Hurricanes.

 

[Clayton Magnet]

I thought Fairey proposed a navalized Spitfire, only to be told to forget it, and concentrate on Fulmar production? I wonder what kind of agreement existed between Fairey and Supermarine for that kind of proposal to be possible

Getting off topic, my apologies

 

[Kevin J]

I thought Fairey proposed a navalized Spitfire, only to be told to forget it, and concentrate on Fulmar production? I wonder what kind of agreement existed between Fairey and Supermarine for that kind of proposal to be possible

Getting off topic, my apologies

IIRC Fairey was asked to produce the folding wing Spitfire and came back with a better design, the Firefly. Unfortunately, its engine development got delayed in 1940 because of the 'imminent invasion' crisis.

 

[nuuumannn]

IIRC Fairey was asked to produce the folding wing Spitfire and came back with a better design, the Firefly.

Well, yes and no. Yes, Richard Fairey himself was asked to build folding wing Spitfires at a meeting held at the Admiralty in 1938, but he initially refused, stating that the Swordfish and Fulmar production would be stymied as a result; he also believed the Spitfire wouldn't be much better than the Fulmar as a fighter - 300 Spitfires wouldn't be worth sacrificing 200 Fulmars for in production terms, in his opinion. He was even given a veiled threat by those in attendance regarding his factories!

Joe Smith had drawn up folding wings on the Spitty by late 1939 in anticipation of an order from the Admiralty, with the support of Director of Technical Development Verney, who had written to Smith proposing the naval Spitfire previously, but oddly, it was Churchill as First Lord of the Admiralty who stopped the first iteration of the Sea Spitfire, stating to Beaverbrook that he wanted Fulmar production to be kept up, not to mention deliveries of the Spitfire to the RAF that would be interrupted if the Supermarine built the Sea Spitfire, but that wasn't up to Churchill in late 1939.

The Firefly, as I stated earlier was built to spec N.5/40 that was the successor to N.8/39 and N.9/39, to which Supermarine had proposed separate entries for, loosely based on the Spitfire; these were for two-seaters, not single-seaters, one of which was for a turret fighter.

 

[ThomasP]

I have read that Hawker, in 1938, did a study on a folding wing Hurricane for carrier duty but were turned down when it was offered to the Admiralty. I have never run across the reason why they were turned down. I have always assumed that it was due to the need for a 2-man crew (for navigation purposes) being more important at that time, along with a limited value placed on single purpose aircraft. The folding wing and suitable navalization would have added a few hundred pounds to the Hurricane but the result would still have been faster than the Fulmar.