WW2 with no Spitfire - Hurricane being primary interceptor

[RCAFson]

What about the Spitfire? well, thats a tough one for me because of my commonwealth and British biases. I cant be as hard on the Spit because of that. But I think I would have to say that Spit had faults of its own. I think they were different though to the hellcats. I think the Spitfire was absolutely necessary to the allies through to 1942, in the same way as the Mustang was from 1944. The allies needed the Spitfire in the early stages to survive. in a defensive war, fighters assume greater importance for obvious reasons, and in reality there was nothing available that could quite do what the Spit was able to do. certainly not the hurricane.

My own feeling is that if the money spent on Spitfire development (and procurement)was instead used to boost Hurricane development and production, that initially, up to about mid 1941, that the net result would have been positive, as more Hurricanes (3 Hurricanes for every two historical Spitfires plus historical Hurricane production), with better access to Merlin engine development (Merlin 12, 45), in a cleaned up Hurricane airframe would have resulted in a stronger RAF. However, once the 109F and FW190 arrive in numbers the situation gets a lot more difficult for Hurricanes unless it can accept a wing change. However even the existing design with modest changes might be able to hold the line until newer designs arrive in numbers.

 

[wuzak]

While the Spitfire got the Merlin 45 the Hurricane got the Merlin XX - the 45 using essentially the same supercharger as the XX but with only the one speed.

The Spitfire III was to get the Merlin XX, but these were deemed necessary for the Hurricane. From what I understand the Spitfire III with Merlin XX would have had less of a difficult time against the Fw 190 than the Spitfire V with the Merlin 45.

And when it comes to development, when the Hurricane needs a new wing and there has to be a change-over any production advantages seen previously will be lost.

Also, I don't think the Hurricane fared particularly well against the Bf 109E, and even less so against the Bf 109F.

Any development resources spent on teh Hurricane also detracts from the efforts with the Typhoon.

 

[RCAFson]

While the Spitfire got the Merlin 45 the Hurricane got the Merlin XX - the 45 using essentially the same supercharger as the XX but with only the one speed.

The Spitfire III was to get the Merlin XX, but these were deemed necessary for the Hurricane. From what I understand the Spitfire III with Merlin XX would have had less of a difficult time against the Fw 190 than the Spitfire V with the Merlin 45.

And when it comes to development, when the Hurricane needs a new wing and there has to be a change-over any production advantages seen previously will be lost.

Also, I don't think the Hurricane fared particularly well against the Bf 109E, and even less so against the Bf 109F.

Any development resources spent on teh Hurricane also detracts from the efforts with the Typhoon.

My point is that the Hurricane would receive both the Merlin 12/45 and XX so that the average Hurricane would receive an upgraded engine (over the Merlin III) sooner than historically.

The Spitfire III airframe was also a factor in it's improved performance, and a Spit III would with Merlin 45 would have outperformed the Spit V.

I don't agree that a wing change would negate any production advantage because the Hurricane was easier to build, and would have been built in multiple facilities (as per the Hurricane and Spitfire in the OTL), so the change could me made in stages until all factories changed over to the new wing design.

The Hurricane might do worse than the Spitfire against the Me109e, but then there are more of them, and they will perform better than the historical Hurricane because they will, on average, have better engines.

The design team that worked on the Spitfire, historically, would be freed to advance other design, including, for example, the Typhoon.

 

[Aozora]

"Newer designs" which could have taken over from the modified Hurricane; Typhoon: Mustang I converted to take Merlin 60 series: Martin-Baker MB2. The design cupboard was pretty bare...

 

[parsifal]

oh am i gonna regret saying that.....

interesting topic though dont you agree

This gets back to the same basic Sh*t fight that the Hellcat/Spit argument was about. Throw enough money at something and you will get a solution....problem is is it worth it. How much money was spent on getting the Spit to its 1939-40 state of performance? Would a similar amount of money achieve sufficient performance from the hurricane airframe.

There is an advantage worth noting in having just one airframe to do the job of two.....savings in logistics, spare parts, comonality for training etc. So, having one type instead of two gives certain advantages of itself.

I am doubtful about the Hurricane being able to pull it off. Unlike the Wildcat discussion, Hurricane was approaching obsolescence in 1939. It was old technoilogy in terms of the airframe and its performance was starting to suffer compared to its main opposition. not so for the Wildcat.

But improvements in the Hurricane may have stretched things long enough to make the spit unnecessary.....but at what cost, and could it be done in time?

That rather than the performance issue is the critical question

 

[wuzak]

My point is that the Hurricane would receive both the Merlin 12/45 and XX so that the average Hurricane would receive an upgraded engine (over the Merlin III) sooner than historically.

I doubt that the Hurricane would get the Merlin 45 if they get the XX.

The Spitfire III airframe was also a factor in it's improved performance, and a Spit III would with Merlin 45 would have outperformed the Spit V.

That may be so, but the Merlin XX Spitfire III would outperform a Merlin 45 Spitfire III. And the same if the XX was put into the Spitfire V.

The extra gear means that the performance down low is better, while maintaining the altitude performance.

I don't agree that a wing change would negate any production advantage because the Hurricane was easier to build, and would have been built in multiple facilities (as per the Hurricane and Spitfire in the OTL), so the change could me made in stages until all factories changed over to the new wing design.

The Spitfire was built in multiple factories, but how long did it take to get the new wing into production (for the Spit 21)?

The Hurricane might do worse than the Spitfire against the Me109e, but then there are more of them, and they will perform better than the historical Hurricane because they will, on average, have better engines.

But the performance improvement won't get the Hurricane anywhere near the Spitfire's performance on the same engine.

The design team that worked on the Spitfire, historically, would be freed to advance other design, including, for example, the Typhoon.

Historically it was the Hurricane's design team who were freed up to work on the Typhoon. It must be remembered that the Typhoon was intended to replace both the Hurricane and the Spitfire, but was unable to replace the latter.

 

[wuzak]

My own feeling is that if the money spent on Spitfire development (and procurement)was instead used to boost Hurricane development and production, that initially, up to about mid 1941, that the net result would have been positive, as more Hurricanes (3 Hurricanes for every two historical Spitfires plus historical Hurricane production), with better access to Merlin engine development (Merlin 12, 45), in a cleaned up Hurricane airframe would have resulted in a stronger RAF.

I feel that had they given the choice to swap Hurricanes for Spitfires in that ratio (ie 2 Spitfires for 3 Hurricanes) prior to the BoB the RAF would have jumped at the chance.

 

[stug3]

If there had been no Spit, they would have relied on the P-40 even more and the Mustang would have been the answer to their prayers, especially once they figured they should stick a Merlin in it.

 

[RCAFson]

I doubt that the Hurricane would get the Merlin 45 if they get the XX.

The 12/45 would give the Hurricane a big boost in performance over the Merlin III and it's cheaper and lighter than the XX, so why wouldn't they use it in the Hurricane? The Sea Hurricane, in particular would have greatly benefited from the Merlin 45, especially when 16lb boost comes along and for that matter, the Fulmar as well.

That may be so, but the Merlin XX Spitfire III would outperform a Merlin 45 Spitfire III. And the same if the XX was put into the Spitfire V.

The extra gear means that the performance down low is better, while maintaining the altitude performance.

Actually, at high altitude the 45/46 should be better since it is lighter and provides the same boost levels. In any event if we compare a Spitfire Va to a Hurricane IIa, the variation in performance is not that great with the Va giving about 375 mph versus 342 for the IIa, and loaded to the same degree, the Vc (4 cannon) is only about 20-25mph faster than the IIC with 4 cannon.

The Spitfire was built in multiple factories, but how long did it take to get the new wing into production (for the Spit 21)?

That's a very dissimilar situation, as the original Spitfire wing was already very good, so no urgency to change.

But the performance improvement won't get the Hurricane anywhere near the Spitfire's performance on the same engine.

Clean up the Hurricane airframe, give it a retractable tail wheel, and lighter armament (as per the Spitfire) and Merlin 60 series and I'll bet that the difference is not that great.

Historically it was the Hurricane's design team who were freed up to work on the Typhoon. It must be remembered that the Typhoon was intended to replace both the Hurricane and the Spitfire, but was unable to replace the latter.

It would be interesting to know what a wing change could have done for the Hurricane.

 

[davebender]

Most of the Lufwaffe deployed east during mid 1941. No Spitfires might put a crimp in RAF Circus raids during 1941 to 1942 but otherwise it hardly matters.

July 1943 is a different story. What replaces the horde of Spitfires on Malta to cover the invasion of Sicily and southern Italy?

 

[RCAFson]

I feel that had they given the choice to swap Hurricanes for Spitfires in that ratio (ie 2 Spitfires for 3 Hurricanes) prior to the BoB the RAF would have jumped at the chance.

I'm pretty sure that they wouldn't do that. The Hurricane had better serviceability rates, was easier to repair, could operate from rougher airstrips, was much faster to build (2/3 of the man hours per aircraft). The Hurricane could shoot down a bomber or 109/110 just as well (or better because of better gun placement) as a Spitfire, and it could out-turn the Spitfire as well which was at least partial compensation for it's poorer high altitude performance. Hurricane/Spitfire loss rates during the BofB are skewed because the Hurricane was assigned primarily to 11 Group and so bore the brunt of the battle from forward airstrips where it was much more likely to be bounced than the predominately 12/13 Group Spitfires. Additionally when looking at Hurricane versus Spitfire stats during the BofB you must remember that the Spitfires got the Merlin 12 before the Hurricane got the Merlin XX and a Merlin 12 powered Hurricane would have performed better at high altitudes.

Hurricane/Spitfire squadron allocation by Group:

8 July 1940

10 group:

2 x H
2 x S

11 group

12 x H
6 x S

12 group

5 x S
5 x H

13 group

6 x S
3 x H

 

[RCAFson]

Most of the Lufwaffe deployed east during mid 1941. No Spitfires might put a crimp in RAF Circus raids during 1941 to 1942 but otherwise it hardly matters.

July 1943 is a different story. What replaces the horde of Spitfires on Malta to cover the invasion of Sicily and southern Italy?

Curtailing the Circus raids would have resulted in dramatically lower RAF pilot losses.

Malta in 1942 and 1943 is a interesting case. I would argue that a lightweight Hurricane (say 2 x 20mm and 4 x .303 or even 4 x .5in Vickers) along with a cleaned up airframe, could have provided some measure of protection from the 109f/190 but a new wing would probably have been needed to stay competitive.

 

[Aozora]

All this is assuming that Hawker would have bothered going to the time and expense of significantly modifying an already obsolescent design, when all their time and effort was devoted to the Tornado/Typhoon? Then it makes the assumption that Sydney Camm would have realised earlier than he did that the thick wing was inhibiting fighter performance.

It is also assuming that designing a new wing and adding it to an obsolescent design could be done quickly and easily, or be worth doing at all. Why not put the new thin wing design on a lightweight Typhoon armed with, say, 4x.303x and two 20mm Hispanos and replace the Sabre with a Merlin 61 or Griffon?

Why not put all the time and effort devoted to the obsolescent Hurricane into developing a lightweight, single-seat version of the defiant, as was mooted in 1940?

 

[Shortround6]

The 12/45 would give the Hurricane a big boost in performance over the Merlin III and it's cheaper and lighter than the XX, so why wouldn't they use it in the Hurricane? The Sea Hurricane, in particular would have greatly benefited from the Merlin 45, especially when 16lb boost comes along and for that matter, the Fulmar as well.

The Merlin 45 is basically a Merlin XX with low gear to the supercharger left out. A bit cheaper yes. lighter by 65lbs? the Sea Hurricane would have been dismal with a Merlin 45. take off power for a Merlin 45 was 1185hp at 12lbs of boost. Merlin XX gave 1280hp at 12lb boost for take-off. Cutting 100hp from your power for a carrier take-off doesn't sound like a good idea. Throw in the fact that you loose a bit of power at higher altitudes and it really doesn't sound like a good idea. 1515hp at 11,000ft with 16lbs of boost for the Merlin 45 vs 1490hp at 12,500ft at 16lb boost for the Merlin XX.
Merlin XX engines started to be but into Hurricanes during the BoB.

Actually, at high altitude the 45/46 should be better since it is lighter and provides the same boost levels. In any event if we compare a Spitfire Va to a Hurricane IIa, the variation in performance is not that great with the Va giving about 375 mph versus 342 for the IIa, and loaded to the same degree, the Vc (4 cannon) is only about 20-25mph faster than the IIC with 4 cannon.

Again it is only 65lbs lighter and it does NOT provide the same power levels either down low or up high. Merlin 45 used a 9.089 supercharger gear, the Merlin XX used a 8.15 low gear meaning less power used to drive the supercharge at low altitude to get the same boost and less heating of the intake charge. It also used a 9.49 high gear that took a bit more power than the Merlin 45 but meant the same boost could be held to a higher altitude.

Clean up the Hurricane airframe, give it a retractable tail wheel, and lighter armament (as per the Spitfire) and Merlin 60 series and I'll bet that the difference is not that great.

I guess a lot depends on your idea of "Clean up the Hurricane airframe". Seeing as how the basic Hurricane I was about 40mph slower than a Spitfire I using the same engine and prop.

Designing a new airplane and just calling it a Hurricane could do wonders for improving the performance.

 

[RCAFson]

All this is assuming
Why not put all the time and effort devoted to the obsolescent Hurricane into developing a lightweight, single-seat version of the defiant, as was mooted in 1940?

Because it is cheap and easy to build and well suited to the Merlin, which is also cheap, reliable and easy to build.

 

[wuzak]

The 12/45 would give the Hurricane a big boost in performance over the Merlin III and it's cheaper and lighter than the XX, so why wouldn't they use it in the Hurricane? The Sea Hurricane, in particular would have greatly benefited from the Merlin 45, especially when 16lb boost comes along and for that matter, the Fulmar as well.

The Merlin XX would still give better overall performance.

The XX was about 50-75lbs heavier than the 45. So not that much really.

Cheaper to build - yes. I can't quantify that, though.

Actually, at high altitude the 45/46 should be better since it is lighter and provides the same boost levels. In any event if we compare a Spitfire Va to a Hurricane IIa, the variation in performance is not that great with the Va giving about 375 mph versus 342 for the IIa, and loaded to the same degree, the Vc (4 cannon) is only about 20-25mph faster than the IIC with 4 cannon.

The Hurricane II used the Merlin XX.

The reports at Hurricane Mk II Performance give the IIC at no more than 330mph maximum.

This chart shows that the speed isn't improved with increased boost.

http://www.wwiiaircraftperformance.org/hurricane/hurricane-IIc-raechart-level.jpg

That's a very dissimilar situation, as the original Spitfire wing was already very good, so no urgency to change.

There were issues with the Spitfire wing, and there was the desire to improve the rolling characteristics.

Clean up the Hurricane airframe, give it a retractable tail wheel, and lighter armament (as per the Spitfire) and Merlin 60 series and I'll bet that the difference is not that great.

Lighter armament? Much the same weren't they?

Clean up the Hurricane airframe,

It would be interesting to know what a wing change could have done for the Hurricane.

May as well have built a new design.

 

[wuzak]

Because it is cheap and easy to build and well suited to the Merlin, which is also cheap, reliable and easy to build.

So, why not the Miles M20?

 

[RCAFson]

The Merlin 45 is basically a Merlin XX with low gear to the supercharger left out. A bit cheaper yes. lighter by 65lbs? the Sea Hurricane would have been dismal with a Merlin 45. take off power for a Merlin 45 was 1185hp at 12lbs of boost. Merlin XX gave 1280hp at 12lb boost for take-off. Cutting 100hp from your power for a carrier take-off doesn't sound like a good idea. Throw in the fact that you loose a bit of power at higher altitudes and it really doesn't sound like a good idea. 1515hp at 11,000ft with 16lbs of boost for the Merlin 45 vs 1490hp at 12,500ft at 16lb boost for the Merlin XX.
Merlin XX engines started to be but into Hurricanes during the BoB.

All Sea Hurricanes used during Harpoon and Pedestal used Merlin IIIs, so the Merlin 12/45 would have been a considerable improvement.

Again it is only 65lbs lighter and it does NOT provide the same power levels either down low or up high. Merlin 45 used a 9.089 supercharger gear, the Merlin XX used a 8.15 low gear meaning less power used to drive the supercharge at low altitude to get the same boost and less heating of the intake charge. It also used a 9.49 high gear that took a bit more power than the Merlin 45 but meant the same boost could be held to a higher altitude.

The Hurricane IIa weighs about 200lb more than the Ia, so somewhere there's a lot more weight to the XX installation. Your own numbers:
1515hp at 11,000ft with 16lbs of boost for the Merlin 45 vs 1490hp at 12,500ft at 16lb boost for the Merlin XX suggest that the Merlin 45 is more efficient at medium altitude at the same boost, but again the point isn't that the 12/45 is better than the XX, but that it is better than the III, and that the Hurricane could be fitted with whichever engine is best suited for a particular role.

I guess a lot depends on your idea of "Clean up the Hurricane airframe". Seeing as how the basic Hurricane I was about 40mph slower than a Spitfire I using the same engine and prop.

That's debatable. Low altitude performance of the Hurricane Spitfire with a Merlin 45 and at 16lb boost would differ by about 20-30 mph; certainly the Spitfire is faster but then there's going to be a lot more Hurricanes.

Designing a new airplane and just calling it a Hurricane could do wonders for improving the performance.

Hurricane airframe design (for improved performance) was basically stopped in early 1940, yet most of it's contemporaries continued development for several years after that date - which doesn't seem to raise any eyebrows.

 

[wuzak]

Hurricane airframe design (for improved performance) was basically stopped in early 1940, yet most of it's contemporaries continued development for several years after that date - which doesn't seem to raise any eyebrows.

To me the Hurricane looks like a bi-plane fighter modified as a monoplane fighter.

 

[Jabberwocky]

To me the Hurricane looks like a bi-plane fighter modified as a monoplane fighter.

Because that's what it was. The design was based on Camm's 1933 re-work of the Fury biplane.