Hurricane evolution

[HoHun]

Hi Michael,

>what do those great graphs mean HoHun?

In response to your PM, one could say they don't really "mean" anything by themselves. They're like a dinosaur footprint ... you learn something about the size, the weight, the speed and the build of the dinosaur from this print, but does the footprint actually "mean" anything? Not without some knowledge of the context ... what where its enemies or its competitors, how did the terrain look back when the dinosaur crossed it, what was its natural habitat, and so on.

I am aware these diagrams are not self-explanatory to everyone, so I wasn't sure if you were asking how to read them or if you asked for their impact on the issue of Hurricane evolution - both perfectly legitimate questions in my opinion!

Regards,

Henning (HoHun)

 

[michaelmaltby]

Thank you, Henning. I grasp your description of "mean" as in animal prints. I assume by plotting similar graphs for different ac one would see at-a-glance where that ac's optimal characteristics were.

Every design is a compromise - in quest of a competitive advantage, n'est-ce pas?

Chairs,

Michael

 

[HoHun]

Hi Michael,

>I assume by plotting similar graphs for different ac one would see at-a-glance where that ac's optimal characteristics were.

Exactly! As the Hurricane's evolution tended more towards ground attack than towards air-to-air fighting, I didn't include enemy types in the Hurricane graphs above, but I have posted such graphs in various other threads in this forum, so examples of that kind might surface from time to time, too

Regards,

Henning (HoHun)

 

[michaelmaltby]

Late to the game:

Colin: "it wasn't a wooden wing during the Battle either, in fact, it was never a wooden wing. Fabric was employed until increased armament requirements prompted Hawker's engineers to re-appraise the situation with a design study for metal stressed-skin wings. They also realised that any damage to a fabric wing would likely lead to ballooning and the rest of the fabric being torn from the aircraft.."

I've also read that canon shells passed through the fabric and - if didn't hit anything vital - passed clean through without exploding.

MM

 

[Colin1]

I've also read that cannon shells passed through the fabric and - if didn't hit anything vital - passed clean through without exploding

Hi Michael
you may well have a point - if I was a Hurricane pilot, a chance I'd rather not take!

 

[michaelmaltby]

Agreed ..

 

[slaterat]

In reality the British Air Ministry was not interested in improving the Hurricane and held back the development of the Hurricane. Francis K Mason's book "The Hawker Hurricane " details some of Hawkers proposals that were declined.

1936 proposal for a 4 20mm cannon armed Hurricane declined
1940-41 proposal for a Griffon engined Hurricane declined
1942 proposal for an improved canopy and reduced aft fuselage declined

The Air Ministry greatly hampered the introduction of metal covered wings on the Hurricane too.

I suppose The Air Ministry was counting on the Typhoon to step up to the plate in 41 and 42, which it failed to do being striken with a complex and unreliable engine and a semi monocoque tail assembly that had a disturbing tendency to fall off in high speed dives. Thus the poor old Hurricane had to serve the rest of the war on the frontline with an engine and airframe unmodified from 1940.

Slaterat

 

[Waynos]

The 1936 proposal for four 20mm cannon was in response to an air ministry requirement for a cannon fighter, not just an attempt to improve the Hurricane. The Whirlwind was selected for this order, Supermarine proposed a version of the Spitfire for this requirement too.

 

[Clay_Allison]

In reality the British Air Ministry was not interested in improving the Hurricane and held back the development of the Hurricane. Francis K Mason's book "The Hawker Hurricane " details some of Hawkers proposals that were declined.

1936 proposal for a 4 20mm cannon armed Hurricane declined
1940-41 proposal for a Griffon engined Hurricane declined
1942 proposal for an improved canopy and reduced aft fuselage declined

The Air Ministry greatly hampered the introduction of metal covered wings on the Hurricane too.

I suppose The Air Ministry was counting on the Typhoon to step up to the plate in 41 and 42, which it failed to do being striken with a complex and unreliable engine and a semi monocoque tail assembly that had a disturbing tendency to fall off in high speed dives. Thus the poor old Hurricane had to serve the rest of the war on the frontline with an engine and airframe unmodified from 1940.

Slaterat

A Griffon Engined Hurricane? Holy crap! That would be awesome!

 

[Jerry W. Loper]

Every time I see HoHuns graphs I really enjoy them. Thanks

As for Hurricane having fatal flaw, for me it's the tick wing. So despite receiving stronger engines, the plane just stucked around 550 km/h even with 1500HP (give or take).
As for the RP's, this is from Wiki (for what is worth ):

I knew that one of the Hurricane's weaknesses was its speed. Do you know what was the most powerful engine that was put in both a Hurricane and Spitfire, what was the Mark of each plane, and the top speed of each plane of that Mark, with that powerplant?

 

[tomo pauk]

A quick Google/Wiki combo yields this:

Hurricane Mk IV
The last major change to the Hurricane was to "rationalise" the wing, configuring it with a single design able to mount two bombs, two 40 mm Vickers S guns, or eight "60 pounder" RP-3 rockets. The new design also incorporated the improved Merlin 24 or 27 engines of 1,620 hp (1,208 kW), equipped with dust filters for desert operations.

If Im nort mistaken it, the top speed was just under 560km/h for Hurri IV.

Since it seems that no Spits received such an engine, the comparable engines could be the 60 series, with 1650+HP. The Spit MkIX could do circa 650km/h. So, the difference is a big one.

 

[Jerry W. Loper]

A quick Google/Wiki combo yields this:



If Im nort mistaken it, the top speed was just under 560km/h for Hurri IV.

Since it seems that no Spits received such an engine, the comparable engines could be the 60 series, with 1650+HP. The Spit MkIX could do circa 650km/h. So, the difference is a big one.

Thanks!

 

[Rocketeer]

Coming in late to this discussion of the lovely and great Hurricane.....the Hurri was a good evolution of an existing design...it was originally called the Fury monoplane.
Aircraft procurement went the same way.....Air Ministry propose a spec for a new aircraft requirement, manufacturers propose solutions, AM proceed with a couple for a fly off. The Hurricane was a proven design, excellent design platform (for stable weapon firing) and met its specs. The Spitfire came from a company that had little experience of fighters (granted Seaplane racing design). When VS got the go ahead into production they had to start from scratch on modern assembly techniques and processes. Odd to believe now that a Hurri was easier and cheaper to build than a spit then, but Hawkers had tried and tested processes and a ready made line/tooling.
Someone suggested earlier that money should have been spent getting Spits produced sooner as it was better.....given the job that would have entailed and the state of VS, its workforce....if that road had been gone down I would not be sat here typing this out!!!

A greater man than I will ever be said GB needed the Spitfire, but it had to have the Hurricane....In the dark days of 1940, Hurris could be repaired and mix'n'matched easily by civillian repair units.....repairing spits was more difficult.
Regarding evolution of the Hurricane design, it would have been interesting fitting a two stage two speed supercharged version of the Merlin (like the MkIX spit had)....it would have improved high altitude performance...

The thick wing was useful in that it allowed a more stable undercarriage arrangement than the spit.....and also the gun fit was easy to accommodate without the need for blisters!

The Typhoon was the natural successor...or should have been....the UK had a limited amount of production/development capability and this may have been part of the reason later Merlin marks and RR products were focussed on the spitfire developments and not things like Hurricanes...however, Napier could develop the unusually over complex H block Sabre for Tyffies/Tempests.....a bit like Lancs tended to have the monopoly on Merlins with Halifaxes having Hercules (though some aircraft were cross engine pollinated).....anyhoo I am probably boring you all now....sorry!

 

[tomo pauk]

No worries, Rocketeer

Just something re. engine development: instead of going Napier's way, the Brits should've press on for Hercules and Centaurus to be developed faster.

 

[Jabberwocky]

A quick Google/Wiki combo yields this:

If Im nort mistaken it, the top speed was just under 560km/h for Hurri IV.

Since it seems that no Spits received such an engine, the comparable engines could be the 60 series, with 1650+HP. The Spit MkIX could do circa 650km/h. So, the difference is a big one.

Not comparable engines though.

The low level dedicated single stage, two speed Merlin 24/27 in the Hurricane IV produced its peak power at about 9,000 feet

The high/medium altitude dedicated two stage two speed Merlin 61 or 66 fitted to the Spitfires produced their peak power at either 25,000 or 20,000 feet.

The fastest Hurricane was the Mk IIB, capable of about 540-560 kph on 1,280 hp (depends on what test and conditions).

Yes, the thick wing was a hinderance, but also a help. Its easier construction, strenght and modularity kept the Hurricance on the production line for at least an extra 18 months, to fulfil the role of fighter bomber.

 

[tomo pauk]

Hmm, then perhaps the Hurri with the 60´s series Merlin could do almost 580-600km/h @ 25kf (because of thin air there)...
Of course not a competitor for Spit IX.

I like the Hurri myself, seem a yeoman´s plane to boot with.

 

[Tartle]

Whilst researching the background of a Merlin XX that we run very occasionally it seems it may have been in a Hurricane at one point in its career... this little piece seems relevant to the thread...
In his book "Hurricane: Victor of the Battle of Britain" Leo McKinstry, writes on pages 228-230:
While the RAF struggled to find the ideal night-fighter [page 220: though the Hurricane was not designed for the role...it was felt that "The Hurricane is a simple aeroplane to fly by night. there is no glare in the cockpit, either open or closed, from the cockpit light or luminous instruments. The steady, steep glide at slow speed which is characteristic of this type makes landing extremely simple." But in practice the aeroplane proved woefully ineffective against German night intruders during the long winter of 1940-41.... by far the the biggest difficulty was the lack of any method of guiding the fighters onto their targets...without any navigational aids, the Hurricane pilots could do nothing more than grope in the dark...] a much more fundamental drive was underway to improve the overall performance of the Hurricane. As far back as the outbreak of the war, the Air Ministry and Sidney Camm himself had recognised that the plane would soon head for obsolescence unless changes were made. Indeed, in early 1940 the government briefly discussed the idea of phasing out the hurricane altogether in 1941, forestalling the need for any design improvements. 'As policy was to concentrate on the Spitfire and the Hurricane production programme was to be completed by July 1941, it was not necessary to increase the performance of the Hurricane as it had been done with the Spitfire,' concluded a research meeting of the Air Ministry in February 1940. But this negative outlook never gained any traction, particularly as the Hurricane was proving itself in combat and the Spitfire production was so badly behind schedule. The more realsistic alternative to pahsing out the Hawker palne was to enhance its capability through the introduction of a more powerful engine and high-calibre weaponry.
By early 1940 Rolls-Royce had developed a more advanced version of the Merlin, featuring a two-stage supercharger. Called the Merlin XX, it delivered 1300 hp, compared to 1,030 from the original. It also gave a stronger performance at altitude and raised the efficiency of the engine because it used a mix of 30% glycol and 70% water, rather than pure glycol.... Camm sent the Air Ministry a proposal to install the engine on the Hurricane. He emphasised that no design changes were needed in the plane to accommodate the new power-plant, apart from slightly longer front fuselage and a larger coolant radiator. The Air Ministry approved the proposal and told Hawker to produce the prototype of what soon was officially entitled the Hurricane Mark II Series A.
In May the arrival of Lord Beaverbrook at the Ministry of Aircraft Production (MAP), combined with the growing intensity in fighter combat, gave new emphasis to the Mark II project. On 24th May 1940, MAP agreed that the Hurricane II must have first claim over the Spitfire and Beaufighter on Rolls-Royce's production of the Merlin XX because of the vital need to improve the Hawker fighter's performance...
the first [production] models emerged from the Langley works in September 1940, going into service initially with 111 'Treble One' Squadron and then replacing Mark Is in other Fighter Command units over the coming months.
...Bob Foster of 605 Squadron recalled his satisfaction 'it is no exaggeration to say that everyone was pleased with them. They had a Merlin XX engine which gave us higher speeds and a much better rate of climb. In the air the superiority of the Mark II was evident. [Tom Neil of 249 Squadron reported] 'The manually controlled two-speed supercharger, when engaged, came in with a disconcerting thud but increased the performance above 20,000 ft very substantially.' In the Mark I , Neil had never been optimistic going into combat above 25,000 feet whereas the Mark IIA 'was still pretty active at something over 30,000 feet'.