Tag Archives: Rolls-Royce Merlin

Hawker Hurricane

IN AUGUST 1940 THE HURRICANE AND SPITFIRE WERE ALL THAT STOOD AGAINST HITLER’S NAZI GERMANY

Unlike the beautiful Supermarine Spitfire, the Hawker Hurricane has a stubby, hunched, rugged old soldier, look about it.  Unlike the complex Spitfire, the Hurricane was easy to manufacture and repair.  It also took half as long to refuel and rearm, was easier to fly and more maneuverable near the ground. The Hurricane cold carry heavier armament and was a better gun-platform than the Spitfire.  The Hurricane was simple and tough, and although nowhere near as fast or with a rate of climb to rival the Spitfire, it was an operational go-anywhere, do-anything fighter by the time of the Battle of Britain.  The Hurricane was a workhorse to the Spitfire’s thoroughbred.

Hurricane_IV

Hurricane IV with 4 ~ 20mm cannon

BF109 Bouchon

Bf 109 bouchon

The Hurricane was in the thick of the action well before the Battle ofBritain as part of the British Air Forces in France, with 6 Hurricane squadrons from January 1940.  A further 4 Hurricane squadrons were sent to France when the German offensive began, followed by another 2 on May 13th 1940.  The French Air Force, (Armee de l’Air), was so ineffective in 1940 that on May 14th the French Government then asked for another 10 squadrons of Hurricanes ~ after much heart-searching only 3 more Hurricane squadrons were committed, and these returned to England at night.  In the end, by the time of the Miracle of Dunkirk, over 200 Hurricanes had been lost, many of which would have been repairable had they not been operating from forward air bases in France.  England committed a greater proportion of its air strength to the Battle for France, than the French did, 30% as against 25%, and at such a cost that the Battle of Britain was a damn close run thing.  (The 1969 film: Battle of Britain gives a reasonably accurate account of the battle.  However the Bf 109’s in the film are powered by Rolls-Royce Merlin engines.(Hispano Aviacion Bf109 Bouchon)).

In any form, the Bf109 outperformed the Hurricane except in tight turns at low altitude.

Specification; Hawker Hurricane Mk IIB

  • 1,280 bhp Rolls-Royce Merlin XX
  • Span 40 ft,  Length 32 ft,  Wing Area 257.5 sq ft,  Weight 5,500 lbs (MTOW 7,300 lbs)
  • Maximum Speed 342 mph at 22,000 ft
  • Service Ceiling 36,000 ft
  • Range 480 miles
  • Armament 12 .303 machine guns plus up to 1,000 lbs bomb load

Designed by Sydney Camm and entering service in 1937, the Hurricane was the first of the RAF’s monoplane fighters, and became the first operational RAF aeroplane capable of exceeding 300 miles per hour.   It used the same legendary Rolls-Royce Merlin engine as the Spitfire, which at the time of the Battle of Britain produced 1030 brake horse power.  Eventually the Hurricane would be fitted with the two-stage supercharged Merlin 27 which gave 1635 bhp.  These engines were mounted in a fuselage which had a lot in common with earlier, biplane fighters.  There was an alloy frame to which were mounted wooden stringers and then covered in fabric.  Only the area around the engine had an alloy skin.  Early Hurricanes even had outer wings covered in doped fabric.  Unlike the beautiful, elliptical, wing of the Spitfire, the Hurricane’s wings were simple in design and construction.  This rugged construction was the logical outcome of a long line of Hawker fighting aircraft.

Battle of Britain Memorial Flight

Battle of Britain Memorial Flight

The thing about the Hurricane’s simple wing was that all the guns could be grouped close together, outside of the propeller arc, and heavier armament could be fitted than the Spitfire’s thin, elliptical, wings could accommodate.  The Hurricane was the world’s first 8 gun monoplane fighter, at the time of the Battle of Britain most Hurricane’s were fitted with 8 Colt-Browning 303 machine guns.  Later Hurricanes could be fitted with 12 machine guns, or 4 20mm cannon, or even with twin Vickers 40mm S cannon and 2 machine guns for use as tank-busters.

Some 1,715 Hurricanes took part in the Battle of Britain, (29 squadrons as against 19 Spitfire squadrons), and between them its pilots destroyed 80% of the Luftwaffe aircraft shot down between July and October 1940.  Sadly, inexperienced Spitfire pilots were known to have mistaken Hurricanes for the Bf 109 and attacked their brother RAF aircraft.  The usual tactic for a mixed formation of Hurricanes and Spitfires was for the Hurricanes to stay lower down and attack the bombers, while the Spitfires flew top cover and tackled the enemy fighters.  Obviously the bombers were the easier target.  However, it is fair to say that this reliable aeroplane has never been given all the credit it deserved for winning the Battle of Britain.  Older and slower than the Spitfire it may have been, but there were more of them.  (Hurricane: Victor Of The Battle Of Britain by Leo McKinstry.)

TRANSPORT Hurricane/Duxford

wrecked Hurricane (photo from Daily Mail)

The Hurricane was a remarkably versatile aircraft.  At a pinch it could be flown as a night-fighter as the wide-track undercarriage made it possible to land a Hurricane in the dark.  From 1942 the cannon-armed IIc operated as a night intruder over occupied Europe.  In the North African desert, tropicalised Hurribombers armed with 4 20mm cannon and 500 lbs of bombs, gave the axis a taste of what to expect from Hawker fighter-bombers.  The Hurricane was supplied to Russia under Lend-Lease, although the 2,952 aircraft delivered weren’t much liked by soviet pilots.  The Sea Hurricane became operational from 1941 and stayed in service for 3 years.

Perhaps the most dangerous, (for the pilot), variant of the aircraft was the Hurricat.  Because of a shortage of aircraft carriers for convoy escort work, some merchant ships were fitted with a rocket-propelled catapult to launch a single Hurricane fighter.  Amazingly, pilots were found for the Hurricanes fitted to these CAM ships.  If all went well, the Hurricane would shoot down the German reconnaissance aircraft shadowing the convoy, and then the pilot would bail out, or ditch in the sea, to be picked-up by the convoy escort.

CAM-ship_hurricaneoncatapult

CAM ship with Hurricane on the catapult

This unpretty fighter was in the right place at the right time.  Early Hurricanes had a wooden, two-bladed, propeller and no armour plating.  But even when these shortcomings were rectified, the aircraft had a limited development potential because of its antiquated frame and fabric fuselage.

The real story is that, without the Hawker Hurricane Britain could have lost the war.

~

jack collier

jackcollier7@talktalk.net

One of the few

Supermarine Spitfire IX

109 and spitfireThe Supermarine Spitfire had the measure of the Messerschmitt Bf 109 all throughout WWII, but then in 1941 the Germans did something different.  A small, neat, radial-engined fighter appeared, and the Focke-Wulf 190 slaughtered the RAF’s premier interceptor.

It took Rolls-Royce and Supermarine about a year to produce the answer to the ‘Butcher Bird’, in the form of the Merlin 61 fitted into a long-nose airframe, and the combination became the Spitfire Mk IX.  Perhaps the definitive Spitfire variant, the Mk IX, first flew on 20 September 1941, and remained in service from 28 July 1942 until the end of WWII and beyond.

Spitfire-Mk-IXThe Merlin 61 had a two-stage supercharger with intercooler which boosted power from the 990 bhp of the Merlin II to 1560 bhp.  The Spitfire IX was some 40 mph faster than the MkV, and could reach an altitude of 43,000 feet ~ 6,000 feet higher than the Spitfire Vb.  The 190 was almost a match for the Spitfire IX below 20,000 feet, but above that altitude the Focke-Wulf was outclassed.

fw190ASuddenly it was the turn of Fw 190 pilots to be astonished , they were used to outflying Spitfires but the MkIX achieved superiority over both the Fw 190 and the Bf 109G.  The unpleasant thing for Luftwaffe fighter pilots was the deadly Mk IX looked exactly like the Spitfire V they were used to shooting down.

The Spitfire IX was the best Spitfire.  When we got the IX. we had the upper hand, which did for the 190s. ~ Johnnie Johnson.

Test Pilot Jeffrey Quill, who was instrumental in all Spitfire upgrades, described the Spitfire IX and it’s Rolls-Royce Merlin 61 engine as one of two quantum leaps in Spitfire performance during the war, (the other being the introduction of the Rolls-Royce Griffon engine).

Like many very powerful engines shoehorned into tiny fighters, the Merlin 61 was originally designed for use in high-altitude bombers, (see the Bf 109 D).  Rolls-Royce were the world leaders in supercharger technologies and the Merlin 61 used two blowers in series, one feeding the other and separated by an intercooler.  This crammed as much air as possible into the Merlin’s intake manifold.  The Merlin 61 needed a big four-bladed propeller to absorb all that power, and the Spitfire IX needed a second underwing radiator to cool the intercooler.  (Tricky for the Lutwaffe pilots to spot in the middle of a dogfight.)

The Spitfire IX weighed 600lbs more than the Mk V, and was usualy armed with two 20mm cannon and four .303 machine guns.  There was a variant of the Merlin, the 66, which was used to power a low-altitude version of the Spitfire IX, the Spitfire LF IX.  This was designed to better the Focke-Wulf 190 at low and medium altitudes, the 190’s preferred hunting ground.  At 21,000 feet the LF Spitfire IX was 30 mph faster than the Fw 190, better in the climb and vastly more maneuverable.

PRXIThe basic Mk IX also appeared as the modified photo reconnaissance Spitfire PR XI, which could cruise at 42,000 feet, well above the maximum altitude of the Luftwaffe’s best fighters, and fly to Berlin and beyond.

The Spitfire IX was also modified to meet the threat from very high altitude attacks by Junkers Ju 88R and P’s.  These German attacks were merely nuisance raids, but in order to meet them the armour and some equipment was stripped from the standard Spitfire IX, which allowed Pilot Officer Prince Emanuel Galitzine to chase a JU88P flown by Feldwebel Horst Götz and Leutnant Erich Sommer to 43,500 feet and damage the bomber before it could escape into cloud.  This was the highest altitude air battle of WWII, and ended the high altitude bombing of England.

V1And finally for this post, in order to meet the threat from V1 flying bombs, (an early cruise missile), Spitfire IX’s were stripped of their camouflage paint, the wings were waxed and polished to a mirror finish, the mirrors were removed, and the armour was taken out.  Then, if they were already in the air when the threat was detected, the Spitfire MK IX could catch and destroy the German Terror Weapons.  The preferred method of downing a V1 was for the Spitfire to put its wing-tip under the stubby wing of the V1, and then roll sharply.  This toppled the flying bomb, destabilised its giro, making it plummet into the ground ~ preferrably in a field somewhere.

~

Spitfirejackcollier7@talktalk.net

 

 

 

 

 

Messerschmitt Bf 109

BATTLE OF BRITAIN ~ THE GERMAN ADVERSARY

Bf109

Messerschmitt Bf 109

In the interests of completeness, after my posts on the Spitfire and Hurricane, some information on Germany’s most important fighter of WWII, the Me / Bf 109.  The 109 first flew in May 1935, saw service in the Spanish Civil War, fought with the Luftwaffe all through  WWII, and was still in service with the Spanish Air Force up until the end of 1965.  The 3 top scoring German aces of the war all flew the 109.  Designed by Willy Messerschmitt and Robert Lusser the Bf 109 was the smallest and lightest airframe that could accommodate the largest engines under development in Germany, a pilot, and as it turned out not enough armament.

Lacking the grace of the Spitfire, or the rugged charm of the Hurricane, the Bf 109 looked like the killing machine it was.  Straight line simplicity is about the best one could say about its shape.  Or that it looks like a deformed glider, which is exactly what the Bf 109 was.  It’s chief designer, Willy Messerschmitt, cut his aeronautical teeth designing gliders.  His PhD thesis was accepted even though it was the plans for a glider.

In 1935 the Bf 109 did have all the elements for a cutting edge fighter; a low wing monoplane of flush-riveted stressed skin construction, retractable undercarriage, enclosed cockpit and ‘heavy’ armament.  The Hawker Hurricane was not as up to date as the 109.  The Hurricane was also much larger, slower, and mostly heavier.  Even the Spitfire was a bigger aircraft than the Bf 109 ~ the 109 had a wing area of just about 70% of a Spitfire’s.

A quick look at a Spitfire in comparison with a Bf 109 shows that the RAF pilot had a sliding bubble canopy, which gave an excellent all-round view.  Until the introduction of the slightly better Galland Hood the Luftwaffe pilot had a heavy framed cockpit canopy to contend with.  Contemporary accounts from RAF pilots who sat in an 109, describe the pilots view as terrible.

Because there was a lot of glider in the fighter’s genetics, the 109’s small wings were beautifully thin, using leading edge slots and slotted trailing edge flats to increase the wing area.  The wing was not stressed by the landing gear, as its loads were taken by the fuselage.  This resulted in one of the 109’s operational weaknesses ~ a very narrow-track undercarriage.  There were a large number of ground accidents during the 109’s operational career, the 109 was proving to be a fatally unforgiving aircraft

The thin, clean, wings would result in another operational weakness in the 109’s later life.  Unlike the wings on most fighters of the time, the wings on a 109 were not designed to carry armament.  The initial specification issued by the German Air Ministry had called for an armament of only 2 rifle caliber MG17 machine guns, mounted in the fuselage.  When the news that both the Spitfire and Hurricane were 8 gun fighters, a third MG17 firing through the propeller hub was added to the Bf 109’s war load.  The difficulty of installing heavier armament would result in later marques of the 109 sprouting lumps and bumps all over the wings and forward fuselage.

db_605

DB 605

The very first 109 was powered by a Rolls-Royce Kestrel.  Production models mostly used the Daimler-Benz DB605, an inverted V12 of 35.7 litres (2179 cu in), generating anything from 1,000 bhp to almost 2,000 bhp.  Although the power output was remarkably similar to that of the 27 litre Rolls-Royce Merlin used in the Spitfire, there were two key differences.  The 109 had fuel injection against the Spitfire’s carburetor, which meant the 109 could pull negative G and the Spitfire couldn’t.  The smaller Merlin had better fuel consumption than the 35.7 litre DB605, which gave the Spitfire slightly longer operational endurance.  There was a third difference, the DB605 caught fire a lot more often than the better-built Merlin.

The Luftwaffe found it extremely difficult to augment the 109’s limited internal fuel capacity with external drop tanks.  Over England a mission lasting an hour was long.  A mission lasting an hour and a half was to have an in-flight emergency.  Many pilots were saved by the excellent glide characteristics built into the 109 by Messerschmitt, the erstwhile glider designer.

These then were the adversaries during the Battle of Britain.  The Hawker Hurricane was outclassed by the Bf 109, which in itself was the equal of the Spitfire in the air.

The first contests between the fighters of the Luftwaffe and the RAF took place during the Battle of France.  This was bad news for the RAF as its best fighter squadrons deployed to France were equipped with the Hurricane, a machine outclassed by the Bf 109.  At least the Hurricane pilots had more chance than RAF pilots flying the obsolete Fairy Battle.  (To be fair, the Fairy Battle was a fairly new design, it was obsolete while it was still on the drawing-board.)  Resisting the call to send more and more Hurricanes to France, the battle was lost and the RAF prepared for the coming air assault on England.

The Bf 109’s greatest asset was its speed, but that came at a price.  The small 109 was all engine, pilot, and fuel.  The narrow track undercarriage was extremely dangerous on a grass airstrip, many young Luftwaffe pilots never got the chance of a second flight in a 109, and during the Battle of Britain the Luftwaffe was often operating from grass airstrips.

One oft-forgotten disadvantage the Bf 109 suffered throughout its life was the petrol, (gasoline),  it had to use.  From early in the war RAF fighters used the 100 octane petrol first used by the 1931 Schneider Cup seaplane racers.  This provided the Spitfire with an extra 34 mph in Emergency Boost.  The 109, like the rest of the Luftwaffe, had to make do with 87  octane fuel throughout its life.

The Bf 109 fought in throughout WWII, its nadir coming with the advent of the North AmericanP-51  Mustang in the skies over Germany.  This remarkable aircraft gained air superiority ~ having a performance the Bf 109 just could not match.

BF109 Bouchon

HA-1112-M1L Bouchon

After the war the Bf 109 soldiered on as the Hispano Aviacion HA-1112, initially with Hispano engines and later with the Rolls-Royce Merlin.  This variant was officially the HA-112-M1L, but is invariably known as the Bouchon.  (These are the 109s seen in the 1969 film Battle of Britain.)   The aircraft was retired from active service on 27 December 1965.

Hawker Hurricane

IN AUGUST 1940 THE HURRICANE AND SPITFIRE WERE ALL THAT STOOD AGAINST HITLER’S NAZI GERMANY

Unlike the beautiful Supermarine Spitfire, the Hawker Hurricane has a stubby, hunched, rugged old soldier, look about it.  Unlike the complex Spitfire, the Hurricane was easy to manufacture and repair.  It also took half as long to refuel and rearm, was easier to fly and more maneuverable near the ground. The Hurricane cold carry heavier armament and was a better gun-platform than the Spitfire.  The Hurricane was simple and tough, and although nowhere near as fast or with a rate of climb to rival the Spitfire, it was an operational go-anywhere, do-anything fighter by the time of the Battle of Britain.  The Hurricane was a workhorse to the Spitfire’s thoroughbred.

Hurricane_IV

Hurricane IV with 4 ~ 20mm cannon

BF109 Bouchon

Bf 109 bouchon

The Hurricane was in the thick of the action well before the Battle ofBritain as part of the British Air Forces in France, with 6 Hurricane squadrons from January 1940.  A further 4 Hurricane squadrons were sent to France when the German offensive began, followed by another 2 on May 13th 1940.  The French Air Force, (Armee de l’Air), was so ineffective in 1940 that on May 14th the French Government then asked for another 10 squadrons of Hurricanes ~ after much heart-searching only 3 more Hurricane squadrons were committed, and these returned to England at night.  In the end, by the time of the Miracle of Dunkirk, over 200 Hurricanes had been lost, many of which would have been repairable had they not been operating from forward air bases in France.  England committed a greater proportion of its air strength to the Battle for France, than the French did, 30% as against 25%, and at such a cost that the Battle of Britain was a damn close run thing.  (The 1969 film: Battle of Britain gives a reasonably accurate account of the battle.  However the Bf 109’s in the film are powered by Rolls-Royce Merlin engines.(Hispano Aviacion Bf109 Bouchon)).

In any form, the Bf109 outperformed the Hurricane except in tight turns at low altitude.

Specification; Hawker Hurricane Mk IIB

  • 1,280 bhp Rolls-Royce Merlin XX
  • Span 40 ft,  Length 32 ft,  Wing Area 257.5 sq ft,  Weight 5,500 lbs (MTOW 7,300 lbs)
  • Maximum Speed 342 mph at 22,000 ft
  • Service Ceiling 36,000 ft
  • Range 480 miles
  • Armament 12 .303 machine guns plus up to 1,000 lbs bomb load

Designed by Sydney Camm and entering service in 1937, the Hurricane was the first of the RAF’s monoplane fighters, and became the first operational RAF aeroplane capable of exceeding 300 miles per hour.   It used the same legendary Rolls-Royce Merlin engine as the Spitfire, which at the time of the Battle of Britain produced 1030 brake horse power.  Eventually the Hurricane would be fitted with the two-stage supercharged Merlin 27 which gave 1635 bhp.  These engines were mounted in a fuselage which had a lot in common with earlier, biplane fighters.  There was an alloy frame to which were mounted wooden stringers and then covered in fabric.  Only the area around the engine had an alloy skin.  Early Hurricanes even had outer wings covered in doped fabric.  Unlike the beautiful, elliptical, wing of the Spitfire, the Hurricane’s wings were simple in design and construction.  This rugged construction was the logical outcome of a long line of Hawker fighting aircraft.

Battle of Britain Memorial Flight

Battle of Britain Memorial Flight

The thing about the Hurricane’s simple wing was that all the guns could be grouped close together, outside of the propeller arc, and heavier armament could be fitted than the Spitfire’s thin, elliptical, wings could accommodate.  The Hurricane was the world’s first 8 gun monoplane fighter, at the time of the Battle of Britain most Hurricane’s were fitted with 8 Colt-Browning 303 machine guns.  Later Hurricanes could be fitted with 12 machine guns, or 4 20mm cannon, or even with twin Vickers 40mm S cannon and 2 machine guns for use as tank-busters.

Some 1,715 Hurricanes took part in the Battle of Britain, (29 squadrons as against 19 Spitfire squadrons), and between them its pilots destroyed 80% of the Luftwaffe aircraft shot down between July and October 1940.  Sadly, inexperienced Spitfire pilots were known to have mistaken Hurricanes for the Bf 109 and attacked their brother RAF aircraft.  The usual tactic for a mixed formation of Hurricanes and Spitfires was for the Hurricanes to stay lower down and attack the bombers, while the Spitfires flew top cover and tackled the enemy fighters.  Obviously the bombers were the easier target.  However, it is fair to say that this reliable aeroplane has never been given all the credit it deserved for winning the Battle of Britain.  Older and slower than the Spitfire it may have been, but there were more of them.  (Hurricane: Victor Of The Battle Of Britain by Leo McKinstry.)

TRANSPORT Hurricane/Duxford

wrecked Hurricane (photo from Daily Mail)

The Hurricane was a remarkably versatile aircraft.  At a pinch it could be flown as a night-fighter as the wide-track undercarriage made it possible to land a Hurricane in the dark.  From 1942 the cannon-armed IIc operated as a night intruder over occupied Europe.  In the North African desert, tropicalised Hurribombers armed with 4 20mm cannon and 500 lbs of bombs, gave the axis a taste of what to expect from Hawker fighter-bombers.  The Hurricane was supplied to Russia under Lend-Lease, although the 2,952 aircraft delivered weren’t much liked by soviet pilots.  The Sea Hurricane became operational from 1941 and stayed in service for 3 years.

Perhaps the most dangerous, (for the pilot), variant of the aircraft was the Hurricat.  Because of a shortage of aircraft carriers for convoy escort work, some merchant ships were fitted with a rocket-propelled catapult to launch a single Hurricane fighter.  Amazingly, pilots were found for the Hurricanes fitted to these CAM ships.  If all went well, the Hurricane would shoot down the German reconnaissance aircraft shadowing the convoy, and then the pilot would bail out, or ditch in the sea, to be picked-up by the convoy escort.

CAM-ship_hurricaneoncatapult

CAM ship with Hurricane on the catapult

This unpretty fighter was in the right place at the right time.  Early Hurricanes had a wooden, two-bladed, propeller and no armour plating.  But even when these shortcomings were rectified, the aircraft had a limited development potential because of its frame and fabric fuselage.  Hawker’s next fighter, the Typhoon, employed a structure that was a mixture of a monocoque and steel frame skinned in alloy.  The monocoque tail structure of the Typhoon had a nasty habit of falling off in the earlier marques.

The real story is that, without the Hawker Hurricane Britain could have lost the war.

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