Parnall Type 381 Project
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No mention of a 'Type 381' in Putnam's 'Parnall', but the Type 382 was the 'Heck Trainer', so the time frame is correct.
Also, the turret designs used a separate designation system, using 'FNxx' type numbers.
cheers,
Robin.
Also, the turret designs used a separate designation system, using 'FNxx' type numbers.
cheers,
Robin.
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Of course it was an aircraft,
and the Parnall began to develop it from 1937 with Type 382 also in the same year,but
the study ended in 1939,and the aircraft never built,so we know the F11/37 contest was
for twin engined two seat turret fighter,so I am asking again,was this proposal submitted
to this competition or not?.
and the Parnall began to develop it from 1937 with Type 382 also in the same year,but
the study ended in 1939,and the aircraft never built,so we know the F11/37 contest was
for twin engined two seat turret fighter,so I am asking again,was this proposal submitted
to this competition or not?.
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robunos said:
Yes robunos, I checked and came up with the same information. FN** signified Frazer-Nash, a division of Parnall specialized in turrets.
I'm attaching the complete list of their models below.
What's bugging me though is that lark is speaking of a turret that could go under as well as over, and there doesn't seem to have been any turret of that kind, even as a project. :-\
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The Parnall design was largely based on F11/37
Turret schould be a Frazer-Nash design ,hydraulically operated and could take
2 two pounders,two 1/2 pounders or 2 Hispano 20mm cannon.
The turret was located in the mid-upper position,and the fixed turret-ring actually formed part of the main wing structure
so that loads caused by firing the guns were distributed througout the entire wing.
An alternate layout had the turret located in the 'mid-under' position below the wing centre section.
Turret schould be a Frazer-Nash design ,hydraulically operated and could take
2 two pounders,two 1/2 pounders or 2 Hispano 20mm cannon.
The turret was located in the mid-upper position,and the fixed turret-ring actually formed part of the main wing structure
so that loads caused by firing the guns were distributed througout the entire wing.
An alternate layout had the turret located in the 'mid-under' position below the wing centre section.
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I have a copy of AE 55, so here's a summary of the article.
In the late 1930s the Air Ministry became interested in aircraft armed with cannon, and aimed via predictor sights. These would automatically aim at the target, allowing for lead and bullet drop, as long as the gunner kept his sights pointing at the target. In 1927, the Air Ministry issued specification F.11/37, for a fighter armed with four 20mm Hispano cannon, turret mounted. Boulton Paul, Nash and Thompson (Parnall), and Vickers were asked to design the turrets and predictors.In August 1938, Nash and Thompson informed the Air Ministry that they were ready to proceed with the design of a turret capable of mounting twin "1 1/2 or 2 pdr guns" (I'm not sure which theses guns were to be. Perhaps Tony Williams knows?).
Such was the weight and bulk of the turret, a specially designed aircraft would be needed to test it. Also the test machine should be representative of any operational type.
Given the type number 381, indicating the first design of 1938, the test aircraft was to be powered by two Bristol Hercules engines.
The wing, spanning 63' 6", tapered in planform and was of large root chord and thickness, blending into the fuselage, and helping to compensate for the drag of the large turret. I was designed to be built in five parts, centre, powerplant, and outer sections, for ease of construction, maintenance, and repair. The centre and powerplant sections were all metal, the outers being wooden with a metal leading edge. Full span leading edge slats and trailing edge slotted flaps were to be fitted. The outer flap sections doubled as ailerons.
The two piece fuselage, 61' 3" long was a conventional monocoque type. The forward part was to be soundproofed with a 6" layer of material; the upper part was also to be skinned with 10 gauge sheet to protect against the gun blast. The rear fuselage was tapered, although long dorsal and ventral fins gave a parallel appearance, with a horn-balanced rudder at the extreme tail. Oblong fins and rudders were fitted close to the tips of the tapered, mid mounted tailplane.
Regarding the turrets, they were to mount 20, 37, or 40mm calibre guns, were between 7' 6" and 8' 6", depending on version, and weighed over 2,000lbs. Crewed by two, Gun Layer and Loader, along with 200 rounds, the turret was to be mounted in the centre section (the turret race formed part of the stressed structure) in either mid-upper, or mid-under positions. Parnall believed the latter would give improved performance.
Parnall produced some encouraging noises, regarding production cost and timescale, and several senior figures in the Air Ministry wanted the project to proceed with the utmost speed. However, other equally senior figures seriously doubted Parnall's ability to develop the 381 and it's turret. In the end, Air Marshal Sir Wilfred Freeman decided not to proceed with the 381, instead asking "Could we not adapt a Wellington or B.1/35 or other type for this test work?" This resulted in the well known.Wellington cannon testbed aircraft.
cheers,
Robin.
In the late 1930s the Air Ministry became interested in aircraft armed with cannon, and aimed via predictor sights. These would automatically aim at the target, allowing for lead and bullet drop, as long as the gunner kept his sights pointing at the target. In 1927, the Air Ministry issued specification F.11/37, for a fighter armed with four 20mm Hispano cannon, turret mounted. Boulton Paul, Nash and Thompson (Parnall), and Vickers were asked to design the turrets and predictors.In August 1938, Nash and Thompson informed the Air Ministry that they were ready to proceed with the design of a turret capable of mounting twin "1 1/2 or 2 pdr guns" (I'm not sure which theses guns were to be. Perhaps Tony Williams knows?).
Such was the weight and bulk of the turret, a specially designed aircraft would be needed to test it. Also the test machine should be representative of any operational type.
Given the type number 381, indicating the first design of 1938, the test aircraft was to be powered by two Bristol Hercules engines.
The wing, spanning 63' 6", tapered in planform and was of large root chord and thickness, blending into the fuselage, and helping to compensate for the drag of the large turret. I was designed to be built in five parts, centre, powerplant, and outer sections, for ease of construction, maintenance, and repair. The centre and powerplant sections were all metal, the outers being wooden with a metal leading edge. Full span leading edge slats and trailing edge slotted flaps were to be fitted. The outer flap sections doubled as ailerons.
The two piece fuselage, 61' 3" long was a conventional monocoque type. The forward part was to be soundproofed with a 6" layer of material; the upper part was also to be skinned with 10 gauge sheet to protect against the gun blast. The rear fuselage was tapered, although long dorsal and ventral fins gave a parallel appearance, with a horn-balanced rudder at the extreme tail. Oblong fins and rudders were fitted close to the tips of the tapered, mid mounted tailplane.
Regarding the turrets, they were to mount 20, 37, or 40mm calibre guns, were between 7' 6" and 8' 6", depending on version, and weighed over 2,000lbs. Crewed by two, Gun Layer and Loader, along with 200 rounds, the turret was to be mounted in the centre section (the turret race formed part of the stressed structure) in either mid-upper, or mid-under positions. Parnall believed the latter would give improved performance.
Parnall produced some encouraging noises, regarding production cost and timescale, and several senior figures in the Air Ministry wanted the project to proceed with the utmost speed. However, other equally senior figures seriously doubted Parnall's ability to develop the 381 and it's turret. In the end, Air Marshal Sir Wilfred Freeman decided not to proceed with the 381, instead asking "Could we not adapt a Wellington or B.1/35 or other type for this test work?" This resulted in the well known.Wellington cannon testbed aircraft.
cheers,
Robin.
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Regarding Specification F.11/37, the selected design was the Boulton Paul P.92, which would have used Boulton Paul designed turrets. This could also be a factor in the cancellation of the type 381.
Other points, the Air Ministry encouraged Parnall to design the Type 381 as closely as possible to the operational specification as possible, despite the fact that this called for a four gun turret, rather than the twin-gun one designed by Nash and Thompson for the 381. This seems odd...
Also, reading BSP3, it appears that the four-gun Nash and Thompson designed turrets for F.11/37 were also to be specified for the aircraft designed to meet Specification B.1/39, for a cannon armed heavy bomber, along with the B-P units.
cheers,
Robin.
Other points, the Air Ministry encouraged Parnall to design the Type 381 as closely as possible to the operational specification as possible, despite the fact that this called for a four gun turret, rather than the twin-gun one designed by Nash and Thompson for the 381. This seems odd...
Also, reading BSP3, it appears that the four-gun Nash and Thompson designed turrets for F.11/37 were also to be specified for the aircraft designed to meet Specification B.1/39, for a cannon armed heavy bomber, along with the B-P units.
cheers,
Robin.
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Star, the same turret wouldn't have been used in the upper and under position on the 381, rather two variants of the same basic design would be built, adapted for top or bottom mounting, as appropriate.
Looking at your list, we see FN22/23/24 "experimental only, cancelled at early stage." Could these be the three types of 381 turret, differing only in calibre of weapon mounted?
cheers,
Robin.
Looking at your list, we see FN22/23/24 "experimental only, cancelled at early stage." Could these be the three types of 381 turret, differing only in calibre of weapon mounted?
cheers,
Robin.
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robunos said:
Everyone seems to have got in on the act, Bristol apparently developed their own quad hispano turret design for the B.1/39 requirement.
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robunos said:
It's a possibility. However they appear between the FN21 (used on the Manchester) and the FN25 (used on the Wellington) which might suggest the FN22-24 were somewhat later than the Parnall 381 project.
Also the list is clearly about the "FN" (Frazer-Nash) turrets; your quotes all refer to the earlier name "Nash and Thompson" so I think the turrets in question must have been designed prior to the FN1. What do you say?
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According to the snappily titled 'British Aircraft Armament Volume 1: RAF Gun Turrets from 1914 to the Present Day', which incidentally, is where the FN designation list comes from, Nash and Thompson was the name of the company that made the turrets, Archibald Frazer-Nash being the chief designer, hence 'FN'. Later, of course, turret manufacture was moved to the Parnall aircraft works, as it's capacity was greater.
Looking again at the list, the types I mentioned are the only ones that mount cannon that come early enough in the sequence. Unfortunately, there are no dates given in the list. However the FN1 was the turret for the Hawker Demon, which entered service in 1936 or so, so the type 381 turrets must be later than this, and the above book states that the FN25,(Wellington ventral turret) was ordered into production in 1938...
cheers,
Robin.
Looking again at the list, the types I mentioned are the only ones that mount cannon that come early enough in the sequence. Unfortunately, there are no dates given in the list. However the FN1 was the turret for the Hawker Demon, which entered service in 1936 or so, so the type 381 turrets must be later than this, and the above book states that the FN25,(Wellington ventral turret) was ordered into production in 1938...
cheers,
Robin.
