Google+ Panzerserra Bunker- Military Scale Models in 1/35 scale: Beaverette Mk III AA with Boulton-Paul type A turret - case report
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sábado, 18 de janeiro de 2014

Beaverette Mk III AA with Boulton-Paul type A turret - case report

Hello, Old Boys !!!
 I don't know if you guys remember, but this vehicle would be done in parallel with the Beaverettes Mk I and II.
  The kits of Beaverettes, from IMACO
Beaverbugs Mk I, II and Mk III AA prototype
      But unfortunately some key pieces were missing from the kit....
Where is the turret's lips???
      But the customer service of IMACO replied immediately (and Mr. Russel Wilson it's THE Guy !!!  Thanks, Russel....) and sent me the parts like the Flash . Thanks to the Gods, they arrived in good order and in great condition.
The two missing rear petals of  the turret landed in my workbench...
       But before we open the glue pot and sharpen the scalpel, let's talk about the history of this vehicle:
History:
      In the dark days after Dunkirk the British Army, the Home Guard and the RAF Regiment were in urgent need of armoured vehicles both to upgrade the standard of support offered to its infantry battalions and to counter the impending threats of invasion and expected fifth column activity. On the armoured reconnaissance vehicle side, stop-gap measures were seen in the potential armouring of civilian and semi-civilian chassis, and two major developments were the Beaverette - produced by Standard Motors - and the Humberette.
      The initial Beaverette was very much a temporary machine, the Mk I and Mk II variants being open topped and clearly traceable to their civilian ancestry. It was particularly widely used by Home Defence and Training units throughout the War. The Mk III was at least in theory a more workmanlike vehicle, being an entirely new design conceived and manufactured in prototype form in ten days - some 2½ times the period taken for the earlier model! Based on the Standard Motor Company’s 45 HP chassis the completely enclosed body was so different from the original models that it was renamed as the Beaverbug I.
      However, contemporary commercial and service references continued to use the name Beaverette so this is the name that will be used in this article. As yet another alternative, in RAF documentation terms the vehicle was recorded as the ‘Car-Armoured Type D’. 

The prototype:
       The Beaverette III was essentially a metal box built on to the Standard chassis mounting a cylindrical turret with a half-moon opening flap sectioning the front half. The first prototype was designed to take a Bren gun and had a single vertical slit at the front of the turret through which the weapon could be operated. In order to give a better field of view the half-moon hatch could be braced open. The turret itself was rolled from flat sheets welded together in the vertical plane while the rest of the body was based on flamecut plate and a combination of bolting and welding. The prototype was almost entirely bolted or riveted, including the roof of the vehicle. Initial drawings suggested front sidelights very low in the body but these were eventually recessed high on each side of the front plate. All vision ports were hinged and access hatches were incor- porated in the outer strips of the bonnet top. The right hand side panel shows a horizontal weld, suggesting that on this vehicle the panel was made from two sheets. Initially khaki overall, there is some evidence from retouched photo- graphs that the same vehicle was camouflaged in two or three colours.

Production hull:
      It is likely that there were no production models in exactly this form and the actual production units incorporated an increased amount of welding in line with the recommendations, initially proposed by Guy Motors and subsequently taken up by the War Office, that welding should be used wherever possible. This not only cut production time but produced a much sturdier vehicle. On the production hull seen in most photographs published, each corner and the roof edges were welded, the front wings were bolted and the right side bonnet strip was also bolted. The left side bonnet strip was clipped under an edge at the rear and held at the front by a threaded rod and wing nut. The two inner hood strips were hinged at the centre and were held closed by their own weight. Grab handles were fitted to open them up. Production sidelights were external fitments as was the single shielded driving light, the cable for which entered the body under the lowest radiator louvre.
      The outer bonnet strips sat on top of the front plate whereas on the prototype they were recessed behind it, and the side vision hatches were also simplified to a sliding plate running on four external studs and two set into the plate bearing on the opening. Bolting was still employed to mount the rear wheel arches to the body and the body to the chassis. Rear wheel access was gained by removing lhree nuls from body studs set around the arch. Production vehicles would carry the Bren, Lewis or Vickers K gun and the RAF converted some to take twin Vickers K weapons by widening me gun slot and modifying and me half-moon hatch. Evenlually lhis inslallation became an open top turret of similar dimensions as the vehicles so equipped were intended primarily for the AA role - in which they were quite successful against low level single seat fighter bombers during 1942-44. 
Turret modifications:
      In an attempt to increase the firepower of these vehicles and use up production capacity on turrets, the firm of Boulton Paul Aircraft obtained vehicles and experimentally installed a turret type A Mk II four gun turret in the place of the hand powered turret. The fitment was extremely tight, the lower turret ring diameter overhang- ing the flat top at each side by fractions of an inch. Inside the space must have been even tighter with the need to accom- modate the electrical rotation joints, am- munition bins and case collector bags. The top speed of the vehicles in normal role was a questionable 39 Km/h.         In the turreted configuration the additional turret weight alone was some 133 Kgs, rising to 275 Kg with guns and ammunition, which reduced the road speed and cross-country ability even further.
      The turret panels were not armoured and the access doors at the rear were retained on the prototype fitments. In order to seal the turret against the possibility of access to an attacking force it was proposed that the production fitments be based on the type A Mk VIII turret and have a rear cupola without access doors. One of the turrets (that fitted to RAF 56536) was modified after removal from the vehicle as an example. Aware that the rather ‘ersatz’ conversion to the type A turret constituted something of an overkill situation on the Beaverette for anything other than a purely AA role, and also that A Mk VIII turrets would be snapped up for aircraft fitment as fast as they were produced, the company proposed an alternative to use surplus type C Mk 1 turrets as fitted to the Lockheed Hudson and Halifax variants. 
Boulton-Paul turret type C Mk 1
      This two gun turret ran on a ring 12cms smaller than the type A (96,5cm rather than 109,2cm), was over 37 Kgs lighter and took up less space inside the vehicle. Proposals were submitted with installation sketches and artist’s impressions of the variant.
      However, as with the A turret conversion the fitment and operation was rather sophisticated in comparison with the crude concept of the Beaverette and neither prototype nor production models were built. The Beaverette continued to soldier on with single or twin hand-held weapons.
        Two Beaverettes Mk III (RAF 56536 and 56538) were modified with some changes in its basic structure was used for trials. The new cars shows absence of weld seams, no air grill in the hood and the side hatches were riveted. Compare the pics below:
Standard Beaverette Mk III
Negative view of the pic above...Notice the details...
Beaverette Mk III AA
Beaverette Mk.III AA in negative view
Notice the absence of side hatches, weld seams and air grill in the hood.
Beaverette Mk III AA - right side
Notice the details
      The increase of almost 300 kgs in the small vehicle sacrificed plenty the already modest performance of the light armored car, and one only prototype was built and the production was not authorized.
       But the interesting thing about this vehicle is the ability of people to try to solve complex problems in a simple way.
font: Aircraft Modelworld - June 1988

The Boulton Paul Type A turret:
Boulton-Paul type A turret in a Defiant two-seat fighter
      Boulton Paul was one of the two main innovators of gun turret designs for British aircraft, along with Nash & Thomson; they supplied large numbers of installations for British aircraft. Boulton Paul's designs were largely based on originals licensed from the French company SAMM (Societe d'Application des Machines Motrices), while Nash & Thomson concentrated on the FN designs originated by the firm's co-founder, Archibald Frazer-Nash. Boulton Paul's turrets were electro-hydraulic in operation; electric motors located in the turret drove hydraulic pumps that powered hydraulic motors and rams. This was more effective than electric motors alone, and did not require power developed by the aircraft's engines as did the hydraulic system utilized by the Nash & Thomson design. The turret type A was the biggest feature of the two-seat fighter Boulton-Paul Defiant. This fighter was virtually built around this turret.
Boulton-Paul Defiant . Notice the A turret just behind the cockpit
      The turret Type A could be traversed the full 360 degrees with the four Browning .303 machine guns raised from zero to 84 degrees.
      Each pair of guns was fed from an ammunition box in the lower part of the turret. 600 rounds per gun were carried, taking the weight of the turret with its armament to over 275 Kg. Forward of the ammunition boxes were a pair of canvas bags which collected the used rounds as the guns were fired. The gunner had a joystick type of control from which he could direct the turret traverse and gun elevation. In case of failure, the turret could be positioned manually via rotating crank controls. A button on top of the stick fired the guns when operated. When installed in the turret either via a step into the turret' s rear doors, or through the hatch in the bottom of the fuselage, the gunner would plug himself in, so to speak, to enable his own supply of oxygen and radio communication with the pilot. As the guns were in motion, pneumaticallyoperated fairings fore and aft of the turret helped with the air flow to reduce drag. The fairings themselves were of wooden construction.
       The Type A turret was developed into many versions, adapted to the requirements for use in aircrafts such as the Boulton-Paul Defiant Mk II, Handle Page Halifax Mk.VIII, Martin Baltimore Mk I, Blackburn Roc Mk.II, Armstrong Whitworth Albemarle, Consolidated Liberator Mk II and also as training aids mounted statically in rigs or on top of vehicles.
Type A turret in Defiant fighter. 264 Squadron RAF
Handle Page Hallifax Mk VIII
Martin baltimore Mk I
Blackburn Roc Mk.II
Armstrong Whitworth Albemarle
Consolidated Liberator Mk II
RAF gunners in training with type A turret
      The A turret was also seen as an ideal anti-aircraft weapon for use on small warships. The A Mk II P.B.1 and 2 were fitted to some minesweepers and patrol boats. They were basically the normal Defiant turrets, but with 10 deg of depression, which meant the elevation was reduced by 10 deg to 74 deg, and only partial rotation was available. A Beaverette prototype light armoured car was also built, fitted with the A turret, apparently as an aerodrome anti-aircraft weapon for the RAF.
       The Type A turret proved an efficient design, its low profile causing a minimum of drag to the aircraft. The Hele-Shaw-Beacham hydraulic variable gear system provided a very smooth operating movement in both traverse and elevation. The gunner's view was not ideal, being impeded by the guns and feed mechanism, but he had a reasonable view to his front and directly to each beam. The four Browning guns were mounted in pairs on either side of the turret, while to the gunner's front was the control table with the following operating equipment. 
Type A turret - interior view
      This control had two positions. When pulled to the rear 'Free' position the rotation drive was disconnected mechanically and the connections to the hydraulic elevation rams short-circuited through a bypass valve. When pushed forward to the 'Engaged' position, the turret was operational. 
      The gun master switch was a three-position switch marked PILOT, OFF, GUNNER. The PILOT position was never used and was disconnected, being in effect another OFF position; when the GUNNER position was selected the gun firing circuit was alive. 
      The control column - 'joystick' - was on the right of the control table projecting through a diamond-shaped aperture. Movement of the column controlled the output from the hydraulic generator, and thus the speed and direction of elevation and rotation. A grip lever on the column energised the elecrtic-motor armature when grasped, and a gun-firing button on the top of the column was operated by the gunner's thumb. 
      On the right of the control panel over the gun switch was the motor main switch, which when closed energised the field of the motor and was indicated by a red warning lamp. The turret could then be operated from the control column. 
      In the centre of the table was a red button. When this was pressed it connected a resistance in series with the motor field winding, which doubled the speed of the motor and enabled the gunner to change quickly from one target to another. The button was used only for short periods as it imposed an overload on the motor and hydraulic system. 
      If the power system failed the turret could be operated by a hand rotation mechanism. A small handle was stowed under the right armrest. This was fitted to a gear shaft and, with the disengaging lever to FREE, the turret could be rotated. It was also just possible to elevate the guns by pressing the back end of the breeches. To see how this turret was operated, take a look in this interesting movie. The life of an air gunner was pretty tricky!

      The four Browning Mk.II guns were mounted on their sides with the cocking levers upper-most: they were cocked by the usual looped lanyard. Four 600-round ammunition boxes were fixed in front of the gunner's legs, the ammunition belts being lifted from the boxes by the gun feed mechanism over 90 degree chutes. Spent cartridges and links were collected in collapsible bags below the guns. The guns were fired by electrical solenoid sear-release units; the gun button operated a relay which energised the releases. Sighting was by a Mk.IIIA reflector sight mounted on an arm which moved in unison with the guns, the sight switch being on the left of the control table. An adjustable floodlight controlled from a switch under the sight switch enabled the gunner to clear stoppages on night operations.
Turret - rear view

Boulton Paul turret type A
specs
Role4 gun light  turret
ManufacturerBoulton Paul Aircraft
Used in aircraftsDefiant Mk II, Halifax Mk.VIII, Baltimore Mk I,  Roc Mk.II, Albermarle, Liberator Mk iI
Motive powerBP electro-hydraulic system
Armamentfour Browning .303 Mk II MG
Firing controlMagnavox 24V selenoid
Amunition600 rounds per gun in boxes within turret
Firing control

Field of fire



Speed of operation  



Gun sight 

Diameter of ring

Armour protection     

Weight
Palmer hydraulic
transverse: 360°
elevation: 0 to 84°
normal: 24° per sec
high: 54° per sec
Mk.IIIA reflector sight
857mm
9mm face visor
170Kg (empty)
282Kg (with ammo)
Specs of Beaverette Mk III AA:


 Beaverette MK III AA  4x2
 (Boulton-Paul type A turreted)

TypeLight anti-aircraft armoured car
Place of origin United Kingdom
Production history
ManufacturerStandard Motor Company
Specifications
WeightMk III: 2.9 tonnes
LengthMk III: 3.10 m 
WidthMk III: 1.73 m 
HeightMk III: 2.30 m 
Crew2 (driver and gunner)

ArmourMk III: up to 9 mm
Main
armament
Four Brownings 0.303 (7.7 mm) in a Boulton-Paul turret type A
EngineStandard 4-cylinder petrol engine
46 hp (34 kW)
Power/weight17-23 hp/tonne
Suspension4x2 wheel, leaf spring
Operational
range
Mk III: 280 km
SpeedMk III: 35 km/h

The kit:
      As is usual to the IMACO kits, parts comes in an extremely sturdy plastic box with protective plasti-bubble inside, in separated bags. No damaged or broken part. 
      Russell told me that IMACO had an big up-grade in the Beaverettes Mk III kit, with details of interior and body with spare parts. Compare the new:
Beaverette Mk III - new parts
      ...with the old:
Beaverette Mk III - old example
      The better improve was the chassis: The old, with no internal details:
Old Beaverette Mk III chassis
   
  ... and the new:(many parts have not yet been implemented, such as the fuel tank, levers, etc. ...)




Well done, IMACO !!!
            Building the body. The kit provides the air grills, but in this version, we don't will use: The weld seams will be sanded.
Body under construction....No problems here...


    Yesterday, I advanced a few steps ...Turret time!!! My idea is to keep the turret with the possibility of being removed, to see details ....Starting by the turret top:
Keeping the guns base moving.firm, not loose
The .303 machine guns are very out, on the basis. I marked the positions ...
and carve grooves (0,5mm)  to fit the machine guns ...
Testing the .303 in the basis
Voilááá...Much better !!!

"lubricating" the joint with graphite powder ...Smooth, but firm ...
Now, working in the lower portions of the turret...
Gunner seat...Notice the details...
Pedals...
front details. 
Notice the new "table", with joystick in the right side...
      When the turret dry the glue, let´s work in the air-hydraulic sistem for the turret:
Air compressed vessel. Love my minilathe...
       Testing the turret in the chassis:
Ready for movement...
Enemy fighter at 2 o'clock !!
Details in the chassis: Valves for gas distribution ...
Pipes and pedals ...
The gun barrels from RBModels
two sets...
Pretty Girl !!!
With Beaverette Mk III (Bren)

More advances:
Working with metal...


I did the rear door stay mobile. I made new hinges, using scraps of PE.
The original resin hinges did not support the articulation work...
Open the door !!!!
Door open. With this, it will be possible to see the electro-pneumatic
system of the turret and its base.
Notice the rivets in the side hatch

       Time of metal work  in the turret also. Using PE scraps and cooper wire, I did the turret sights...





Testing...testing...

The cave !!!!
       Painting time: Vallejo primers in white and green...
but the turret is black ( see cammo in the pics below)

The cammo and the interior...

The interior with weathering.
Notice the pressurized system for the turret movements in scratch
What a mass!!
Electric system for the turret...
Testing..testing...
And I closed the body with the chassi...

Notice the dashboard...
As she dried glue, I'll take care of the details of the turret ....

Well, Gents,,,the project is finished...The IMACo kit is awesome, but it is not indicated for novice modellers. Let's go: The turret Boulton-Paul was detailed with copper wire, plasticard and decals made ​​on my laserjet. It was a delight detail this little monster ...
Turret in rear view. No "lips" (yet...)
Notice the turret panel...
Notice the front details...




       And the Girl, ready, armed and dangerous!
Beaverette Mk III AA Prototype - RAF Regiment - Air base defense

Beaverette Mk III AA Prototype - left side





Beaverette Mk III AA Prototype - right side
Beaverette Mk III AA Prototype - rear view
Beaverette Mk III AA Prototype - rear door open
Beaverette Mk III AA Prototype - Boulton Paul type A turret



Beaverette Mk III AA Prototype - RAF Regiment

Beaverette Mk III AA Prototype with Kojak, for size comparison
Beaverette Mk III AA Prototype with Beaverette Mk III Bren

Girls of the same kind...

Beaverette Mk III AA Prototype with Beaverette Mk III Bren - bird view
Beaverettes Mk I, II and IIIAA
Beaverette Family !!!
Beaverette Mk III AA Prototype - RAF Regiment - Air base defense
      Lads...Thanks for following!!!

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