Early British Remotely Controlled Guns and Barbettes

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Robert Hurst
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Early British Remotely Controlled Guns and Barbettes

#1

Post by Robert Hurst » 11 Apr 2003, 15:24

Hi

In the mid-thirties several British aircraft companies were considering the manufacture of new bombers. One of the major considerations of such designs was defence against opposing fighters, which, for reasons of 'time on target' and minimum deflection allowances, attacked mainly from the rear. This presented problems for the bomber designers: ideally a rear gunner had to be placed in a position beyond the the tail. This meant a large extension of the fuselage, and with speeds continually increasing. The gunner needed a heavy and performance-reducing powered turret. Any solution which could avoid such a heavy penalty would be beneficial to the aircraft. Consequently, several design teams devoted time and effort to a system of remotely controlled guns, operated by a gunner in a remote cockpit.

The Blackburn Turret.

The Blackburn remote turret appeared to be the most promising design. As shown in the diagram, this was to be an all-electrical system. Patent No. 515993 was taken out in 1936 by Blackburn Aircraft Ltd, Messrs G E Petty and A E Mills. The designers stressed that reduction in turret size was a prime consideration. It would appear that this was achieved, resulting in a scheme not unlike that of the Boeing B-29 Superfortress of 1942.

The gunsight and handgrip were connected electrically so that the turret followed the movement of the sight, similar to the Nichols system in the Rose turret. The turret was rotatable about the horizontal and vertical axes by separate servo motors regulated by the control gear. Four Brownings were to be mounted in a spherical turret, 'A' in the diagram, a detachable cover 'B' giving access to the guns for loading and service. For elevation of the guns, the turret rotated about axle 'C' to which was secured a worm-wheel segment adapted to a slide in the guide shoe of the freely rotatable drive unit 'D', carrying the actuating worm and motor 'E'. The ends of the axle projected beyond the turret shell on each side, and were mounted in bearings which slide in guide ring 'H', attached to the fuselage structure and permiting horizontal movement. This movement was effected by motor 'G' bracketed to a bulkhead and driving a worm meshed with ring gear 'H' attached to the bearings supporting the axle. The driving unit 'D' was turned about its vertical axis by the guide shoe maintaining its driving worm in engagement. The electric-motors were connected by cable to the gunner's turret by some unmentioned control system (probably a version of the Ward Leonard control system). The rotation of the gunner's seat caused the motor 'G' to give a corresponding traversing movement to the gun turret. A reflector sight was mounted on arm 'J', pivoting from the seat structure as this was elevated, the electric motor 'E' giving corresponding movement to the guns. An operating handle 'K' was pivotally connected to the arm carrying the sights, and on this was mounted the electrical-solenoid firing control for the guns.

As shown in the diagram, the gunner's observation dome was very small, with a field of view leaving much to be desired. Although this system is not shown as a tail defence unit, it could have been adapted to any position. It was mentioned that the system could also be applied to other uses, such as cine cameras. Rocking the grip fore and aft controlled two bellows below the grip, moving the guns in elevation. No mention was made of ammunition supply, but it would appear belt boxes would be fixed under the guns which would have to be fitted with a firing mechanism
and heaters, John North of Boulton Paul also devised a similar system of remote control.

John North's Outriggers

At about this time (1935) aircraft designers were devoting much time and energy to the problem of rear defence systems. L G Frise of Bristol used a gun offset system in his B.1 turret, and other manufacturers extended the fuselage and installed a powered turret or open gunner's cockpit behind the tail. Another possible solution was the use of remotely controlled guns. In March 1935 a patent (No. 515992) was taken out in the names of Boulton Paul and John North for a system in which 'the guns are mounted in members projecting from the aircraft body'. This, it was claimed, increased the field of fire and reduced the size of the gunner's enclosure. The patent specification was as follows:

In view of the difficulty of providing an unobstructed field of fire past the tail of the aircraft, the examples given in the specification are all confined to the rear end of the aircraft. In the various sketches the reference letters are 'A' tailplane, 'B' elevators, 'C' fin, 'D' rudder, 'E' the projecting support member, and 'F' the gun carrier. The mounting for a single group of guns in what is the simplest form is given in Figure 1. The support member is a tube mounted below the body in two bearings, and capable of rotation through 360 degrees. To the end of the tube is hinged the gun carrier, which may be moved through an arc of at least 180 degrees. It will be noted that in the elevation the pivoted axis of the carrier is horizontal, but in plan view the support tube has been turned through 90 degrees, and the pivoted axis is now vertical. Thus the gun may be aimed at any target within the rear hemisphere of the aircraft.

An alternative single mounting is shown in Figure 2. Here the support member swings in the horizontal plane, through an arc of more than 180 degrees from a turntable under the tailplane, while the carrier is rotatable through 360 degrees in the vertical plane from a second turntable on the end of the support. Figure 3 shows a more elaborate multi-gun layout applied to a large aircraft. The body is extended beyond the tailplane to furnish a windowed cabin for the gunner, and has two rigid lateral extensions. To these extensions the support members are pivoted through 180 degrees in the horizontal plane. On the ends of the support members, pairs of guns are rotatable for elevation on the turntables in the manner of Figure 2. As indicated by the arc 'H', the wide range of fire is limited only by the elevators and wings. It will be seen that the guns on either side of the gunner's cabin may be trained on either side of the aircraft, the guns on the remote side firing past the end of the cabin.

The lateral extension 'G' and the support members are of hollow design, to accommodate the operating mechanism, firing control leads and ammunition belts. A simple manually controlled gear for aiming the guns is described in the patent, but 'any known means of control can be employed'.

It would seem that accurate sighting would have been difficult. No reference was made to the method of interconnecting the sights, except the statement:

Such a gunner would be provided with sights mechanically interconnected to the gun casings, in such a manner as to ensure that the sight line and line of fire of the guns shall be either parallel, or shall converge at a specific range from the gunner.

It is obvious that this system of outriggers would have needed a great deal of development, but it could have been made to work. The routing of the ammunition belts would have needed much ingenuity, to say the least. It is probable that the successful Type E tail defence turret was the outcome of North's work on his outrigger idea.

The above text and photos were taken form "British Aircraft Armament Vol.1: RAF Gun Turrets", by R Wallace Clarke.

Regards

Bob
Attachments
John North's Outriggers.jpg
John North's Outriggers.jpg (19.78 KiB) Viewed 1178 times
Blackburn Remote Turret of 1936.jpg
Blackburn Remote Turret of 1936.jpg (31.21 KiB) Viewed 1178 times

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Robert Hurst
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Joined: 04 Oct 2002, 16:11
Location: Worksop, Notts, UK

#2

Post by Robert Hurst » 12 Apr 2003, 11:06

Hi

The Bristol Type 147

In 1935 the Bristol Aircraft Company, submitted a design for the Air Ministry specification F.9/35(NF), to be known as the the Bristol Type 147. This was for a two-seat night fighter to be fitted with a remotely controlled flush-fitting four-gun dorsal turret. The gunner sat at a sighting position just behind the pilot, and he controlled the guns by manipulating two handwheels. The wheels moved a reflector sight which was mechanically connected to the guns. The specification mentions movement through 90 degrees in elevation and 180 degrees in azimuth (rotation), although a study of the diagram would cast doubt on these figures. The Type 147 was not accepted. It would have been interesting to see details of the sight/gun linkage system, but no drawings have survived.

The Fairey Remotely Controlled Turret

In May 1935 a patent was taken out in the name of the Fairey Aviation Company and Mr E Voss (Patent No. 515991) for a remotely controlled turret system. Mr Voss claimed, 'The remote control permits the adoption on the aircraft of the best sighting position for the gunner, the best firing position for the guns, and the most adequately protected position for the driving mechanism'. In the proposed Fairey system the guns and sights were to be mechanically coupled. The patent drawings show two sketches, the first being a layout of the installation (Fig. 1), the second (Fig.2) a detail of the sighting turret. The system was described as follows:

Four guns are mounted in turret 'A', which is rotatable in a horizontal plane by means of a pinion 'B', meshing with an external ring gear 'C'. Elevation of the guns in a vertical plane is effected by a worm 'D', meshing with a worm quadrant 'E' secured to the gun table. A similar pinion and ring gear rotates the sighting turret, while the sights are actuated from the driving gear by a mechanical linkage. The gunner is provided with an adjustable seat and a head rest 'F' for convenience when viewing through the sight. Both traversing and elevating movements are effected by a single power unit 'H', electrical or hydraulic. The drive is through an infinitely variable and reversible gear box 'J', controlled from the right-hand grip 'K' in the sighting turret. By rocking the grip left or right, the gunner actuates two small hydraulic bellows mounted above the grip, controlling the direction and speed traverse.

The above text and sketches were taken from "British Aircraft Armament Vol.1: RAF Guns and Turrets", by R Wallace Clarke.

Regards

Bob
Attachments
Fairey Remote Turret of 1935.jpg
Fairey Remote Turret of 1935.jpg (35.55 KiB) Viewed 1176 times
Bristol Type 147.jpg
Bristol Type 147.jpg (53.53 KiB) Viewed 1177 times


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