.. Production Methods etc ..

When planned as a Shadow Factory, Grange Works was envisaged as a manufacturing unit only, working with facilities provided by the
parent organisation. The Tool Room (such as it was) consisted of a few key machines. tools for maintenance work only, while-duplicate sets
of tools for turrets already being rnanufactured in Birmingham were sent down to Grange Works. To get production started, Methods Engineers
were loaned from the parent factory until the initial difficulties were overcome. It soon became apparent, however, that a staff of engineers
would be needed permanently, and two or three men were asked to stay on to form the nucleus of an Engineering Department.

Originally there were four basic types of  turret of Boulton Paul design to be manufactured here, and were as follows :-
"C" Type - 2-gun .303" Browning.
"A" Type - 4-gun .303" Browning.
"K" Type - 2-gun Retractable Turret.
"E" Type - 4-gun .303" Browning.

There were several "Marks" to each type, however, covering rninor differences to suit various types of aircraft .

The t u r r e t s were used on Handley Page "Halifax" four-engined long range bombers, Armstrong Whitworth "Albemarle" bombers, and
American Lockheed "Hudson" and "Ventura" twin-engined bombers. The "K" type under-turret never reached the production stage at Cwmbran,
and a few, only were made at Birmingham.

To get production at the commencement was an arduous task. Green labour, with no factory experience whatever, was utilised , a few
key people only having been sent down from Birmingham. As might be expected, numerous difficulties presented themselves. Systems had to
be introduced; operators trained on the job (no Training School at that time being in existence), and methods of production carefully studied.
For a short while things were chaotic, but by dint of hard labour and perseverance the difficulties were ultimately overcome until each month saw the turret programme met.

Frequent modifications were required on each type of t u r r e t as a result of experience gained by the R.A.F. on actual operations, and it was a big handicap to be without an adequate Drawing Office, Engineering Department and Tool Room t o deal speedily with these changes which were so urgent, for although Great King Street could still make the duplicate tools on modifications where new parts were involved, where modifications were required to existing tools the obvious and only possible way was to carry them out at Grange Works. The Drawing Office, Tool Room and Methods Department were therefore increased. Duplicates of master drawings of  turrets were kept and amended by our staff  to instructions furnished by the designing firm, but liaison with Great King Street was made with reference to modifications, Grange Works undertaking all it could absorb with its available engineering personnel and facilities . The frequent introduction of these modifications resulted in Grange Works gradually and almost imperceptibly building up an efficient engineering group which was, as further war developments revealed, to stand the Factory in good stead.

In October 1941, plans were made for a large extension to the factory (96,000 square feet) to take care of a new manufacturing programme
of Fraser Nash turrets, as well as to house a proper Tool Room which would meet the increasing demand for both modification tooling and tools for new products, but this programme was cancelled just before the completion of  the extension building. Two new contracts, however, were received,  namely, Turret Repairs and the manufacture of a modified Rotax C1238 aircraft starter for use on tanks. These projects, too, were very successfully tackled by the Engineering Group here.

A portion of the Factory Extension was laid out for repairing 40 turrets per month. These were returned from Stations in varying conditions;
some having been severely battered while on operations, and others through crashes on land and sea.

As much use as possible was made of plant already delivered for the production of Fraser Nash turrets, and although Rotax was supposed to
have a spare set of production tools, on investigation it proved to be only 60 %, and these had to be modified to suit the change in types of machine
tools available to us. The Final decision to produce starters was made on 20th July 1943 and the first starter manufactured on 30th November 1943.
Between these dates, a brochure of plant and equipment was produced, together with a layout of the shop for M.A.P, approval; tooling schedules
were prepared, also manufacturing layouts; tools made or existing Rotax tools altered to suit new plant, and plant installed. Shop laid out and equipped with about 140 machine tools, and special assembly benches, tests and winding machines were built.

As the war progressed, it became evident that .303 guns on turrets were to be superseded by .5" guns, -and three types of such turrets became
familiar, namely :-
Boulton Paul "D" Type 2 - gun rear turret.
Boulton Paul "F" Type 2-gun nose turret.
Bristol B17 2-gun rnid-upper turret.

The Boulton Paul turrets were hydro-electric, whilst the B r i s to1 turret was electric throughout.

Grange Works was required to manufacture both the "D" type and "F" type, whilst Boulton Paul Aircraft, . Daimler and Parnall Aircraft as well as
Joseph Lucas Ltd were to build the "F" Type. The "D" type was designed first, and production commenced before the "F" type.

To gain tooling time, the "F" type was split up, each firm undertaking planning and tool design of certain parts, Grange Works' share being
the Cupola. Each firm sent to each other member firm in the group the planning sheets and tool designs, and each was responsible for making its
own slight adjustments to suit plant differences and getting the tools made. The scheme worked very well indeed, and to Grange Works fell the honour of building the first production turret. Grange Works had installed a new layout for hydraulic units, and these were supplied to the other firms in the group, with the exception of Joseph Lucas Ltd.

Regarding the B17 Bristol electric turrets, Grange Works produced a Lucas designed type M.G.55 Motor Generator set, comprising three units
in one assembly. This machine supplied energy for one Rotax designed gun elevating motor and one similar machined for rotating the turret. These
machines were supplied to the Daimler Co., Brockhouse Engineering Co., and the Bristol Aeroplane Co., who were building the turrets. To speed up
production of the motor generator sets, Great King Street planned and tool designed the M.G.55 and forwarded the designs to Grange Works for rnanufacture of tools or buying outside. Grange Works planned and tool designed, and also made t h e tools for the two Rotax motors, while Great King Street designed and build testing equipment and coil winding equipment for the M.G.55 machine, with the exception of the motor portion which Grange Work under took. Great King S t r e e t  a l s o provided armature impregnating equipment.

The foregoing gives a brief resume of the activities of the Grange Works Engineering Group, but it is felt that reference should be made to some general developments which enabled us to reach the production stages more quickly. Originality is not claimed, the experience of
other firms being used on which to build up our technique.

Zinc Alloy Blanking Tools

Following a visit to Bristol Aeroplane Company, where a blanking tool in 3/8" thick KM zinc alloy was seen, experiments were made immediately at Cwmbran. This visit to Bristol took place on a Friday, and by the following Monday evening a zinc blanking tool was in operation in the press. The part produced was a side plate in 22g. Dural, major dimensions in length and breadth being approximately 14" x 6", having a true radius on one side and two straight edges disposed at an angle joining it. In between the two days mentioned, a licence was obtained to purchase the zinc, an order placed, the zinc collected at Avonmouth, and the work on it carried out in the Tool Room. Details of this technique were made known in a brochure, and circularised to all who might be interested. This type of tool in no small measure, accelerated the production of the "F" type t u r r e t , to which reference has already been made.

"Meehanite" Cast to Form Dies

 Considerable time in tool making was saved on the M.G. 55 rnotor generator yoke tools by making raising die
blocks in Meehanite metal; the shape to be imparted to the job being cast, requiring only a file dressing operation. - Usually these dies are made
from high grade die steel and machined to dimensions. We were indebted to Messrs. Goulds Foundries Ltd.., Newport, for making these castings in
Meehanite metal.

Super-finishing Hydraulic Parts .

Use on production of t h e Foster
Super-finisher was made for  the final sizing and super-surface finishing of previously ground cylindrical parts, such as pistons and distributor
"stalks". By this means, longer life of units was made possible , together with greater functions of efficiency.

Hydraulic Rubber Press.

A 400 - ton Oilgear "Rubber" Press was purchased with the original plant installed at Grange Works. At first many doubts were expressed as to the wisdom of buying such a press, and although in the early stages it was used very infrequently, towards the end of the war very good use was made of it. Here again, knowledge was gained after seeing a 2,500-ton capacity press in use at Bristol Aeroplane Company, and far from regretting the purchase of our press, the only regret we had was that we did not purchase one of at least three times the capacity.