(different title used on original text)
by "L.G." Smith, July 1997
In the early days at Savoy Hill, there was
a Development Section housed in a room adjacent to the Control Room on one side,
with a Research Section in a room adjacent to the Control Room on the other
Equipment such as amplifiers were provided
by Marconi or Western Electric. These were huge units in mahogany boxes Ė a mic
amplifier for instance was 6 ft. long by 4 ft. high by 2 ft. deep in 1923.
Switching was carried out by plugs and jacks housed in mahogany switchboards
mounted in desks following standard G.P.O. telephone practice.
Since a great deal of "Design" work was
associated with BBC/GPO equipment a section of BBC engineers formed a "Lines
Section" and, under a Mr. Atkins (I think ex GPO or STC), were responsible for
the rebuild of the first BBC Control Room at Manchester in the mid/late 20ís.
This used rack mounted equipment with
overhead cable racks, all finished in a GPO green/grey finish. Control positions
continued to use mahogany mounted switchboard type equipment following GPO
telephone practice. Programme switching of the lines and studio outputs,
however, was attempted using Strowger two motion selectors again following
telephone switching practice, with telephone connections using plugs and jacks.
This type of selector switching was never
satisfactory. Connections over the selector contacts, although acceptable in
telephone practice were noisy and the selector operation was unreliable. They
were only kept operational through the efforts of two Senior Maintenance
Engineers Ė Messrs. Purslow and Hamilton and were finally replaced by relays
with platinum/gold/silver (pgs) contacts in the mid. 30ís.
Following this failure of Lines Section to
design satisfactory equipment, a small Designs Section of Equipment Dept. was
formed in the late nineteen twenties . This consisted of Mr C.H Colborn and J.E. Locke as engineers with
Holden and Mackinley (ex Relay Automatic Telephone Co. of Brixton Hill) as a
small drawing office. All accommodated in one room in Avenue House, Clapham.
It is difficult to appreciate that during
the late 20ís and early 30ís there was virtually no commercial equipment
available up to the standards required by the BBC and components such as
transformers, volume controls and resistors for instance were designed and
manufactured within Equipment Dept.
There was also at Savoy Hill a "Station
Design and Installation Section" headed by Mr. B.N. McLarty. This was
responsible for the design of transmitters and power supplies, mains supplies,
batteries and charging equipment for all BBC premises. (All studio and control
room equipment operated from batteries until 1936).
Close liaison was required between Mr.
Colbornís Section and Mr. McLartyís with regard to the provision of 300v H.T.,
6v L.T. and grid bias supplies, all from batteries
The first result of Mr. Colbornís Section
was the re-equipment of Edinburgh Control Room where the old mahogany desks and
tables were replaced by "BBC" grey rack mounted equipment and control desks,
using relays with pgs contacts for the main programme switching of studio
outputs and incoming and outgoing lines. This Edinburgh project was carried out
towards the end of the 1920ís and served as a prototype for the design of
equipment for Broadcasting House in 1930/31/32. The production of Broadcasting
House equipment required an expansion of Mr. Colbornís Design Section, in
particular by the introduction of two engineers who specialised in the design of
cableforms and the expansion of the Drawing Office into five draughtsmen, the
whole Section being accommodated in an asbestos clad bungalow built in the
grounds of Avenue House, Clapham
During the 1930ís this Designs Section
carried out the re-equipment of all the Regional Centre Control Rooms and the
Section expanded to cover such aspects of technical equipment as the OBA/8 and
the first mobile recording van which used disk equipment.
Also throughout the 1930ís Lines Engineers
retained some design work that related to the testing and operation of GPO
lines, such items as portable repeaters, amplifier detectors and transmission
measuring sets, but this equipment was badly designed from the manufacturing and
maintenance point of view, many components being only accessible by removing
others and the equipment also needed re-designing for rack mounting. This was
done by Mr. Colbornís Design Section.
Research Dept. moved out of Avenue House
during the 30ís ,first to Nightingale Lane and then to Nightingale Square in
Clapham. Whilst there, they were responsible for the design of the OBA/7
equipment as a replacement for the old Marconi GA/2, but this design was a
failure, being too heavy and complicated for use at an outside broadcast site.
It took two men to carry the amplifier and had a generator for H.T. supply. Many
regions took their set to the most used O.B. and left it there. Research Dept.
were also responsible for the development of recording equipment.
By 1930, thoughts were being given to a
redesign of control room switching equipment to replace the use of relays which
had given excellent, reliable service since it had been installed. A motor
uniselector was available from Messers. Siemens as used by the GPO to replace
the old two motion selector. Some of these were obtained and an experimental
bank of six with rhodium plated contacts for programme circuits were set up with
associated relay circuits by Mr. H.D. Ellis who had transferred from Research
Dept. to work in Mr. Colbornís Designs Section.
This worked exceptionally well and the
design of equipment for Broadcasting House Control Room was well advanced when
war came in September 1939.
All engineers in Designs Section were
scheduled to be dispersed to various operational transmitters, etc. in time of
war, it being considered that no "design" work would be required. In practice,
much more urgent design work and installation activities were required. Cheap
equipment on wooden panels, emergency facilities of all kinds, expansion of
overseas broadcasting, etc.
Engineers with design and installation
experience were recalled for major projects such as 200 Oxford St.,
Bush House, Emergency News Headquarters, etc. and continuing work in
In 1941, Mr. Colbornís L.F. Design Section
was transferred from Equipment Dept. to Station Design and Installation Dept.
under Mr. B. H. McLarty.. S.D.I.D. had been evacuated from premises near
Broadcasting House to Droitwich at the outbreak of war and some of Mr. Colbornís
engineers went with them. Those working in London with Mr. Colborn took up
office residence in the Langham Hotel.
As early as 1943/44 thought was being
given to post war equipment. A small team under Mr. H.D. Ellis produced the
Studio Type "A" Equipment, the first model of which went into service in
December 1944. This was the BBC's first mains operated equipment specifically
designed for studios.
Between 1944 and 1947 the number of
engineers working for Mr. Ellis increased and the name of the Department, of
which Mr. Ellisís group formed one section, was changed from Station Design and
Installation Dept. to Design and Installation (D.I.D.) in 1946.
From the late 1920ís Lines Dept., whose
main responsibility was the close liaison with the GPO in the provision and
operation of all BBC line requirements, had been responsible also for the design
of equipment directly associated with the testing of lines Ė such as portable
tone sources, repeaters, equalisers, etc.
So that in May 1947 a Designs Dept. in its
own right was formed from those engineers in Lines Dept. working on equipment
design and the group under Mr. Ellis working on studio and control room
equipment. Mr. H.B. Rantzen from Lines Dept. was appointed head of the new
department and one of the first fruits of this was the production of automatic
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