On this page: Control Room | Dramatic Control Rooms
8A | 8B | Band Room | Waiting Room | Dressing Room
The Eighth floor contained the main Control Room, a large studio for orchestral and band music and a much smaller studio for debates and discussions.
The sloping roof on the east side of the building affected the layout of this floor to a considerable extent. As mentioned below, the studio tower stopped one floor down. Two of the four lifts at the front of the building terminated at the seventh floor, too. The Control Room was tucked neatly under the sloping beams.
The Control Room
The Control Room used a relay switching system to enable the complete chain of transmission between any studio and any outgoing line to be set up in the least possible time. There were stand-by facilities and the means of bringing them into circuit without delay should any equipment develop a fault during transmission. Signalling devices showed the approximate positions of any faults. There was much subsidiary equipment, including check receivers, line testing equipment, interval signal equipment and the Greenwich Time Signal apparatus.
The Control Room at this time did actually control the outputs of microphones in the studios. There were no amplifiers in the studios, instead the microphone outputs (or the output of a passive mixer if a studio had more than one microphone) were fed to the Control Room and amplified there.
The southern end of the room, above, contained the six control desks used for transmissions, in two groups of three. Between those groups were the simultaneous broadcasting and supervisory positions. The former routed the programmes passing through the control positions to any of the outgoing lines. The supervisory position provided monitoring facilities and acted as the central exchange for the Control Room telephone system. On the left were the racks of amplifiers and other equipment.
At the far end, beyond the final beam and better seen in the photo, right, were eight desks used for rehearsals.
A four-channel fade unit at one of the control positions. The two outer faders each controlled two sources, cross-fading between them. The central fader combined the outputs of the outer ones in the same way and the output of that fader was fed to the main control, lower left.
Although the meter looks like today's Peak Programme Meter, it isn't one. The PPM was not developed till about 1936 or '7 but it did retain the previously designed scale.
above - Part of one of the relay bays, showing three types of relay used in amplifier switching.
left - Two of the receivers used for checking the quality of transmissions.
right - Cables in the false floor, ending on terminal strips at the bottom of the 'A' amplifier bays and connecting them with the studios. High output, low impedance Microphones were connected directly to the Control Room through a balanced, screened pair. The cable, which could be up to 1000 feet long, connected through a step-up transformer to an 'A', or microphone, amplifier. High impedance microphones, such as condenser mics, needed a pre-amplifier in the studio, the required power being fed down the microphone cable. The power supply was by means of batteries, in duplicate throughout. The battery room was on the sixth floor.
above - Two of the 'B' amplifier bays. The covers have been removed from a 'B' amp near the top of the bay, and from a programme meter amplifier near the bottom.
left - The 'B' amplifier input switching relays. The back of part of these bays is seen in the picture above.
above - The back of the power board, showing the massive low tension busbars supported on the insulators.
left - One of the fuse bays
Work in the Control Room
A contemporary account of this area from the 1934 BBC Year Book describes "the work which fell to the lot of the Control Room Engineers not only in maintaining all the plant but in adding that human element which is so vital to the smooth running of broadcasting."
Throughout the "office" day there is a stream of memoranda pouring in from all the various departments of Broadcasting House, such as "Music," "Outside Broadcasts," "Productions" and many others who have an active interest in the work which is required of the Control Room. This flow is centred on a very small but vital section of the control room staff. As an example, there may be a very urgent request for a special microphone lay-out for a "stunt" item to be broadcast in an hour's time - this must be dealt with immediately. Equally there may be detailed instructions for a discussion between speakers in London and New York to be broadcast two months hence, and this requires filing under the date in question. And so it goes on - instructions for the studios to be used for each item of the day's transmissions and for all the numerous rehearsals, with special mention of particular requirements, instructions for recordings to be made by the Blattnerphone, and their subsequent reproduction to the Empire or in the "Home" programmes, details of outside broadcasts, of simultaneous broadcast arrangements, of productions to be controlled on the dramatic control panels, of engineering tests and of a hundred and one other things large and small which ultimately have their direct effect on the programmes as broadcast. Each evening the next day's "operation instructions" must be carefully prepared so that as soon as the first section of engineers comes on duty in the morning each man may know exactly what is required of him for the day. A slip here might easily mean a serious defect in a transmission. For example, a typing error of a D for a C in the special programmes made out solely for the engineers' use might easily cause the control engineer to become highly perturbed at receiving no response from Studio 3D; the speaker concerned meanwhile waiting calmly in Studio 3C for the red light to flick as an indication for him to begin his talk. Dead accuracy here, therefore, is an absolute essential, for once an operating engineer makes a mistake its effect is almost certain to become immediately obvious to the listening public.
Returning to 9 a.m. The fully charged batteries to be used for the day in supplying power to the amplifiers and the signalling and telephone systems have already been connected to the control room bus-bars by the battery engineer, and the discharged batteries, used the previous day, are being recharged by the motor generator sets two floors below the Control Room. The engineers who will be responsible for controlling the programmes are busy calibrating the programme meters on all control positions preparatory to the "line up" test with the Brookmans Park transmitters and the provincial stations. This latter test ensures that all amplifiers in the broadcast chain are adjusted to their correct gain, so that presently the control engineer in London will know that every transmitter taking the programme which he is controlling will be receiving the same input intensity. Similar tests are carried out from the provincial stations to London. Throughout the day all programme meters will be checked from time to time as a safeguard against any discrepancy which may develop...
The work entailed in controlling the programmes and setting up the required programme channels was described in the 1932 Year Book, as follows...
Each broadcast programme has to be continuously controlled by an engineer seated at one of the Control Positions. He has before him a controlling handle, with which he can regulate the volume of the transmission, one or more handles with which he can fade from one programme source to another, a row of keys controlling the signal lamps in all the studios in the building, and a set of special keys by which he is able to set up the particular circuits that he wishes to use.
The engineer has a schedule of the day's programme before him, and his first duty is to set up the circuits for the first two or three studios that will be in use for this programme, by means of the keys on his position. The operation of these keys will switch on the amplifiers required, energise the microphones in the appropriate studios, and bring the outputs of the amplifiers associated with these studios to the fade unit on this Control Position. All this is effected by means of relay switching, the relays being located on the apparatus racks. These relays also cause "engaged" lamps to light on all the Control Positions in both Control Rooms so that the engineer at this position knows that his circuits are set up correctly, and the engineers at other positions know that these particular studios are engaged.
When the programme is due to begin, the announcer in the studio presses a button which operates a buzzer in the Control Room and lights a green light on all Control Positions. The engineer on the particular Control Position which is controlling this transmission depresses a key which puts out these green lights, then throws the key in the opposite direction, which lights a red light in this studio, and also lights a red light associated with this studio on every Control Position. The red lights in the studio give the announcer the signal that all is ready and the programme begins. The engineers seated at other Control Positions take no notice of these lights, since they are not concerned with those particular studios at this time, and on seeing the red lights they know which studios are actually in use for a transmission.
The engineer at the Control Position keeps a continuous check on the programme by means of headphones and maintains the volume within the specified limits, the volume being recorded on a "Programme Meter" on the position. When it is necessary to change from one studio to another or from a studio to an Outside Broadcast, the engineer will set up the second circuit in advance and at the appropriate time will fade from one to the other by means of the fade-unit on his position.
...So we may leave the control engineer who, with his assistant, will be controlling one of the transmissions for most of the day. His assistant, incidentally, keeps a log showing, correct to the second, the time and details of all changes in programme sources, and of all technical faults as heard by wireless, even to a momentary "scratch." This log is of paramount importance to the programme staff in compiling their statistics, in addition to its primary engineering value.
The S.B. (simultaneous broadcast) engineer starts his turn of duty by checking up all programme and technical arrangements with the nearest provincial S.B. centres, for he will be responsible for ensuring that they receive the correct programme at the correct time, and for most of the day he will be dealing with at least three separate transmissions. He also sees that the Greenwich Time Signal is broadcast according to schedule.
In the meantime the lines termination engineers have been setting up and carrying out insulation, listening and other tests on the circuits to be used for the outside broadcast (O.B.) transmissions and rehearsals to be carried out during the day. Each line requires a certain setting for the amplifier to be used in conjunction with it for "equalising" - that is, for correcting the line characteristics for frequency response. These values have been predetermined after tests carried out by the "Lines Department" engineers. When all is in order the "music" circuit is plugged over to the control position which will require the O.B, whilst the "control" or speaking circuit is plugged up to the supervisory position concerned. The lines termination engineers also deal with all tests and defects on trunk lines. They are the Control Room's linkage with the G.P.O. whether it be Welbeck Exchange for London O.B.s, Trunks for S.B.s, long distance O.B.s and Continental work or Radio Terminal for transmission with New York, Australia, ships at sea and in fact any Post Office radio link.
Another section of engineers is responsible for testing the microphones in the studios. About half an hour before the commencement of every transmission or rehearsal the microphones are listened to through the normal chain of amplifiers, polarising feeds are checked and a very rigid routine is carried out to ensure that even with abnormal usage no technical fault is apparent. It must be remembered that the microphone - being the first link in the chain, and requiring as it does a considerable amount of amplification to bring its signal strength to within control limits - must of necessity be absolutely free from the most minute defects if good transmission is to be obtained. The reason that microphone tests are carried out about half an hour before the microphones come into use is to ensure that they are in good order up to the latest time which is practicable, while also allowing a short time to remedy any defects which may be found. Were microphone circuits to be tested some hours in advance there would always be the possibility of a defect developing after the test.
It falls to the lot of these engineers also to prepare the circuits for all rehearsals which may be required. On an average there are about eight separate rehearsals being carried out at the same time between the hours of 10 a.m. and 6 p.m. (excluding the 1 p.m. to 2 p.m. period) and during a normal day as many as 30 to 40 individual rehearsals dealt with, each requiring the microphones and associated equipment energised exactly as if it were a transmission. This entails setting up the correct amplifier circuits so that the rehearsal may be listened to on loudspeakers wherever required, and in certain cases the "talk-back" facilities need setting up to suit the particular conditions of studio, listening point, etc., whereby the person listening to the rehearsal may speak over a microphone circuit and by means of a loudspeaker give instructions to those rehearsing in the studio.
Rather similar to the work described above, but very much more complicated, is the preparation of the circuits for dramatic productions using many studios. As will have been gathered from the article on "The Dramatic Control Panels" on p.385 of the 1933 Year-Book, the possible combinations of circuits are endless. The normal lay-out requires usually some three studios, together with echo on perhaps two of them, an effects and a gramophone studio - in all some seven sources of "programme." All these have to be plugged up to the correct positions on the panel as indicated by the producer. Cue light circuits, loudspeakers in listening rooms, headphone circuits, talk-back circuits to loudspeakers in the studios in the case of rehearsals, and probably circuits for recording purposes have to be set up and thoroughly tested before the producer can start his rehearsal. Such an intricate linkage requires the most
In addition to those already mentioned, there are the engineers sitting at the supervisory positions dealing with the internal telephonic inter-communication and the engineers checking the transmission quality by loudspeaker three floors below, and the senior control room engineer who is the mainspring of the whole section of engineers.
But this is not the whole of the picture. Side by side with what might be called the main engineering routine there is the work at the Blattnerphone recording apparatus (now largely used for Empire Broadcasting as well as for rehearsal purposes), that connected with gramophone recording, running the television transmissions, and the ultra short-wave transmitter, not to mention the labour of maintaining and cleaning this vast amount of apparatus and wiring, the storage and issue of spare parts, and the testing of the valves actually in circuit (it takes one man a month to do them all).
Finally, there are the engineers responsible for broadcasting the programmes to the Empire throughout the night, and who in their spare time carry out most rigid tests on the loudspeakers which are used in the various listening rooms and studios, in order to maintain a high standard of quality of reproduction.
Add to all this the work entailed in testing out new types of microphones,
Dramatic Control Rooms
The two dramatic control rooms - No.1, above and left, and No.2, below. The desk was framed up in stream-lined tubular steel sections, supported and fixed to the floor at one end by two free standing legs. At the other end the legs were enclosed to form a duct for the cabling which rose from a floor duct. The panel enclosure and table were in mahogany laminwood and cellulosed a lavender grey. The walls were acoustically treated with half-inch insulwood building board.
The two rooms took their place in the transmission chain between the studios and the main Control Room.
The same room could be used for both rehearsals and transmissions. They enabled the mixing of up to eleven studios for one transmission. In this way, it was said, stage management was facilitated in the studios and a completely mixed programme was passed on to the Control Room for distribution to the transmitters.
The 1933 BBC Year Book explained: "The object of the D.C. Panel is to enable the producer to combine at will the output from various studios. This is necessary,
Standing a little to the left of the southern entrance to the Control Room gave this view, left, of the corridor leading to the two studios on the eighth floor. The circular sign to 8B is on the wall between the two flights of stairs. The corridor was lower than most due to pipework and conduits above. Head room was maintained with the use of lights flush to the ceiling. The walls were pale yellow and the floor was a cream coloured composition.
Going up the second flight of stairs led to the outer doors of Studio 8A, right. The inner studio doors are ahead and to the left another door led to the listening and silence rooms. The vase-like object is an unspillable ash container. It was made from bronze, the upper half was satin-silvered and the lower part of the weighted base had a gunmetal finish. Turning the knob released the lower part for cleaning.
Left - Looking north through the opened inner doors.
8A was designed by Serge Chermayeff. It was used for small orchestras, brass and military bands, musical comedy and revues. Because of the sloping mansard roof on the east side of BH it was not possible to build the studio tower to the eighth floor level and 8A was therefore positioned right over to the west wall of the building which allowed some circular windows to admit daylight - the only studio in the building where natural light penetrated.
The studio was 51' x 33' x 16' high, a volume of 27,000 cu. ft. The reverberation time was 1.1 seconds.
The colour view below is looking northwards from the door and the shot below it was taken from the other end.
The walls had a protective birch plywood dado to the height of five feet. The ebonized skirting was removable to allow access to the microphone cables within - this feature was used in all the studios. The bands above the dado were covered with untreated building board the edges of which were protected by aluminium strips. The ceiling was painted in an apparently haphazard pattern. The doors were faced with oak ply painted bright green with polished aluminium fittings. The floor was laid with square cork tiles in five shades ranging from light buff to black, again in a random design. A large circle in the design suggested a grouping area for the musicians.
Artificial light came from wall boxes which also covered the circular windows on the west side. Long strip lights were mounted on the circular ventilation pans on the ceiling.
Chromium-plated tubular steel-framed settees covered in striped coral pink tweed were designed by Chermayeff as was the conductor's rostrum.
left - The south entrance doors. A microphone socket can be seen mounted on the skirting and on the panel above a socket for headphones.
right - A curving corner showing how the bands of material of different widths were run unbroken round the walls, an effect emphasised by the protective metal strips.
right - Above the listening room window on the south wall, the three feet diameter clock face was of polished stainless steel; the hands were matt black. The hour markings were applied anodized copper and minute ones were engraved and filled with wax.
left - The Listening Room for Studio 8A. The mixer handled three sources - the single microphone that 8A could employ, plus two gramophone points.
Through the open door can be seen the Silence Room, where announcements could be made during an interval in the studio.
8A was the first studio to be completed and the first musical broadcast from BH came from there. It was on 15th March 1932 and featured Henry Hall and the
newly formed fourteen piece BBC Dance Orchestra. The 1933 BBC Year Book commented that "the opening broadcast took place in not very favourable circumstances. It was from the then unused studio 8A…which had been designed, and is now used, for quite different musical combinations…The first broadcast brought in something under a thousand letters, and though many contained suggestions and criticisms of detail, the majority were definitely appreciative."
Like the studio, the band room had a protective dado of birch plywood. The benches were of ebonized wood covered with standardized removable cushions covered in black and grey tweed cushions. The composition floor was red.
8B was also designed by Serge Chermayeff. It was furnished as a comfortable room in a private house. A microphone was concealed above a false fireplace so that discussions could take place round the fire, 'without any microphone consciousness on the part of the participants.' For more formal discussions, a microphone was provided at the centre of a horse-shoe table.
The tall artificial window gave a sense of airiness and the 'fire' threw a pleasant glow over the floor and lit up the satin copper colour of the metalwork and skirting. A natural wool rug covered much of the floor.
8B was 16' x 13' x 10' high, a volume of 2,100 cu. ft. The reverberation time was 0.45 seconds.
Again the work of Chermayeff, the waiting room had floor and skirting covered with small square tiles arranged in a carpet-like pattern. The settee cushions and the armchair upholstery were tweed. Lighting was
Ladies' Dressing Room
This was an oddly shaped room with intruding beams and casings. The photo, left, shows a radiator cover, the dressing table and a mirror.
above - The circle in the inlaid rubber floor was white, the surround was pink-grey with accents of red. The settee was covered with coral red fabric and the walls were cream-white.