These two views show the control room in its original form - no add-on boxes yet! In the foreground in the above picture is the Assistant Technical Operations Manager's desk. Beyond that is the 'front bench' and above it the routing display.
At the right of the front bench is the Simultaneous Broadcast (SB) position. This was the main point of contact with regional centres and transmitters. The keys of the continuity interchange are on the far right and the engineering manual exchange (EMX) is on the left. Monitoring buttons and the all important control room intercom take up most of the remaining panels.
Next comes the miscellaneous switching position (MSP). The large bank of bridged silver locking keys were used to drive the selectors feeding outgoing lines, frequently used outside sources and recording channels. A common marking panel is below - the second one is a spare. You would punch out the code, grasp the silver key and locate the appropriate indicator on the main display above. A quick check to make sure you had the right key and then a momentary flick down to drive the selector. If the indicator you were watching didn't change you were probably in trouble!
Next, surrounded by monitoring buttons comes the main EMX. When studios rang the control room this was generally where their call appeared. Selector alarms are round to the far left. Should a selector fail to stop, someone would have to dash down to the selector room and remove its power supply. At this time the large PPMs carried "slugged" displays of Home, Light , Third and TV sound.