"This was not a viewing room but was the room containing 5000?? gallon tanks."

"The room was rather like a swimming pool with no water. The raised walkway all around the outside of the 'pool' was just that - a walkway for inspection."

"The tanks/pipes/pumps etc. were all sited in the body of the floor and you looked down on them from the walkway."

"As you look at your photograph, you will see a set of steps in the far corner which allowed one to go down into the tank area. The door immediately behind this set of steps (just visible) was the laboratory where I worked."

"I also recall that we had the services of an elderly civilian whose job it was to keep this whole room clean. I can see him now sitting down with a cup of tea, a cleaning rag in his hand and a mop and bucket by his side." - George