The school bell has been in place since before living memory. It is mentioned in the Log Book twice - the first time is possibly a mystery
“small bell fitted on top of the girls’ lobby”
Is this the same bell?
The second entry is more definite -

"Oct 30th 1980
School bell rung for first time since World War11 When it was discontinued by Government regulations. Pupil Anthny Rogers won a draw to be first to ring the bell at 8.55am at the start of school"
We do not use the bell now, but it is still in working order.
This is Mr Sid Adams talking about when the bell was used
Press play on the tool bar below to listen to the school bell