It is not known when this logo was first used. However when the school re-opened in 1947 it was imprinted on white bedspreads which covered the boys beds. This was a one-day outing for the covers - how strange. Perhaps it was to impress the mothers who had come to leave their boys there. It is thought that the design, and the covers, might date back to the opening of the school in 1922.
It appeared on stationery and the the intertwined letters were sewn onto school caps into the 1960's as illustrated below.