I'm not so sure that they were spittoons as such. The way that the pool systems works was that they had an overflow channel going all of the way around the pool where the water would go down to the filters, cleaned out and then back into the pool. It certainly was a very old fashioned design.I remember using the swimming baths whilst at Edgbaston High until they built their own, so must have been between about 1962-64. They were tiled, in not very good state of repair, with "bridges" across so that the deaf pupils could lip read the teachers and there were spittoons at the side.