I'm sure that recommendations are that if you are to offer an on-call service then there should be 3 people in it.
I've also done 1 in 2 and it quickly began to erode my enthusiasm for the job being called out multiple times a week to deal with the acute service of ferrying machines around a large hospital as nursing staff refused to be involved.
The department was made up of a technical manager (B7) and 3 B6 techs. We had around 200 machines in-centre and about 60 in the community and 7 water plants. On-call when fully staffed was 1 in 4 and you had to work a Saturday. The acute service ran 24/7 365.
Agenda for change seemed to screw up a lot of the roles it was supposed to harmonize meaning the working grade for a tech could be a 6 or a 7 depending on where you worked.
Ian Wilde