Around 20 per class, seperate doors for each class, and when the doors open they all just go in - no lining up or anything. So they can all be in the door within a minute
I assume that with that system with such a short entrance time, the children in the playground get some sort of signal/whistle/bell to warn them a minute or two before to let them know that the door is about to open? Otherwise it's impossible for all the kids to notice the door is open, get their bag and get inside in less than 60 seconds.
When I was at school we had 25/30 in a year and all primary classrooms had a classroom door directly into the playground via the class cloakroom as well as one into the internal corridor. The outer doors automatically locked on closing, and can only be opened by the teacher's swipe card and the inner door could only be accessed if you were inside the building. The school gates opened at 8:30 for general drop off and we had to be lined up at our door at 8:40, when the teacher would let us in, so we got a warning bell at 8:39 that told us it was a minute to walk in time. Anyone that arrived after 8:40 would be late, but we all knew that if you weren't in the playground by the warning bell, you would be late and sent to the office to sign in.
Even if you got to the door as it was closing, you'd have to go to the office because the teacher would open the door, and then as the students came into the cloakroom the teacher would walk back through to the classroom to supervise as students came in and got settled at their desks etc ... they couldn't keep to-ing and fro-ing to swipe the door open for every student who was late.
It is a small school ... By the time I got round to the office and signed him in it was nearly 9. It just seems so uptight for primary school children - and not fair to make him more late for the sake of 60 seconds.
It's not about being "uptight" it's about safeguarding ... the doors close at a certain time and anyone not in the classroom at that point is officially late and not signed in under the teacher's care, and a record was required to show that the student was then signed in late, at the office, where all the records are kept.
"Nearly 9" ... now is that 8:56 or 8:59? it's rather vague for someone complaining about being one minute late ... Either way it's your fault he was one minute late for normal going in time, and therefore it's your responsibility to get him properly signed in, even if that then makes him five or eight minutes late in total.