Tripartite Education:

The 1944 Butler Education Act established the Tripartite System of Education, and under it, the Dinnington Secondary School became a Secondary Modern School. In the West Riding this change was largely cosmetic. There was certainly no appetite for an 11+ system, and so Dinnington maintained the locally well-established 13+ programme. Entrance exams for Maltby Grammar, the Technical College (next door), and other establishments continued to be sat in the second year, leading to an exodus of students (mainly to the Tech) and a diminished population in the third (and final) year.

Potato Picking:

Potato picking was an annual nuisance to the timetable. The first reference to it in the Log Books comes in October 1944, when the attendance in the Boys' Department was as low as 40%. Boys were allowed out in the fields if the had prior permission in the form of a blue card. Those without blue cards were sent back to school. In 1951, the decision was made to lengthen the Summer Holiday by a fortnight to avoid the potato disruption. Meanwhile, the Head of the Girls' Department, Mrs Goldthorpe, constantly refused girls to go potato picking, and was pleased to observe that by October 1952 the practice had completely died out.

Overcrowding and Expansion:

In August 1946, the catchment area was extended to Kiveton and Wales. A third of pupils were bussed to the school. In 1947, the compulsory school leaving age was raised to 15, and this (confounded further by the emergent baby-boom in the next decade) led to an increasing shortage of teaching space.

By October 1950, Dinnington was one of only two segregated schools in the Rother Valley Divisional Executive, with the other being Maltby. Academic standards were not particularly high, not least through oversubscription and understaffing. The Halls were being used for teaching, and there were up to 40 pupils per form. Between 1948-1956 there were 16 appointments to the permanent staff of the Boys' school and 51 temporary teachers, during a severe staffing crisis considered so bad that the HM Inspectorate felt in necessary to postpone their visit to the school.

To address the overcrowding problem, Throapham Manor was commandeered, along with parts of the Nursery and Junior Mixed schools, and a small handful of prefabs had been put up in the late '40s (about six or seven, lining the east side of Manor Lane). Towards the end of 1952, foundations were laid at the back of the school for a pair of West Riding Classroom blocks (sometimes nicknamed HENGIST classrooms as a play on the government's HORSA (Hutting Operation for the Raising of the School Leaving Age) pre-fab classroom scheme of the previous decade): prefab erections made from the West Riding LEA's in-house building system. The new buildings were up by the start of 1954. While this addition alleviated some of the pressure, by August 1955 the Girls' Head, Mrs Goldthorpe, described the school as "grossly overcrowded". By 1956, the population was almost double that on opening, while the school had only increased its accommodation by about a third.

Academic Innovation:

Mining was an attractive career choice for many pupils, mainly for the relatively high wages and the National Service exemption. Perhaps in an effort to broaden the horizons of the more academically minded Modern student, the Boys' Department, now under Mr Spelman, instituted the first final leaving exams at the school in 1953 (initially in English, Maths, Geography, History and Science, with Art, Metalwork, Woodwork and Music coming a year later), based on papers set by the College of Preceptors. Inter-House competition was formalised and expanded under Spelman, and a uniform was introduced for new boys in 1955; the Head having previously noted that pupils were "badly turned out and many arrive in rags". In June 1956, for the first time at Dinnington, a select group of four boys sat the College of Preceptors' exams in English (Language & Literature), Art, Maths, Geography, General Science, Woodwork, Metalwork and Technical Drawing. Two candidates passed in five subjects and the other two in four.