The site was a once a temporary medical care centre, set up in 1938 in case of bombing casualties in the area, including Middlesbrough and Stockton-on-Tees.

These were prepared for casualties of expected bombing runs over areas near ports and industry on the River Tees, though initially, the hospital housed evacuated wounded service personnel from Dunkirk.

New ambulance bays needed to be constructed and more accommodation blocks were required to house 200 staff, besides the initial 200 beds for injured personnel.

This was an ambulance (a Humber Utility Van), with an anaesthetist, a surgeon, a resuscitation officer, a theatre sister and an operating room assistant.

[11] The MSU also performed surgery at various airfield station sick quarters when it was considered inadvisable to move the patient to the hospital.

In 1940, a training regime was implemented and by 1943, the RCAF medical branch had nurses at Warrington, Bournemouth, East Grinstead and Northallerton.

[24] Many of the wooden huts at the hospital, which were constructed from Canadian Oregon and Cedar Pine, remained on site until 1999, when they were finally demolished.