Post War Calshot Castle
At the end of the Second World War, Calshot Castle returned to duty as an active air base, housing two squadrons of Sunderland flying boats which took part in the Berlin airlift of 1948, before being passed across to Maintenance Command in 1953. The Southampton Harbour Board built a coastguard lookout tower at the castle in 1952, and the following year they began to construct a signal station tower on top of the keep, complete with radar and radio facilities, which opened in 1958. From 1954 – 1967 the area outside the castle was used to store two of the three Saunders-Roe Princess Flying Boats that were prototypes from an abandoned project to build the largest all-metal flying boat, in fact, one of the largest aircraft ever conceived at the time (You can read more about these planes here) .
The RAF station at Calshot was finally closed in 1961.
Hampshire County Council leased the site from the Crown Estates in 1964; the castle itself passed into the guardianship of the state, with the hangars being used as an activity centre which is still the case today. A Royal National Lifeboat Institution station opened in 1971 alongside the castle, with a 130-foot (40 m)-tall replacement coastguard tower constructed two years later.
English Heritage took over management of the castle in 1983, and stripped back 20th-century additions to present it as it might have appeared in 1914, including demolishing the old signal station tower.
However this film from British Pathe of Southampton Radar in 1960 shows the castle as it was in 1960.
FILM ID:101.04
Summary: Radar station at Calshot, Southampton alerts a dredger to clear the way for the SS America.
Description: M/S of the entrance of a radar station housed in a castle in Calshot, Southampton as a sailor walks through the stone archway. C/Us of a slit window and a round ornament on the castle wall. M/S of the castle (the commentator says it was built in Henry VIII’s time), tilt up to show a modern building on top of it and the radar scanner whirling round above it. L/S of radar station on the edge of the harbour, with a two of the Princess flying boats parked behind it. L/S of the Southampton estuary, with the SS America steaming through towards us.