Nelson struck a magnetic mine in 1939 and remained at Portsmouth for repairs until August 1940. Major work was still possible there early in the war, though enemy air power was making Britain's large yards increasingly dangerous. An immobilized capital ship offered bombers a target that could neither maneuver nor disperse. That danger soon pushed more damaged ships toward overseas yards.
Notable Point · 24:27-24:59
Portsmouth can still repair Nelson early in the war
A 1939 magnetic-mine detonation keeps Nelson at Portsmouth until August 1940, near the limit of what the threatened yard can safely support.