If this thread were in A H & N it might get more replies.
Carnaby of course was one of the three airfields re-constructed specifically as 'emergency' runways, the other two being Woodbridge and Manston.
I think the spec was 9000ft x 450ft giving 3 parallel strips of 150ft (ie the 'normal' width of a runway) x 3000yds, so that if a strip was blocked by a crashed aircraft, the adjacent one could be used. The loop taxiways adjacent to the runway and still visible at Woodbridge were constructed for the wreckage to be deposited there by means of bulldozers.