By co-incidence, I’m reading Leo McKinstry’s latest: Sealion. This book covers the events of 1940 and in particular those relating to an actual invasion and the home airfields directly in the firing line.

After Dunkirk, speedy re-armament was the order of the day giving rise to many cost effective solutions including the McNaughton tubes. These tubes gave impressive results upon detonation. They could re-arrange the contours of the ground most effectively, instantly creating anti tank ditches and earthworks impassable to wheeled and most tracked vehicles.