The Suffolk Stop Lines and Vulnerable Points
- The strategy of Ironside also involved the building of a series of defended stop lines to delay the enemy sufficiently for reserves to be brought up to counter attack.
- The first line of defence was to be the defended coastline with a further series of lines being built inland culminating in the General Head Quarters (GHQ) Line defending London and the industrial Midlands.
- Where possible natural obstructions, such as waterways, were used but where these were not present it was necessary to build artificial anti-tank ditches and other obstacles that were often defended by pillboxes.
East Anglian Stop Lines (Dobinson, 1996)
- A number of stop lines were built across East Anglia. Two parts of the Eastern Command line ran across Suffolk. The western line was heavily defended with pillboxes and anti-tank gun emplacments, while the eastern line made more use of natural anti-tank features and may have been rushed in construction.
- Walberswick itself was the termination point of one part of 11 Corps' 'B' line that originated in King's Lynn in Norfolk. Also relevant to Walberswick was the 'Back Line', which followed the line of road and railway between Ipswich and Halesworth, running between four to ten miles behind the beaches.
- In July 1940 it was reported that one company of the 2ndBattalion Kensington Regiment formed part of divisional reserve and were to move to 'previously recced positions to hold the enemy on the line until reinforcements arrive from the rear', almost certainly a reference to the Back Line.
- The back line was considerably strengthened in 1941 and, while it is difficult to know precisely what had actually been constructed in 1940, the course of the line and its potential for defence had certainly been established.
- Together with the coastal crust and the construction of Stop Lines certain areas were designated as Vunerable Points (VPs) and given priority for defence. VPs were installations of strategic importance with those of the first category including radar stations, airfields, ports, and explosive dumps.
- Lower category VPs would have included power stations, waterworks and pumping stations and telephone exchanges. All of these would require a permanent military guard, the number of men required depending on its position and importance.