Vulnerable Points

Vulnerable Points (VP’s) were facilities essential for the defence of Britain that needed a permanent guard and included aerodromes, ports, fuel depots etc. The front line Division in Suffolk was operationally responsible for VP’s. The actual administration and training of non divisional troops (e.g Home Defence Battalions) guarding VP’s was the responsibility of East Anglian Area but Divisional sub-sector commanders were to insure that adequate schemes for their protection existed.


The following is a list of VP’s (with serial number) that 55th Division was operationally responsible for in May 1940:

  • C1 Duxford Aerodrome

  • S4 Wattisham Aerodrome

  • S5 Bawdsey R.D.F Station

  • S7 Darsham R.D.F Station

  • S8 Claydon AV Fuel Depot

  • S9 Felixstowe Admiralty Oil Depot

  • S9(a) Felixstowe T.B.D. Guard

  • S12 Ipswich Dock F.S. Guard

  • S14 Martlesham Aerodrome

  • S15 Dunwich R.D.F Station

  • S16 Harwich Train Ferry Guard

  • S1 Stradishall Aerodrome


By 1941, Vulnerable points were classified as follows:

  • V.1 Embarkation Ports, Docks and Harbors

  • V.3 Military Factories, Stores, Magazines, electric plants

  • V.4 RAF Establishments (not including Aerodromes or Experimental Stations)

  • V.6 (a) Navy and Military wireless stations, (b) Post Office, Cable and Wireless Ltd, commercial cable companies (c)      Telecommunications

  • V.7 BBC and civil wireless stations

  • V.8 Road and railway communications

  • V.9 Admiralty establishments, ammunition sidings, oil fuel installations, depots

  • V.10 Commercial oil fuel installations

  • V.13 Private Factories

  • V.15 Interment camps

  • V.16 Prisoner of War Camps

  • V.17 Water Works, land drainage

  • V.18 Electricity and Gas Undertakings

  • V.19 Explosive stores, Mines Department

  • V.20 Miscellaneous


Although Aerodromes and RAF Experimental Stations were not included within this classification they were of course guarded and often listed as a VP in Divisional / Brigade Defence Schemes. For example, Bawdsey Air Ministry Experimental Station was guarded by Field Forces in beach defences. Defences included a ring of pillboxes, anti-tank blocks and LAA posts.





















Left: Purpose built structure, with LAA structure on roof, Bawdsey Experimental Station

Middle: Purpose built structure, Bawdsey Experimental Station

Right: Type 22 Pillbox, Bawdsey Experimental Station


Vulnerable Points were classified in terms of priority (1 – 4, Military and Unclassified) and as a rule Guards were found according to priority as follows:


P.1  - Military Guards other than Field Forces

P.2  - Corps of Military Police

P.3 -  Civil Police

P.4  - Home Guard

Military  - At discretion of military commander concerned



The local battalion Commander was ultimately responsible for the defence of all VP’s in his area. Guards were not to be assigned a mobile role.


Radar instillations were provided with defences including pillboxes and obstacles (such as wire, anti-tank cubes).  Guards were usually Home Defence units  - for example Darsham RDF was guarded by two officers and 60 other ranks of ‘C’ Coy (Home Defence) Suffolk Regt as well as one troop of 84 LAA  Battery. Arrangements were also made to evacuate highly skilled technical personnel. For example at Dunwich RDF, arrangements were made with No 74 (Sigs.) Wing R.A.F, Cambridge, to evacuate 15 personnel where there is likelihood of the installation being destroyed by enemy action.  Such orders would be given by the local commander, in consultation with the Installation commander and the personnel would be evacuated to Yoxford and then to a location in the rear determined by Eastern Command as soon as possible. Field Forces also made arrangements to provide immediate relief columns.





















Above: One of six pillboxes, Darsham RDF. Metal plates on roof were probably  protection for LAA gun.


An example of a Civil VP was Richard Garret Engineering Works, Leiston (Priority 4). The responsibility for defence of this VP was the local Home Guard, many being employees of the Works.


Felixstowe Docks (V.1, Priority 3) was guarded by the Dock Police but was backed up with a platoon of Field Forces in a beach defence role.


An example of an Unclassified VP (as at 1941) was L.N.E.R Ipswich:-  (a) Control Office and Telephone Exchange, (b) Locomotive Sheds (c) Tunnel.



45 Brigade papers, TNA

46 Brigade papers, TNA

55 Division papers, TNA


Pillbox, Bawdsey Manor Strong point, Bawdsey Manor Type 22, Bawdsey Manor TM406716(2) Interior of second pillbox (1)