MOD Plymouth, MOD Skipness & MOD Portsmouth Fort Blockhouse

Site locations Plymouth Range area map

The Devonport site is located in Plymouth, Devon in the southwest of England. The site provides electromagnetic ranging of ships and submarines and a harbour entrance range. It is split over three facilities:

  • HM Naval Base Devonport – Main Office
  • Eastern Kings – Harbour Entrance Range (HER)
  • Pier Cellars – Electromagnetic 20m Open Sea Range

Portsmouth HER is an unmanned facility located within Fort Blockhouse, Haslar Road, Gosport. It automatically gathers magnetic signatures of vessels entering and leaving Portsmouth Harbour.

The Skipness ESM Calibration Facility is just north of Skipness Point, Scotland, in position 055º 46.75’ North 005º 19.05’ West. The deep water between the Kintyre peninsula and the isle of Arran are dedicated trials areas for both submarines and surface ships. Skipness is an unmanned site except for maintenance and trials.

The Skipness site provides Radar stimulation for submarine and surface Electronic Support Measures (ESM) equipment. The EW calibration facility aims a calibrated radar signal at the vessel, enabling the vessel’s onboard ESM system to detect and measure the signal, and hence check and recalibrate its systems.


  • Instrumented Maritime Range Services
  • Operational Signature Services
  • Test & Evaluation Services