MOD Portland Bill

Location of Portland Range Aerial view of Portland Range

The Portland Bill site is on the Isle of Portland in Dorset. The site was chosen in the 1960s for magnetic measurement because of its magnetic cleanliness. Portland stone is non-magnetic and because the site is remote from any magnetic disturbance such as heavy traffic, very small magnetic fields from equipment can be measured with absolute certainty. The site is used to magnetically assess any item, but mainly MCMV and EOD equipment. Magnetic compasses can also be tested.

This unique facility is notified and approved by the Maritime and Coastguard Agency and is the only accredited centre for Type Approval of Magnetic Compasses and Binnacles in the UK.

The site is capable of simulating the Earth’s magnetic field at any point, and measuring the effect on the test object. The Earth’s field can be manipulated to zero, or be broken into its vertical and horizontal components.

This magnetically controlled environment is suitable for:

We also provide consultancy, training and data services.


  • Electronic Warfare Calibration
  • EOD Tools & Diving Equipment Magnetic Assessment Services
  • Instrumented Maritime Range Services
  • Magnetic Compass Calibration Services
  • Operational Signature Services
  • Test & Evaluation Services