Royal Navy: Eerie nuclear siren blares from Portsmouth Naval Base as video captures emergency alarm

The alarm was raised at HMNB Portsmouth at 9.30am this morning (June 25). A safety alert was made over the intercom before the siren started - heard blaring in streets surrounding the naval base.

This was carried out as part of statutory routine tests which are part of the Royal Navy’s nuclear accident response plan. Regulations from Portsmouth City Council and Gosport Borough Council outline when they are conducted and the safety plan around them. This is outlined in the local authorities’ nuclear safety programme.

A statement from HMNB Portsmouth published yesterday said: “Please note there will be a full test of the Naval Base’s nuclear emergency alerting siren at 9.30am tomorrow (June 25) which may be able to be heard outside of the base.

“It is a statutory requirement to test the alarm three times a year and this test is being conducted in agreement with Portsmouth and Gosport local authorities. The two-tone siren will be sounded for one minute for the test.”

Sirens are sounded three times a year. The routine and regular procedures are carried out by the Royal Navy on the last Wednesday of February, June and October.