A huge WWII sea mine was spotted at a West Sussex beach yesterday. The weapon was reported to the Police and subsequently identified as a German aerial mine.

A Royal Navy explosive ordnance disposal team arrived from Portsmouth to deal with the unexploded ordnance (UXO). A special float was attached to the weapon, allowing it to be towed out to deeper water for disposal. 

Click here for a news article covering the story.

WWII sea mine explosion Sussex
The mine was detonated using small explosive charges
What type of WWII sea mine was it?

The long cylindrical weapon looked more like a bomb than a WWII sea mine; a typically spherical design. The reason for this is in its method of delivery. The mine was actually designed to be dropped from an aircraft, rather than pushed off the back of a warship.

The weapon in question appears to have been an air-delivered LMB magnetic influence mine. It would have weighed approximately 2,116 lbs (960 kg),  1,554 lbs of which is high explosive charge, a huge warhead.

Mines such as this represent the largest German explosive hazard still encountered in Britain today.

WWII sea mine LMB
A Luftwaffe LMB mine with tail fin assembly

The magnetic influence mine was state of the art during WWII. The German military were world leaders in this field at the time. Only after reverse engineering an unexploded LMB mine, did the British gain the same technology.

Is the mine still dangerous?

German LMB mines used electric fuses, which required a battery. Consequently, they can no longer function as the battery would have died many years ago. As with all UXO however, the explosives can still be initiated by mechanical impact or fire.

Remember, if you ever find a suspicious looking object on a beach, do not touch it, just ring the Police or Coast Guard immediately.

Does UXO pose a risk to marine engineering?

Some of the most concentrated areas of UXO contamination can be found in our oceans. Brimstone work in partnership with CDMS Diving to offer UXO risk mitigation services in marine environments. Click here for more details.