Thanks to Port Talbot diver and historian Steve Jones, the Milford Haven Waterway has given up one of its military secrets, which visitors to Pembroke Dock Heritage Centre can now see in a unique display.

When diving in the Haven, Steve recovered the very heavy nose and tail cones of the impressive projectile fired from an experimental Zalinski Dynamite Gun, located at Dale Fort - one of the many local Victorian fortifications.

These are now on view at the Heritage Centre. A central section, which would have been packed with explosive, is represented by a gas cylinder, conveniently of similar 15 inch diameter dimensions. And Steve has replicated a long wooden tail which helped stabilise the projectile in flight.

The massive Zalinski gun - operated by compressed air - was purchased from America by the British government in the 1890s and was originally installed at Shoeburyness, Essex. When fired it was said to have been heard 30 miles away so was moved to Dale - where local communities were then subjected to similar noise levels!

In 1893 trials began locally, the gun was fired and successfully destroyed an old steam paddle gunboat, HMS Harpy. However, it was decided that the system was too complicated and the gun was returned to the United States, its Pembrokeshire connections forgotten until Steve Jones dived in the Haven.

Open Monday to Friday, 10am to 4pm, Pembroke Dock Heritage Centre is an all-weather family attraction in the heart of Wales’ only Royal Dockyard.

Tickets are now on sale at the Heritage Centre for a 1940s Big Band Night with the Phil Dando Big Band at the Royal Dockyard’s Pembroke Port Pavilion, on June 21 to celebrate the 80th anniversaries of VJ and VE Day. With doors opening at 6pm and the band starting at 8pm, the event is sponsored by the Port of Milford Haven.