Grenades consisted of a hollow iron casing filled with gunpowder, and bullets were ignited by a fuse that passed through the casing. (Image: Robert Felce) "KDSPs "Ancient grenades and cannons recovered from the wreckage of an old pirate ship have been found off the coast of Cornwall, England, "KDSPE""KDSPs "Divers have recovered items from the SeiDAM wreck, pieces of which sank from the coast in 1684 after recent storms disturbed the sand that once covered the seabed,

Additionally, two 17th-century hand grenades, each consisting of a hollow iron casing filled with gunpowder, were found near the wreck after it washed ashore. [See photos of pirate ship, grenades and other artifacts]

The second of the two grenades, discovered by local historian Robert Fellows in late November on a beach near the Dollar Cove Schiedam shipwreck site,

located in the Gonvallo area of the Lizard Peninsula on the coast of Cornwall, is an ancient, crusted grenade that was recovered from a 17th century shipwreck filled with munitions that was washed away. (Robert Felce)

Felce told Live Science that he regularly visits the beach, which is exposed to the strong waves of the Atlantic Ocean, and that several artifacts have washed up on the beach over the years - he found a similar grenade on the same beach last year.

Both objects were heavily encrusted more than 300 years ago after lying on the bottom of the ocean for much longer, said Fellows, who initially thought the latest grenade was an ordinary rock before he slipped, fell to the ground, and the grenade cracked open, revealing the two halves of the metal weapon and the explosives inside.

Although the gunpowder in the grenade was damp and centuries old, he reported the discovery to the local police, who brought in bomb disposal experts from the British Army to make sure the disposal was safe.

Fellows said the curtains in his peaceful seaside village of Mourion were "twitching" when the bomb disposal vehicle arrived at his house with a flashing blue light; the army experts quickly scraped the grenade free of its ancient gunpowder, rendering the grenade safe.

On board the pirate ship

Barbara Pirate

in 1683, the Dutch merchant ship

Barbara Pirate

captured the Dutch merchant ship Barbara Pirate, which had been in service for many years. captured the Dutch merchant ship "Schiedam" as a prize. The ship was then seized by the Royal Navy, which used it to transport stores until it sank in April 1684 in a storm near Dollar Cove. [The most notorious pirate of all time]

Historian Robert Fellows finds artifacts from the 17th-century shipwreck of the Hidan at Dollar Cove in Cornwall. (Robert Fellows)

The Shidan was sinking while delivering munitions from a British garrison returning from the Moroccan city of Tangier. The stores contained boxes of grenades, like the ones washed at Dollar Cove.

Felce, who is the author of A Few Histories of the Cornish Coast, says that the exploding grenades were some of the earliest of their kind, and that later on, the British Army was specially trained to throw them over great distances.

, Such units made up the first British bomb-throwing regiments, a designation still used by some British army regiments, and Fellows said the grenades were detonated by igniting gunpowder through a tubular fuse that passed through the casing.

"They may have been used to frighten people, but they were certainly meant to kill the enemy," Fellows said I'd like to know more about where and how they were constructed as it relates to early engineering and metallurgy.

Sea storms

Recent storms have disturbed the sand on the Schiedam wreckage, revealing several cannons and other debris still lying on the seafloor.

The wreck site was rediscovered off the coast about two years ago by two divers from the Cornish Marine Archaeology Private Research Group, which observes several shipwreck proxies off the Cornish coast on behalf of Historic England.

The former pirate ship "Schiedam" was wre 1684 in a storm beside Dollar Bay in Cornwall. (Robert Fellows)

One of the divers, Mark Milburn, told Live Science that they returned to the wreck site on the seafloor in recent weeks, where they discovered that the sand had shifted during the recent storms and found more wreckage.

He said the artifacts from the Hidan wreck that have been documented so far include 11 cannons,

Milburn said his colleague, diver and author David Gibbins, has photographed some of the cannons and the few remaining pieces of wood from the wreckage as 3-D photogrammetric models. They can be seen on his website.

"There's very little wood structure left," Milburn said of the damage that occurs every time it's exposed. ...We will continue to monitor the site, [and] we have the right to retrieve any artifacts that we believe are at risk."

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Originally published in Live Science