A 650-year-old ship cannon discovered off the Swedish coast

The Marstrand cannon. Image credit: Bo Niklasson / Bohusläns Museum.

Present data concerning the introduction of shipboard artillery in Europe is proscribed. Nonetheless, a small muzzle-loadable solid copper alloy cannon discovered off Marstrand on the west coast of Sweden could present some vital leads concerning this improvement. The cannon dates again to the fourteenth century AD, and is believed to have come from a shipwreck.

Marstrand cannon.  Image source: Bo Niklasson / Bohuslan Museum.

Marstrand cannon. Picture supply: Bo Niklasson / Bohuslan Museum.

In the summertime of 2001, a small, ancient-looking cannon was discovered within the open sea, about 5 kilometers southwest of Marstrand Island on the west coast of Sweden.

It was situated on the foot of the big Hanihakarna shoal, partially buried in sediments at a water depth of about 20 metres.

The discoverer, an area diver who initially didn’t perceive what he had discovered, managed to convey the heavy object to the floor.

A while later, after realizing the significance of the invention, he reported his discovery to the Maritime Museum in Gothenburg.

Archaeologists concluded that it was a ship’s cannon, quite than one which had been transported as cargo, as a result of it nonetheless had components of the cost remaining in its powder chamber when it was discovered.

Which means the cannon was loaded and prepared to be used in fight by the point it ended up on the backside of the ocean.

Because of the preserved stays of the cargo, it was attainable to make use of radiocarbon relationship to find out the age of the discover.

“The shortage of dependable classifications usually makes it troublesome so far remoted finds of early artillery items,” mentioned College of Gothenburg marine archaeologist Staffan von Arpen and colleagues.

“Nonetheless, due to the fabric, Marstrand’s discovery supplies a uncommon relationship alternative, as radiocarbon relationship of the material would additionally not directly date the gun.”

“That is why the fiber samples have been extracted for radiocarbon evaluation. The end result got here again 635 years earlier than the current, offering a attainable date of 1285-1399 AD.”

“The gun most likely dates again to the thirteenth century, though a 14th century relationship is extra sensible in gentle of current written and photographic proof.”

The overall size of the Marstrand gun was 47.5 cm, of which the rear 27 cm shaped the powder chamber and the entrance 20.5 cm the barrel. In its present preserved state, it weighs 18.7 kg.

The barrel is massive caliber and barely funnel-shaped, tapering in direction of a a lot smaller diameter powder chamber.

The researchers documented the invention utilizing 3D scanning and carried out a chemical evaluation of the metallic used to solid the cannon.

Evaluation confirmed that it was a copper alloy containing about 14% (by weight) of lead and solely small quantities of tin.

This alloy isn’t superb for casting cannon, in response to researchers, and the cannon would possible crack and change into unusable if used extensively for longer intervals.

“It’s clear that the one that fired the cannon didn’t have the mandatory data and understanding of the properties of various copper alloys,” von Arben mentioned.

“This reveals that the noble artwork of cannon casting had not been absolutely mastered at the moment, and that manufacturing was largely based mostly on trial and error.”

“The evaluation additionally signifies that the copper ore used within the manufacturing of the cannon was mined in present-day Slovakia, whereas the lead could have come from England or the border area between Poland and the Czech Republic.”

Marstrand-type cannons are normally attributed to the fifteenth and sixteenth centuries, however this discover attests to the truth that this mannequin already existed within the 14th century.

The stays of the cost preserved within the cannon powder chamber additionally present that the usage of cartridges, a sort of textile packaging for the gunpowder cost, got here into use a lot sooner than was beforehand recognized.

“Now, in fact, we additionally wish to attempt to find and doc the situation of the ship to which the cannon belonged,” von Arpen mentioned.

“Though it’s prone to be severely degraded and damaged, it’s attainable to search out scattered stays of the wreckage if we conduct a complete stock of the positioning and its surrounding areas.”

the results Posted in Mariner’s mirror.

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Staffan von Arben et al. 2023. Marstrand Cannon: First Proof of Shipboard Artillery in Europe? Mariner’s mirror 109(3): 260-282; doi: 10.1080/00253359.2023.2225311

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