DETROIT (Reuters) - Detroit police postponed plans to raise what is believed to be an 18th century cannon from the Detroit River on Wednesday after treacherous currents and poor visibility made the mission impossible.
A Detroit police diver found the cannon in about 30 feet of water off a downtown convention center during a training session in July, said Joel Stone, curator for the Detroit Historical Society. It had been due to be raised on Wednesday.
"The current is running about twice as fast as normal," Stone said. "The police divers were not able to get the straps on it to get it up."
Visibility was especially poor in the area where they were diving, using a Coast Guard cutter as a platform for the operation, Detroit police Sergeant Eren Stephens said.
No new date was announced to recover the cannon, which is about five or six feet long and weighs about 1,200 pounds.
Four other similar cannons have been recovered from the same general area of the Detroit River in recent decades: one in 1984, two in 1987 and a fourth in 1994, Stone said.
The cannon found in 1984 predated 1760, Stone said. One brought up in 1987 was made in England and the other had a fleur-de-lis, suggesting it was French, he said. Most cannons of that era were made in England, France or Germany.
The cannons would have been old by the time they reached the frontier and recovering a fifth might help answer the question as to how they ended up in the river, Stone said.
"I'm guessing they probably found their way to the bottom of the river sometime in the 1790s, but that is all speculation," Stone said. "I've heard all kinds of different stories about how they might have gotten there, but none of them have been documented."
Cannons of that type and weight were rare and the French, British and Americans were protective of them, Stone said. Once in the river, recovery was impossible, he said.
"These were powerful guns," he said. "To lose five of them would have done somebody badly."
Stone said the fact that no notes have been found from one commander to another disclosing such a loss has fueled speculation they may not have been lost at the same time.
The cannons were found in an area of the river near Cobo Arena, which was offshore from a wharf in the 18th century.
Once pulled from the river, historians will assess the cannon's condition, measure it, note markings to determine where it was made and then return it to a safe location in the river until a plan can be prepared, he said.
The historical society needs to find funding to preserve the cannon and prepare it for display, likely several years from now, Stone said. The river is the best spot to prevent further deterioration until the cannon can be preserved.
"The cold fresh waters of the Great Lakes are the finest preservatives for shipwrecks and all the stuff on them," he said. "Put it back where it has been and it will be happy."
(Writing by David Bailey, Editing by Cynthia Johnston)