According to the U.S. Coast Guard, ships anchored in the Detroit River near downtown Windsor will get moving early on Tuesday morning with the help of a Canadian Coast Guard icebreaker.

However, another freighter anchored near the Ambassador Bridge might not.

The icebreaker Samuel Risley will be leading two ships to the St. Clair River. That's where a United States Coast Guard icebreaker will take over.

"In the last ... four days, that's where we've been having most of the problems," said petty officer Ross Flowers with the U.S. Coast Guard Detroit.

The U.S. Coast Guard co-ordinates winter icebreaking on the Great Lakes. It's called operation Coal Shovel, a throwback term for when there were more frequent shipments of coal during the winter months.

Flowers said it's been two years since icebreakers were needed.

"The last two winters have been pretty mild," said Flowers. "I can't remember a single freighter being beset by ice at all."

Meanwhile, Gary Jay Scott, a wheelsman on the CSL Tadoussac, said he can't remember a time when ice had caused so many shipping delays. Scott said he's been working on ships in the Great Lakes since 1975.

Scott said the Tadoussac is anchored near Sterling Fuels, close by the Ambassador Bridge, along with another ship. He said there's no word on when the ship will get moving. 

"The shipping season actually never ends on the Great Lakes," Flowers said. "Great Lake freighters run year round."

The cold snap - with near record lows recorded in Windsor - is causing the ice to form on the Detroit River and the St. Clair River.

"It's potentially something that's only going to get worse in the next couple of days," said Flowers, who added that the ice forming on the St. Clair River is like a giant frozen snowbank, one that's harder to break up than simple "plate" ice.

Flowers said the ice poses no danger to the ships, but added that in open water, like out in Lake Erie, an ice pack can shove a ship towards shallow water.