Some very tense moments on the Detroit River when a huge bulk carrier ship came adrift.

The 730-foot long Algoma Niagara broke free at its bow mooring around 4:30 a.m. Monday.

Windsor Port Authority CEO Steve Salmons says they were notified immediately by the Transport Canada shipping control centre in Sarnia.

It was a near miss for an environmental disaster as the anchor was dropped where the Kinder Morgan pipeline crosses.

The Canadian side of the river was closed to shipping to prevent any possible collision.

He says the river moves at about 7-miles-an-hour at that location.

"The river's current just naturally started pulling the ship, rotating it 90-degrees out into the river channel. The captain did what was appropriate and dropped anchor and the anchor stopped it . From our point of view as port authority, there was now an interference in the shipping lanes."

Salmons says where the ship came to a halt raised a concern for underwater damage.

"There is a pipeline that runs through there and so of course there was immediate concern. We contacted the pipeline company who indicated to us that through their guages and monitoring equipment that there was no loss of pressure so there was no strike to the pipeline."

He says the Algoma Niagara had to detach its anchor, which will be recovered later.

Salmons says a dive team was dispatched to take a look underwater, but they weren't trained to work in a current that fast.

Kinder Morgan did de-pressurize the line for a time as a precaution, but it has since returned to service.

Around 1 pm, the all-clear was given and tug boats have manoeuvered the ship back to the shore where it will continue unloading it's cargo of aggregates.