Floating missiles: 550 tonne crane, oil tanker adrift in flooded Brisbane River

Large tug boats have been positioned on the Brisbane River, ready to tow a now-stabilised 550-tonne crane on a barge back to its home near the City Botanic Gardens.

Large tug boats have been positioned on the Brisbane River, ready to tow a now-stabilised 550-tonne crane on a barge back to its home near the City Botanic Gardens.

Tug boats had been roped to the runaway barge, with an estimated 300m of towing required after the barge ended up near Eagle Street Pier.

It is understood the pylons used to keep the barge floating will be removed before it can be slowly towed back into place.

A pontoon and crane dislodged and caused mass evacuations from all sides of the river. Picture: Amanda Parkinson

The barge sparked a major evacuation emergency earlier on Monday, with authorities worried it would move downstream and slam into parks or buildings, including Howard Smith Wharves.

With the lower tide on Monday afternoon jack legs of the barge were embedded into the river bed.

Several engineers visited the site and continued to monitor the situation into the night.

Meanwhile, a large oil tanker was adrift in the Brisbane River for hours during Monday’s flood drama in what Port of Brisbane insiders say could have sparked a major catastrophe.

The Australian Maritime Safety Authority has launched an investigation into the incident in which the 185m ship, CSC Friendship, broke away from the wharf at Lytton and drifted dangerously down the river.

The Hong Kong-flagged tanker then became stuck on a sandbank near Luggage Point before being refloated by five tog boats.

Port of Brisbane sources say the incident could easily have ruptured the ship’s fuel tank or caused it to ‘dam’ the channel as floodwaters raged.

One insider questioned why Maritime Safety Queensland had not evacuated ships from the port as it had done ahead of the 2011 floods.

“It left a lot of people shaking their heads–- there was plenty of warning that a major flood was on the cards,” a source said.

A huge crane threatens Howard Smith Wharves after breaking some of its moorings. Picture: Amanda Parkinson

An MSQ spokesman said river conditions ‘deteriorated rapidly on Sunday and water flows into the Brisbane River increased exponentially’.

“The actual water flow conditions considerably exceeded the forecast conditions.

“These high water flows caused product tanker MT CSC Friendship, moored at Ampol Products wharf on the Brisbane River at Lytton, to break away from the wharf early this morning.

“The vessel was refloated successfully in an operation overseen by the MSQ regional harbour master with the assistance of a marine pilot and tugs.

“The vessel was taken to an anchorage in Moreton Bay under its own steam and anchored without incident. There was no pollution and no injuries.

“The matter is under investigation by the Australian Maritime Safety Authority.”