A PORT operator has been hit with a £650,000 fine over failings seven years after the deaths of three men on board a tug that capsized on the River Clyde in thick fog.

The Flying Phantom rolled over as it towed a bulk carrier on the river near Clydebank. The tragedy, which happened less than a week before Christmas 2007, deprived three sets of children of their fathers.

Clydeport received the fine yesterday after it admitted breaching the Health And Safety At Work Act by failing to have prepared an adequate contingency plan in the event of fog while a large vessel was being towed.

It also admitted failing to provide a safety management system and to appoint a suitable individual or individuals as the designated person.

Lawyers for the victims' families' said the penalty sent a clear message to operators that safety must come first.

Andrew Henderson, a partner with Thompsons Solicitors, said: "This fine imposed on ­Clydeport shows how serious the breaches of health and safety regulations were.

"The sentence sends out a clear message to all companies who operate on the River Clyde that safety must come first."

Mr Henderson also called for a Fatal Accident Inquiry (FAI) to commence immediately into the deaths so lessons can be learned.

He added: "Now this ­prosecution is at an end the Crown Office must, without delay, begin an FAI into the Flying Phantom's sinking. This is the only way we can learn lessons from this awful accident to make sure something like this never happens again"

Clydeport's guilty pleas came before it faced a trial at the High Court in Edinburgh, a case that could have lasted up for 12 weeks.

The Phantom's master, Stephen Humphreys, 33, from Greenock, Inverclyde; engineer Robert Cameron, 65, from Houston, Renfrewshire; and rating Eric Blackley, 57, from Gourock, all lost their lives in the tragedy on December 19, 2007.

Fellow crewmate Brian Aitchison, then 37, survived.

Lord Kinclaven told the court he was required to mark the seriousness of the offence by imposing a substantial fine.

But he added during yesterday's hearing: "There is nothing I can do or say in this court that can compensate for the tragic deaths of the late Stephen Humphreys, Robert Cameron and Eric Blackley, or for the ordeal suffered by Brian Aitchison."

The penalty adds to a £1.7million fine imposed on the tug's owners Svitzer Marine for health and safety breaches.

Advocate depute Gillian Wade, QC, told the court in the Clydeport case: "The charge before the court relates to failures on the part of Clydeport to adequately assess risks and provide a safe system of work.

"The present charge is not that Clydeport was the proximate cause of the December 2007 incident by their failures."

The prosecutor said the introduction of new work instructions had ensured "a more robust safety regime for those engaged in towage on the Clyde".

She told the court a suitable and sufficient risk assessment should have addressed the issue of large vessels encountering thick fog during transit.

Richard Keen, QC, counsel for Clydeport, told Lord Kinclaven that when Svitzer pled guilty it was on the express basis their breaches of duty that had caused the "girting" - the sinking of the tug.

The court heard the Flying Phantom was involved in a previous incident in 2000 when it was holed after an Egyptian cargo ship collided with it while it was towing in thick fog.

A Clydeport spokesman said: "Whilst we have enormous sympathy for the families and workmates involved, the Crown has clearly stated our work systems did not cause the Flying Phantom tragedy."

It pointed out the court had accepted there had since been significant improvements in safety on the river.