The 550-foot long, 125-foot wide vessel was nursed through the South Channel by four tugs -- Bermuda's Faithful and Powerful and the Crowley company's ocean-going tugs the Crusader and Ensign .

The Second World War era Sustain -- which is not self-propelled -- draws about 2.3 metres and is used to supplement the US Navy's shore-based repair facilities by providing repairs on the open ocean and in forward combat zones.

She experienced tow line problems earlier this week and has put into Bermuda for repairs. Two US Navy supply ships escorting Sustain are now on their way back to an American port.

Once a secure tow line can be reattached, Sustain will continue on its trip to Jacksonville.

Photos by David Skinner On course: The US Navy's Sustain and a Government tug make their way through the South Channel yesterday, en route to Dockyard.

Steady on stern: The Crowley tug Crusader pushed from behind.

Window of opportunity: A break in the weather allowed four tugs to nurse Sustain through the South Channel.

Pulling power: The ocean-going tub Ensign plows through the South Channel with her 8,000-plus tonne load, Sustain. The huge floating day-dock is not self propelled and must be manoeuvred by support ships. Sustain was built in 1945 to provide repair service at seas or in forward combat zones.