HALIFAX -- It has a wide girth and, at 46 years old, is a bit rough around the edges.

But the last of Canada's steam-powered warships -- HMCS Preserver -- has a well-earned reputation for staying the course and getting the job done.

The Royal Canadian Navy's last operational support ship -- known officially as an auxiliary oiler replenisher -- was scheduled to be officially retired from service today after a storied career at the frontlines of history.

"It's the last of the steamships," says retired commander Colin Darlington, who served as the ship's second-in-command between 2001 and 2003.

"The operational support ships allow Canada to keep ships out at sea -- regionally or globally -- for extended periods of time ... They keep the fuel and the parts coming."

The big ship's motto is, "Heart of the Fleet."

Built in New Brunswick by the Saint John Shipbuilding and Dry Dock Co. and commissioned in July 1970, the venerable tanker is a floating grocery store, gas station, repair shop and helicopter hangar.

"It provides one-stop shopping," says Darlington, who served in the navy for 42 years.

Aside from food, fuels and other basic supplies, Preserver also carried ammunition, two landing craft, a dentist, doctor, specialized repair teams and a small hospital with four beds and two operating rooms. It was even equipped to process garbage from other ships.

Some sailors had a nickname for the 21,000-tonne ship: Atlantic Superstore, after a regional grocery chain.

And even though the ship usually played a supporting role, it often near the front lines of key global events.

The 9/11 terrorist attacks in the United States came a month after Darlington joined the ships' company. A month after that, in October 2001, Preserver was dispatched to the Arabian sea for six months as part of the U.S.-led war on terror.

On Dec. 17, 2001, the ship replenished fuel for seven ships from five countries. Working non-stop from sunrise to sundown, the crew also slung 134 pallets loaded with supplies to ships cruising alongside at 12 knots, usually accomplishing the task in less than two minutes.

"I called it the dance on the deck," the former executive officer says, referring to the precise co-ordination of sailors and heavy machinery on a rolling deck.

And there were times the ship conducted its own patrols, hailing more than 1,100 vessels and sending boarding teams to 12 of them, including two Iraqi tankers.

"We called ourselves a big, fat, slow frigate," Darlington says with a chuckle.

Earlier in its career, Preserver acted as a supply ship for Canadian peacekeepers in Cyprus in 1974, and took part in several UN missions, including the enforcement of sanctions against Haiti in 1993 and the former Yugoslavia in 1994. The ship also helped with recovery efforts after the Swissair crash off Nova Scotia in 1998, a gruesome task that saw the vessel used as a floating morgue.

Preserver is the last of the navy's three oilers that were built in the late 1960s as the Cold War prompted the Canadian navy to hone anti-submarine skills acquired during the Second World War.

"There is still among the western powers a need for a strong anti-submarine capability," Darlington says. "Canada is still one of the best."

But that world-class status has been eroded by the fact that the Royal Canadian Navy no longer has its own support ships, Darlington says. HMCS Provider was retired in 1998, and Preserver's sister ship, HMCS Protecteur, was retired in May of 2015.

"Having an oiler is one of the significant indications of whether Canada is just a local navy or a global navy," he says. "If we want to be engaged off Haiti, or if a hurricane has hit a South Pacific island, or there is trouble off the shores of Libya or Somalia ... you need to have that support capability."

The federal government's joint support ship replacement program with Vancouver's Seaspan shipyard isn't expected to deliver the first of two ships until 2020 at the earliest. Meanwhile, Canada is leasing oilers from Spain and Chile, while a German container ship is being converted into a modern oiler at the Davie shipyard in Levis, Que.

As for Preserver, Darlington says he expects the ship to be broken up after it is "paid off," a term that dates from the day when sailors were paid wages owing as they went ashore, during a special ceremony at its home port, HMC Dockyard in Halifax.

A quick look at HMCS Preserver, the Royal Canadian Navy's last operational support ship, scheduled to be officially retired from service Friday after a storied career at the frontlines of history.

  • Ship's company: about 270.
  • Displacement: 21,000 tonnes.
  • Maximum speed: 20 knots.
  • Built by: Saint John Shipbuilding and Dry Dock Co. Ltd.
  • Commissioned: July 30, 1970.
  • Hangar: room for three helicopters. .
  • Fuel: can transfer 1,300 tonnes of fuel an hour while travelling at 12 knots.
  • Role: auxiliary oiler replenishment ship.
  • Length: 171.9 metres
  • Width 23.2 metres
  • Propulsion: steam turbines.
  • Range: 6,600 kilometres.
  • Initial cost: $30 million.