Members of Halifax, Nova Scotia, Local 1133 perform maintenance work on the Royal Canadian Navy's most sophisticated vessels — and some are never quite sure where that responsibility will take them, or when.

Weapons fire control technician Tim Bunker was enjoying lunch one afternoon when he was told to head to the airport, where he would fly to perform repairs on a ship docked in Italy.

Business Manager Freddie Hutchison, who works in radar maintenance, arrived at Halifax Harbor for work one day in September 2017 to find he was being dispatched to France that afternoon because of an oil leak on a ship's radar.

These vessels are vital to national security, so the work can't wait.

"When they are in operations, they're not over there to be tied up portside," Hutchison said.

Last year, they were sent to Naples, Italy, to work on the ship that carries the name of their hometown — the HMCS Halifax. At the time, the Halifax-class frigate was serving six months as the flagship of the Standing NATO Maritime Group 2.

Local 1133 has only about 120 members, but few, if any, are more vital to Canada's national security. They are employed by the Department of National Defence and based at Her Majesty's Canadian Dockyard, commonly called HMC Dockyard Halifax, where they are responsible for all the maintenance work on the RCN's Atlantic fleet.

They can be sent around the world at a moment's notice if any part of the fleet requires immediate maintenance.

"Being able to contribute to the defence of the country and the military without being in the military is pretty neat," said Hutchison, who has received thank-you notes from ship commanders and met with Defense Minister Harjit Sajjan. "You definitely get that feeling from this. When you go overseas and do the repairs we do, you're very thankful."

Applicants immediately become members after being hired and go through a three-year apprenticeship conducted by the defence department. The work they do isn't much different from other Canadian industries in at least one respect. Technological change continues at an increasingly rapid rate.

"One of the new challenges we're facing now is that some of the radar is heavily software based," Bunker said. "A lot of that is learning on the fly. It certainly keeps you on your toes."

Some things haven't changed, however. For those working on submarines, like 17-year Local 1133 member Trevor Thibault, that means crawling through the extremely close quarters of the hull and casing of a sub to work on its sonar system.

"I kind of like doing different kinds of things, and working in a submarine was a little different," said Thibault, a former auto body mechanic. "There's more of a mechanical side to it and the confined spaces, I don't mind. If you don't like the smell, it's a real problem. It's a diesel fuel smell that goes through your clothes and your hair pretty quickly. It's just embedded and gets through everything on the sub."

The travel sounds glamorous. It's not. Often times, it's grueling, especially for families left behind at a moment's notice. But there are some highlights.

Instead of sending all vessels back to Halifax for maintenance between missions, the RCN will sometimes dispatch Local 1133 members around the world to perform routine maintenance because it's more cost effective. Thibault spent nearly a month on the Greek island of Crete on such a job, getting weekends off and being able to explore the area with colleagues.

But when it's an immediate repair, Local 1133 members fly in, fix the problem as quickly as possible — sometimes working 15-18 hour days — and are back on a plane to North America quickly.

"Some travel is nicer than others," Bunker said.

The jobs pay well with good benefits, so most members turn them into careers. Doing it in support of the country's military makes it even better.

"It's a rewarding job, doing what we are able to do and help out," Hutchison said. "These military people, I don't think I could do what they do, going away for six months and being away from their families. We're very appreciative of what they do."

Halifax Local 1131 and Ottawa Local 2228, the national local for federal government workers, also represent workers at CFB Halifax.