The union that represents Fredericton's outside workers formed a picket line Saturday afternoon at the entrance to the city's depot on the north side of the city.

About 50 people from CUPE Local 508 blocked the entrance while replacement workers were inside training to step into the jobs of the locked-out workers. The union allowed vehicles through that weren't affected by the lockout.

Outside workers include snowplow operators, mechanics and staff who maintain the city's drinking water.

The city locked out its workers Friday afternoon following failed talks and mediation between city administrators and the union.

The workers served the city with a 24-hour strike notice at 4 p.m. Thursday, but a council vote Monday directed the city to lock out the workers in the event of a strike.

Union members stopped this van from entering the depot Saturday afternoon. They eventually let it through. (Gary Moore/CBC)

Fredericton council held a special meeting Friday evening and voted to hire replacement workers to fill the roles during the lockout.

"We're all upset," Kevin Smallwood, president of the union local, said at the picket line Saturday afternoon.

"Why would the city bring people from out of province to work in a place where we live and work?"

The city hired AFIMAC Canada to fill the jobs. The employees are not from Fredericton.

Jeff Trail, Fredericton's deputy CAO, said the workers were hired to make sure the city could handle severe weather.

"Our primary concern right now is public safety, ensuring the safe passage through the streets and roads within the city," Trail said Saturday afternoon.

Picketers in front of the city's north side depot blocked a white van carrying some replacement workers Saturday afternoon.

Kevin Smallwood is the president of CUPE Local 508. (Gary Moore/CBC)

Picketers shouted at the van and stopped it from entering the parking lot at first. They eventually allowed the vehicle to inch toward the depot every few minutes.

Police were on the scene and helped guide the vehicle through the crowd over an hour.

Trail said some of the replacement workers were receiving training Saturday at the depot.

"We want to get them familiar with our pieces of equipment, and familiar with the routes that would need to be run in the event that we have a winter storm."

Smallwood believes the fact that the city hired replacement workers is a sign that they could be locked out for a while.

"This is sending a message that we're not ready to negotiate with you — we're going to have you guys out and make you feel the burn instead of getting you back to the table," Smallwood said.

As of Saturday afternoon there were no talks scheduled.