When a boat needs to pass under a low bridge on a river, that bridge needs to move out of the way. A drawbridge lifts up so a boat can pass under. A swing bridge pivots out of the way so a boat can pass by. But these decades-old bridges don’t operate on their own. They rely on a small group of “bridge tenders” who specialize in a peculiar and slow-moving job.

When you drive over the Grand Avenue Swing Bridge in New Haven, look up and you’ll see a house. Inside that house is a bridge tender. Someone like Maurice Little who is waiting patiently.

"Some people don’t want to do it because it’s like a boring job," Little said. "You’re just sitting there all day. Waiting on a radio call."

Boats call when they want to pass. Making sure those bridges open when boats need them to.

It’s a lot of waiting.

"My wife, she knows. She said, 'Oh your job is boring.' No it’s not boring. I’m used to it. I enjoy my job," Little said.

Between radio calls Little says he passes the time with a book or on his computer.

His colleague, Mike Dorsey, said even though the job can be slow sometimes, bridge tenders perform a vital service, especially if there's an emergency on the river.

"Somebody has to be on each bridge at all times," Dorsey said. "Because the Coast Guard might need to come through."

The tenders are a commercial necessity, too. Oyster fishermen who travel the Quinnipiac River need those bridges open to farm in Long Island Sound. And then there are everyday boats, filled with summer hobbyists looking to pass time out on the ocean.

I told Dorsey I wanted to go up into that curious house on the Grand Avenue swing bridge.

Dorsey opened the gate and we climbed a metal staircase buffeted by winds. As we walked, cars and buses breeze by underneath.

The whole bridge shook.

"People don’t usually look up here," Dorsey said. "They just ride right through not even knowing that we’re up here. It’s crazy."

Inside the house is a giant control panel with numbered switches like one that turns traffic lights red. Another button drops a safety gate to block walkers and cars. And there are buttons to actually rotate the bridge.

Grand Avenue became a swing bridge around 1896. So the whole process isn’t automated. Instead, it relies on the eye.

Bridge tender Maurice Little remembers the first time his eyeballs were in charge.

"It was scary! I started over here on Grand Avenue," Little said. "You've got to be able to line the streets and the lines up. After you watch and say, 'Well, okay, I know I need to let the button go once the angle of the bridge hits right here. Then everything kind of lines itself up.' But after that, it’s a piece of cake."

Mike Dorsey asked if I want to see one more bridge. It’s on Ferry Street, a 1940s drawbridge just a few hundred feet south. We made a quick scoot down the Quinnipiac River and minutes later, Dorsey introduced me to another colleague, Mike Johnson.

Johnson said tending to bridges can sometimes be slow, but it also can be peaceful, attuning him to nature.

"In the winter you get to see the sun set over near the cement tanks," he said. "Then in the summer, you get to see it set over New Haven, over the downtown area."

For the several hours I was out on the river, I only saw one call. An oysterman who was headed out to the Sound and needed to pass under the Ferry Street bridge.

But Johnson said the slow days are okay.

"I’m not stressed out every day, going home stressed out," Johnson said. "This definitely takes that edge off. Which is, these days, it’s something to be said about."

As I left, Johnson headed back to his tower, anticipating the next radio call.

Until then, he’ll watch the horizon. And he’ll wait.