“That’s good. Keep going. You can do it.”

That’s my 3-year-old grandson, Coach Emerson, who turns 4 in April. He’s talking me across a rope bridge strung between towers at a neighborhood park.

Emerson considers us equals though I drive us to the park and have money for treats. He keeps his money in a bank at his house.

The rope bridge is a stout hawser with thin, waist-high guide ropes on either side.

When Emerson walks the rope bridge, the guides are over his head just within his grasp.

When you are 3 years old, soon to be 4, parks are a proving ground. Emerson has mastered the towers, slides, ladders, climbing walls and, now, the rope bridge.

He is passing on to his grandfather the expertise required to cross this U.S. Army-style obstacle course rope bridge.

A year ago, I stood anxiously beside the ladder to the slide as Emerson climbed before zooming back to earth. It was hard not to dive at the last second to catch him.

He was so little, so precious and so eager to please himself and me.

The rope bridge concerned me until I’d given it a try. A wonderful piece of design, the foot rope is thick enough to accommodate even large feet and heavy enough that it doesn’t sway.

I was tempted to try it without the guide ropes but didn’t want to give my charge for the morning any ideas.

Isn’t it funny? We guard our children’s safety with our lives, then turn them lose at a park where rope bridges, slides and tall towers beckon.

True, what grandsons and grandfathers fall on at parks is the softest bed of mulch but it’s the falling that bothers me.

Emerson thinks me old, but he expects me to keep up. He’s just out of babyhood. I’m four years shy of 70. He thinks that’s about the right separation in age for a grandson and a grandfather.

When Emerson runs, I can still catch him. The trick is to overtake him in the first few yards of pursuit.

I’ve tried to stay in shape because it makes me feel good. Having grandsons ranging in age from 18 years to 18 months, Emerson’s little brother, has given me reason to ride a bicycle, watch my weight and try new things at the park.

I feel close to my son when I call him up from the park. He’s at his desk in Lafayette working. Emerson and I are under a glorious, warm sun with just enough chill in the air to make jackets feel good.

We’ve been to breakfast at Zeeland Street Market. We’ve bought batteries and candy from a counter clerk named Jane at Bolton’s drug store.

We’ve filled my wife’s car with gasoline so she can return Emerson to his parents and little brother John Hudson.

We’ve topped off our morning together by each mastering a rope strung between towers. We are pleased with ourselves and ready for lunch.