The added volume of corn harvested per pass presents several engineering challenges. Marion Calmer believes they have dealt with those issues on the 40-foot head.

“Anybody can build a frame and row units and put the units on the frame,” Calmer says. “But there are three big obstacles to making it work: the weight of the unit, the additional horsepower needed and the ability to deal with more trash intake.”

Calmer heads use a single chain, rather than a double, as the main mechanism. “I would say our unit is 100 pounds lighter, per row, than most other conventional units,” he says.

It takes less horsepower to run one gathering chain, according to Calmer. The Calmer unit also uses one big paddle per row, rather than two, to act as a kind of “retaining wall” to keep the ears engaged in the single chain, he says.

The head uses patented combo stripper plates that are longer and can better harvest low-hanging ears on downed corn. A bevel on the second stripper plate allows the stalk rolls to make contact with more corn leaves, shanks and husks, which reduces trash intake into the machine. Less trash in the combine lowers horsepower requirements.

Even though Calmer has introduced a head for harvesting 12-inch-corn rows, Howey predicts he’ll stay with 15-inch rows. “I’ve got a 15-inch row planter that I use for soybeans, so I’m happy to be able to get double duty out of it,” he says. “I don’t have to get a special planter for 12-inch-corn.”

As the total acreage for narrow-row corn in the U.S. increases, Howey predicts more manufacturers will introduce their own narrower-row products. John Deere introduced a corn head for 20-inch rows in 2012.