The wire lobster trap was introduced as a commercial product in 1980, making it a feature on the docks for 35 years this year. However, like many revolutionary products, its process of evolution took much longer.

James W. Knott, Sr., founder of Riverdale Mills in Northbridge, Massachusetts, began experimenting with the wire trap in the 1950s. Long a summer resident of Cape Ann and a lobster license holder, Knott would bring wire mesh to fishermen there.

“He used to bring the wire to the Rockport docks and guys would put it on the sides of wood traps,” said James W. Knott, Jr., CEO of Riverdale Mills. “Then they went to making all-wire traps. That didn’t work, so they went back to traditional heads.”

The problem for lobstermen was marine worms, which liked to eat the traditional half-round wooden slat traps. Wire, however, was not on the worms’ diet.“Worms don’t eat the mesh. Plus it weighs more in the water and less on deck,” said Knott.

Knott Sr. bought the former textile and paper mill on the Blackstone River in 1979, after spending 20 years as president of Coatings Engineering Corporation, the largest custom coating company in the world. Knott Jr. joined the company in 1979, worked as its chief operating officer from 1988 to 1997, “then went off to do other things, inside the industry and out,” he said. He returned three years ago to run the business.

When Knott Sr. introduced the trademarked Aquamesh vinyl-coated wire in 1980, he had already worked for years to perfect the steel mesh by making it impervious to corrosion. His wire traps initially were constructed first, then dipped in vinyl. Eventually he changed that system. Aquamesh wire is produced using a two-step method of fi rst galvanizing rolls of steel mesh (called “galvanizing after welding,” or GAW), then coating with polyvinyl chloride (PVC) to protect the wire from harsh ocean conditions.

The first load of Aquamesh was delivered in 1980 to the coast of Maine, long known as the center of the New England fishery. Traps made with Aquamesh now comprise 80 percent of all U.S. lobster traps.

“We always used to sell the mesh in rolls. One of the big changes we’ve adopted is that 75 percent is now sold in panels for trap builders or fishermen. We take large orders and cut to size, then they fabricate the traps. We also sell tools for bending wire,” Knott explained.

“It’s low-cost and highly effective,” said Knott Jr. “Each fisherman likes to finish in his own way: one or two heads, different colors, etc.” At first the mesh was only green vinyl-coated, but now comes in seven colors. In Maine, the most popular color is yellow, while Canadians favor blue. Some fishermen like to use a different color on the ends or doors to distinguish theirs from other lobstermen’s traps.

Riverdale has competition, primarily from China, but, as CEO Knott explains, while the mesh from China is less expensive it is also less durable, showing signs of rust in as few as two years. “Lobstermen mostly buy ours, which says they care about quality. We make it all, we don’t buy it, so we control the inputs that go into the vinyl,” said Knott. He noted that the Chinese mesh is “not designed for sub-sea use, not as abrasion-resistant, and the sea water extracts some compounds from the vinyl. They chose the wrong inputs because they are economy-driven, not quality-driven. And ours is better environmentally.”

The company buys all its steel in North America, from either the U.S. or Canada. The steel suppliers are given a recipe for the specific chemicals to go into the steel to ensure it has the right amount of elements to weld and galvanize well. The steel comes to the company by a train that delivers directly to the Riverdale Mills factory. “This helps the industry and helps keep rates down to fishermen,” Knott said.

The process starts with hot rolled steel, drawn into wire in any diameter desired.“We start with 1/3-inch rod and make wire, then we weld the wire into mesh. After the weld, there’s a hot galvanized zinc bath that makes the mesh very corrosion resistant,” he said.

Next an epoxy coat is applied followed by a powder coat with PVC. The exact process is proprietary to Riverdale Mills. After coating, the mesh is finished to be sold in either rolls or sheets. “Our product goes several years before there is any evidence of rust,” Knott noted.

The mill where the wire is made had a long and varied history before Knott Sr. began manufacturing coated mesh. It began in the early 19th century as the first mass manufacturer of scythes. Later the mill expanded to forge bayonets for the Union Army during the Civil War. After that it became a textile mill, then in 1910 was turned into a mill for special coated papers. With changes in manufacturing, the mill fell on hard times until Knott bought it.

Riverdale makes several types of wire—galvanized, stainless steel, and copper alloy wire—in many configurations. Besides Aquamesh, the company’s trademarked products include Geomesh for land uses including erosion control; WireWall, used to define parts of the U.S.-Mexico border and the Kuwait-Iraqborder; and SoftStep for the poultry industry. The latest change in Riverdale’s Aquamesh business is in the aquaculture market. One of the biggest uses of the wire now is for cultivation of shellfish, primarily oysters.

“We work closely with a company in eastern Canada called OysterGro. They use our mesh for their products. Usually those products are rectangular baskets used to raise oysters in bags at the surface of the water because it turns out there are more nutrients in surface-level water. You end up with better-shaped oysters,” said Knott.

Knott believes the lobster market has a bright future. Despite the increasing diversity of Riverdale’s product lines and the industries served, in Knott’s mind the lobster industry comes first. “We are committed to the lobster industry. We love all the fishermen,” said Knott. “If it wasn’t for them, we wouldn’t be here.”