THOMASTON – Selectmen are investigating options for enacting a “quiet zone” ordinance that would control use of so-called Jake Brakes on trucks around town.

Town Manager Valmore Blastow Jr. said selectmen are trying to find model ordinances to assist the town in drafting an ordinance that would be aimed at stopping commercial truckers from using engine brakes unnecessarily.

Jake Brakes – as they are commonly called – are often found on large trucks that carry heavy loads. They are also known as engine brakes and are made by various companies.

The braking system allows a driver to remove from service some of a truck’s engine cylinders by exhausting compressed engine gases from the cylinders before they have a chance to force the cylinder back down.

The braking system can be activated or deactivated by a switch or brake in the truck. The system slows the vehicle dramatically, requiring less effort than traditional braking.

On Thursday, Blastow said the sound from the braking system is worsened when a vehicle has a defective or modified exhaust system.

Some towns have erected “No Jake Brake” signs without tying the demand to an ordinance, Blastow said. In those cases, the town can’t take enforcement action.

The town could simply put signs up in hopes that truckers would respect the wishes of residents, he said. On the other hand, the town needs to research how such an ordinance would be enforced.

Camden Town Manager Roger Moody said that Camden does not have an ordinance, “just advisory signs.”

Initially, the signs read: “Please No Jake Brakes” and included a measurement such as “for the next mile.” The town changed the signs to read: “Please No Engine Brakes,” after receiving a letter in August from the manufacturer of the braking system, which advised the town that Jake Brake is a trademark name.

Jacobs Vehicle Systems manufactures the Jacobs engine brake.

“The use of this name is an unfair use of the Jacobs trademark,” the letter read. “Rather, we would like to work with you to encourage the enforcement of existing noise laws that apply to heavy trucks.”

The letter noted that Portland, Ore., has a state vehicle code regulating the operation of unmuffled engine brakes. In the Portland area, signs read: “Use of unmuffled engine brakes prohibited except in an emergency.”

According to the letter from Jacobs Vehicle Systems in Bloomfield, Conn., “the primary source of excessive noise produced by engine retarders is due to trucks operating with improperly maintained, defective or modified muffler systems; or, in the most offensive instances, the use of straight exhaust pipes with no mufflers.”

When asked whether the signs have been effective, Moody said, “Yes. I think the bed-and-breakfast owners would say it has helped.”

Similar signs are used in Searsport and Gardiner, Moody said.

In September, Houlton passed an ordinance banning the use of engine brakes in most sections of town between 10 p.m. and 6 a.m.

Last month, Dover-Foxcroft selectmen voted to post advisory signs, asking truckers not to use the braking system within town limits.

If an ordinance were developed in Thomaston, the “quiet zone” could be townwide or targeted to areas, such as Beechwood Street, where the commercial truck traffic is more prevalent, Blastow said.

Selectmen may hold a public hearing to obtain comments from residents and truckers. No date had been set.