Logging

There is a timber company logging on our road, about 1 mile away.  We can't hear the saws or see the trees, unless we drive by.  However, I can hear the trucks driving by.

The trucks full of logs that are using the road.  The trucks full of logs downshifting gears and using their Jake brakes on the hill and curve before they gun their engines to get up the next hill.  Then they are turning around and coming back the same route. Using their brakes again, in the opposite direction. 

It's noisy and startles all of the cats.  And me. 

Commonly called Jake brakes, they are actually engine brakes.  Engine brakes are the ones that make that distinctive staccato sound. 

Brrrraaaaaaaaaapppppppp

The brakes are made by the Jacob Company.  The Jacob Company produces several different types of brakes.  Some are quiet. 

Unlike the wheel disc brakes on your car, large diesel trucks have a compression release engine brake.  The jake brake opens the exhaust valves to create drag on the engine by releasing the compressed air so the fuel won't ignite.  Diesel engines don't have spark plugs like gasoline engines.  They rely on compressed air to ignite the fuel.

The driver can adjust how many cylinders to open to slow the engine. 

The noise comes from poorly muffled or unmuffled exhaust systems, or exhaust systems that have been illegally modified or are poorly maintained. Not the engine brake. 

Let's hope they finish logging soon and they don't put a new housing development where they logged.