Sound Transit is addressing train noise with everything from track-lubricating devices to switches that don't go "ka-thunk" when trains roll over them to turning down the volume on speakers that warn of approaching trains.

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After a year of putting up with the sound of screeching light-rail trains, people who live around the Mount Baker Station ought to be enjoying some peace and quiet.

In the wee hours of Saturday, Sound Transit installed a pair of solar-powered lubricating machines in the southbound trackway to squirt a biodegradable gel onto the tracks every time a train goes by.

One machine sits in the curve from the Beacon Hill Tunnel to the elevated train stop, the other between the train platform and the downward ramp to Martin Luther King Jr. Way South.

The devices are among a number of ways Sound Transit is responding to various noise complaints along the South Seattle route, which opened for passengers last July.

Two similar lubricating machines were installed two weeks ago for northbound trains at Mount Baker Station, said project director Johnathan Jackson, and others were placed in Tukwila.

“We are going all-out to get rid of this noise,” Jackson said, before sending a small crew out in a downpour to fasten the new equipment.

Link passengers can spot the lube sites by looking for rectangular solar panels mounted on yellow posts. Next to them are blue cabinets housing 2-gallon lube containers.

When a train approaches, its vibrations set off a sensor in the railbed. A coaxial cable transmits a signal into the cabinet, and for each train, the device pumps a cubic centimeter of gel through a tube and onto each track.

The biodegradable gel sticks to the train wheels for about the next 1,000 feet, Jackson said, until the train leaves the curved area that is prone to loud noise.

Indeed, before the job late Friday night, the not-yet-lubricated southbound train wheels squealed around the curve as they’ve done for months while the lubricated northbound train was scarcely audible.

The work is part of a broader effort to reduce noise, at a cost expected to be more than $1 million.

In one spot farther south, at the rail line’s new Duwamish River Bridge in Tukwila, noise has been as loud as 83 decibels — exceeding federal standards and prompting Sound Transit to declare the noise a health hazard last September.

In December, rails were ground down in places to reduce friction. But noise actually increased in north Tukwila. The next step is to install rubber mats to absorb or deflect sound near the rail bridge.

In Rainier Valley, the volume has been turned down on several automated speakers at intersections along MLK Way, meant to warn pedestrians and motorists about approaching trains. People had complained the warnings could be heard a quarter-mile away.

And track switches are being replaced with different-shaped switches that don’t go “ka-thunk” when trains roll over them.

Mike Lindblom: 206-515-5631 or