Mukilteo light shines brighter

By Mukilteo Historical Society | Feb 13, 2019
Courtesy of: Mukilteo Historical Society Chad Kaiser cleaning the fourth order Fresnel lens on display in lighthouse lobby.

Mariners may notice the Mukilteo Lighthouse beacon shining brighter as a result of cleaning its historic Fresnel lens two weeks ago. Mukilteo has the only active, Fresnel-lens-equipped lighthouse in Washington state.

The Mukilteo Historical Society engaged the services of Chad Kaiser, general manager of the New Dungeness Light Station Association, to clean both the active lens in the tower and a display lens in the Mukilteo Lighthouse lobby.

These historic lenses are quite fragile and require special care when cleaning. Only a Coast Guard-approved technician is allowed to work on the active lens, and such approval requires significant training and many years of experience before being granted. Kaiser used special liquids and cloths to clean the glass and brass supporting fixtures. The items had not been cleaned in several years.

Mukilteo’s active Fresnel lens was manufactured in Paris, France, in the 1850s. This type of lens was invented by the French physicist, Augustin Fresnel.

The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. Its combination of glass lenses and prisms can capture more oblique light from a light source, thus allowing the light from a lighthouse equipped with one to be visible over greater distances.

There are various sizes of Fresnel lenses (described by orders) used in lighthouses. Mukilteo has a fourth-order lens, which is about 28 inches tall. It uses a 150-watt halogen bulb, which flashes on for two seconds and off for three seconds.

Due to the focusing power of the Fresnel lens, the light can be seen for about 12 nautical miles on a clear night. The apparatus, which was electrified in 1927, and completely automated in 1979, operates continuously, day and night.

The original apparatus was a small kerosene lantern set within a different fourth order Fresnel lens that rotated on ball bearings. Keeping the light shining meant carrying kerosene up to the lamp every three hours, winding the clockwork weight system to maintain the rotation, trimming the lantern wick and adjusting the air intake in the tower, as well as the nearly constant cleaning of the tower glass and the lens itself.  These were the jobs of the lighthouse keepers who lived at the light station.

In 1939, the United States Coast Guard replaced the Lighthouse Service as keepers of lighthouses throughout the United States. Until 1996, two Coast Guard families lived in the houses on either side of the Mukilteo Lighthouse tower. These houses are now used for historical exhibits, archival storage and a gift shop operated by the Mukilteo Historical Society.

The city of Mukilteo now owns the light station buildings and grounds, while the Coast Guard owns the Fresnel lens, associated light apparatus and foghorn. The Mukilteo Historical Society provides volunteer docents for the public to tour the lighthouse and learn about its history. The Mukilteo Historical Society also works in collaboration with the city to maintain the buildings and grounds. The grounds and surrounding park are open to the public all year. The lighthouse is open to the public on weekends April through September.

The Historical Society recently contracted with an historical building inspector who provided recommendations on how to preserve and protect Mukilteo’s lighthouse structure. Supported in part by a grant from the Lighthouse Environmental Program (LEP), the Historical Society expects to collaborate with the city to implement high priority recommendations to ensure our iconic gem continues to shine brightly for many years to come.








Chad Kaiser cleaning the active fourth order Fresnel lens in lighthouse tower. (Courtesy of: Mukilteo Historical Society)
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