AIC's 52nd Annual Meeting

Lighthouses are a readily recognizable and dependable landmark for marine navigation but have undergone many changes over the last 150 years and continue to face new challenges from a changing climate and from economic constraints. A comparison of four lighthouses on the Pacific coast of Oregon and Washington: Cape Blanco, Heceta Head, Yaquina Head, and North Head, show the impact that changing materials, operations and maintenance procedures, and weather conditions have had on the condition of these iconic structures. Almost 90 lighthouses were built along the west coast of the United States to aid marine commerce, most during the second half of the 19th century. Their initial construction and operation by the United States Lighthouse Service was highly standardized but adapted to local conditions and available materials. The operation of oil or kerosene lamps required constant supervision by a team of residential lightkeepers who also regulated ventilation and provided regular maintenance of the painted cast iron and lime washed stucco and brick towers. After the US Coast Guard assumed ownership and operation of most lighthouses in the 1930s, residential keepers were gradually eliminated as the lighthouses were converted to electric lights and were fully automated by the 1960s. During this same period, in an effort to exclude the harsh marine weather while reducing maintenance, the USCG infilled windows, closed vents, and replaced lime stucco and whitewash with modern cement stucco and elastomeric coatings. However, wind driven rain penetrated the tiniest crevasses, and eventually saturated both cast iron and masonry, where the moisture was trapped by impervious coatings and lack of ventilation. The preservation movement of the late 20th century focused attention on the deteriorated condition of the lighthouses, and led to increased advocacy, and transfer of most lighthouses to federal or state agencies, although the Coast Guard retained ownership or responsibility for maintaining most of the navigation lights. Cape Blanco was partially renovated in the 1990s but today has multiple layers of impermeable paint and is suffering from internal moisture damage. Yaquina, Haceta Head and North Head were extensively restored in the early 21st century with traditional materials that are more sympathetic to the original construction, but continue to fight internal humidity, metal corrosion and algae, lichen and abrasion of the exterior finishes. Partnerships between state and federal agencies and other advocacy groups have increased advocacy and stewardship of the lighthouses but the harsh weather has proven to be a formidable foe.