ODOT Repairs Historic 83-Year-Old Rock Wall

Restoration work is underway on a historic wall along the designated scenic Highway 101 on the Oregon Coast that was originally constructed in 1932.

📅   Thu December 10, 2015 - West Edition
Lori Tobias - CEG CORRESPONDENT


Restoration work is underway on a historic wall along the designated scenic Highway 101 on the Oregon Coast that was originally constructed in 1932.
Restoration work is underway on a historic wall along the designated scenic Highway 101 on the Oregon Coast that was originally constructed in 1932.
Restoration work is underway on a historic wall along the designated scenic Highway 101 on the Oregon Coast that was originally constructed in 1932. Built some 400 ft. (122 m) above the Pacific Ocean, the basalt rock wall stretches as much as 20 ft. (61 m) deep on the seaward side, but stands only 12 in. to 3 ft. (30 cm to .91 m) in height on the roadway. When constructed more than eight decades ago, the wall was part of a highway project that was the most expensive mile of highway ever built by the Bureau of Public Roads, and dubbed as the “half-million-dollar-mile.” The basalt wall is one of four rockwork walls on the coast, and is the second longest span of the four, stretching four-tenths of a mile from milepost 178.82 to 179.18 on the central coast just north of the city of Florence. The wall features two turnouts and a repeated crenellated parapet design. They are doing much of the work by hand because of the historic nature of the wall, which is eligible for listing on National Record of Historic Places. Sections of the wall have fallen into the ocean. Those are being replaced with new rock. But in other places, the rock is being deconstructed, then put back together with new mortar. The project calls for the replacement of Jersey barrier, installed in recent years, with rail that is more in keeping with the original historic rail.

Restoration work is underway on a historic wall along the designated scenic Highway 101 on the Oregon Coast that was originally constructed in 1932. Built some 400 ft. (122 m) above the Pacific Ocean, the basalt rock wall stretches as much as 20 ft. (61 m) deep on the seaward side, but stands only 12 in. to 3 ft. (30 cm to .91 m) in height on the roadway.

“They wanted to put something up so people wouldn’t just go over the side into the ocean,” said Sarah Jalving, Oregon Department of Transportation architectural historian. “But they also realized there were very beautiful vistas. It was built for tourists so they could pull off the road and enjoy the vistas. Today, if we were to build something it would be much, much higher to meet safety standards today. But because of the historic feature, we are able to get design exception so we can build to its historic profile.”

When constructed more than eight decades ago, the wall was part of a highway project that was the most expensive mile of highway ever built by the Bureau of Public Roads, and dubbed as the “half-million-dollar-mile.” It is one of four rockwork walls on the coast, and is the second longest span of the four, stretching four-tenths of a mile from milepost 178.82 to 179.18 on the central coast just north of the city of Florence. The wall features two turnouts and a repeated crenellated parapet design.

The work is being done by contractor HP Civil Inc. of Stayton, Ore. and Tigard, Ore., subcontractor Pioneer Waterproofing Company, a masonry contractor.

“It’s just a simple basalt wall,” Jalving said. “The basalt was mined right on site. Of course it was much easier to get the rock you needed right on site other than having it shipped. Otherwise, you’d have had to put it on flatbeds and have it hauled by donkeys. It would have been quite the situation to get this up there. But it was mined right there. It’s got different depths as it undulates with the topography.”

Sections of the wall have fallen into the ocean. Those are being replaced with new rock. But in other places, the rock is being deconstructed, then put back together with new mortar. Much of the work will be done by hand, and what equipment there is on the site is generally small, such as an extended-reach forklift, small propane warehouse forklift, large air compressor, two 40-pound jackhammers and scaffolding.

“We’re using equipment,” Jalving said. “But we’re not using big equipment. There is not much land up there, just two lanes and a couple of pullouts. There’s no way we can use super-sized machinery.”

They also are doing much of the work by hand because of the historic nature of the wall, which is eligible for listing on National Record of Historic Places.

“The biggest challenge is the actual physical deconstruction of the wall, having to find the correct size replacement rock, how the wall needs to go back together so we have a nice strong wall and are doing it in a fiscally responsible manner,” Jalving said. “Also, the challenge of the deconstruction of a historic resource. We have to find the right quarry to get the right stone. We need to think about the mortar mix we are going to use so it’s not going to harm the historic wall.”

The project also calls for the replacement of Jersey barrier, installed in recent years, with rail that is more in keeping with the original historic rail.

When the project is finished, contractors will apply a special coating to the rock to give it an older look.

“It’s pretty exciting,” said Jalving. “We are going to do milk and lichen mix and spray it on the rock wall. It supposedly will give the whole wall a lichen-y sheen to it and will help it grow some of the mosses it has on it now. It won’t look like it’s brand spanking new, but will give it a little covering so it blends in nicely, so it looks like it did before we started the reconstruction.”

Completion is scheduled for April 2016.