Field Guide to Math in Humboldt
No. 20 Dolos (plural Dolosse)
These massive 42 ton steel reinforced concrete bodies that have the appearance of a capital H with tapering arms and one of the uprights turned 90 degrees. They were invented in South Africa, modeled after dubbeltjie thorn and named after knuckle bones used by South African healers and as toys
Their installation in Cresent City harbor and Humboldt Bay was the first use of the design in the United States. 4,785 of the interlocking dolosse were carefully positioned on the ends of the north and south jetty in early 1970's. In 1985, 1000 more were added to the jetties.
The dolosse work by absorbing and disbursing the force of waves. Prior to the installation of the dolosse, 100 ton blocks were washed off the jetties by winter storm waves
In 1977 the jetties were dubbed a Historical Civil Engineering landmark. South Africa has even honored the design with a 2 Rand coin.
Dolosse number 1,972 sits at 2112 Broadway, in front of Harbor Lanes and the old Eureka Chamber of Commerce building. You can also visit the jetties and see the dolosses in place, but avoid the area during stormy weather and always be on the lookout for sneaker waves that can completely cover the jetty.
Their installation in Cresent City harbor and Humboldt Bay was the first use of the design in the United States. 4,785 of the interlocking dolosse were carefully positioned on the ends of the north and south jetty in early 1970's. In 1985, 1000 more were added to the jetties.
The dolosse work by absorbing and disbursing the force of waves. Prior to the installation of the dolosse, 100 ton blocks were washed off the jetties by winter storm waves
In 1977 the jetties were dubbed a Historical Civil Engineering landmark. South Africa has even honored the design with a 2 Rand coin.
Dolosse number 1,972 sits at 2112 Broadway, in front of Harbor Lanes and the old Eureka Chamber of Commerce building. You can also visit the jetties and see the dolosses in place, but avoid the area during stormy weather and always be on the lookout for sneaker waves that can completely cover the jetty.