Monday, April 15, 2013
New Rails at McCullough's Cape Creek Bridge
Conde McCullough, Oregon’s prolific State Bridge Engineer, was responsible for something on the order of 900 bridges constructed over the first decades of the Oregon State Highway Department’s effort to “Get Oregon out of the Mud!” that began in 1913. McCullough has achieved near iconic status in Oregon, and in fact nationwide, for the combination of beauty and function that he brought to the task. Many of Oregon’s most scenic places, at river crossings and canyons, benefit from his skill. Nowhere is McCullough’s impact more noticeable than on the Oregon Coast, where what is now US 101 wouldn’t exist without the many McCullough-designed spans that cross the rivers and creeks draining into the Ocean.
Last week I was at the Cape Creek Bridge, at Heceta Head, just north of Florence. While not as dazzling or well-known as the famed “Coastal Bridges” that span major rivers, Cape Creek is still a pretty spectacular design. It’s probably fair to assume that some of the lessons learned here in 1931-32 helped guide the design of the landmark bridges that were to follow. Cape Creek is also important for its recent history, being the first bridge in Oregon to benefit from “cathodic protection,” a nifty system where a low-wattage (900w) electrical charge is run through the all the reinforcing steel inside the concrete, providing protection against the salt-spray intrusion that doomed the Alsea Bay Bridge.
Unfortunately when that system was installed at Cape Creek in 1991, the bridge rail wasn’t included (it was likely already damaged). Years earlier, in 1978, a standard “flex-beam” or w-rail had been installed to keep an errant vehicle from crashing through (lovely, isn’t it?). Last week it was obvious that major elements of the starburst pattern railing (it looks really cool when the light comes through…sort of a shadow-picture) are literally crumbling away.
This week, through HERITAGE, I am working on findings for OBEC Consulting Engineers, of Eugene, to document a project that will remove the damage and replace it with new, pre-cast, rail sections that will look almost exactly the same as the originals. They will just be stronger. And the reinforcement steel will be “tied” together electrically, so that ODOT can connect the rail to the cathodic system and assure it doesn’t crumble away. AND, because the new rail and sidewalk are stronger, and meet code, we get to remove the lovely flex-beam!