Siuslaw River Bridge

The Siuslaw River Bridge is being rehabilitated, concrete repairs with a cathodic protection system. Even with the containment it is a magnificent structure. I got to spend last night hanging under the bascule span and woke up to this view!

The lift span deck and sidewalks were rehabilitated by Advanced American Diving Services in approx 2005, which included replacing the steel grating deck and with a FRP hollow core composite and overlaid with a polymer filled aggregate finish. The sidewalks were also replaced with fiber reinforced recycled plastic lumber. I was the Project Manager for AAC on that contract.

I believe the Hamilton rehabilitation was mostly mechanical/electrical upgrades and were definitely needed. The system was original construction in 2005 and in bad shape when we performed the lift span improvements.

James: Regarding movable types, my comments:

Abt bascules are not a subcategory of heel trunnions. "Abt trunnion bascule" would be correct. Also, to my knowledge all heel trunnions are Strauss Heel-trunnions. Not sure anyone else ever built them.

For rolling lifts, I would call them "Scherzer type rolling lift bascule" I add the word "type" to the name, because many are not directly associated with Scherzer RLBC or successors Hazelet and Erdal.

There should be a category for Strauss trunnion bascules. These are those Strauss bascules which have two trunnions, but are not heel trunnions.

There should be a category for Strauss direct-lift bridges (type of vertical lift). This category could be called more generically "direct lift" since C. L. Strobel also had a direct lift design, although I don't think any examples survive on this planet.

Swing bridges are classified with two different descriptor categories. One is the type of bearing, which you have listed (center or rim bearing). However they are also categorized by whether they are "center pier" (ie the truss is symmetrical) or bobtail, (asymmetrical, counterweighted at one end)

I'd like to expand the list of categories for movable bridges. Right now, when editing a bridge, there's a simple pulldown menu for vertical lift, bascule, swing, etc. I'm thinking of expanding the menu to include the additional sub-types below. Do I have these organized correctly? Am I missing anything?

BASCULE

...Fixed trunnion bascule

......Chicago-type fixed trunnion bascule

......Page fixed trunnion bascule

...Heel trunnion bascule

......Strauss heel trunnion bascule

......Abt heel trunnion bascule

...Rolling bascule

......Scherzer rolling lift bascule

......Rall roller bascule

VERTICAL LIFT

...Span drive vertical lift

...Tower drive vertical lift

SWING

...Center-bearing swing

...Rim-bearing swing

Mike:Thanks for confirming the bascule type.

All: I noticed there was not a fixed trunnion bascule category on BridgeHunter even though there are rolling lift and heel trunnion categories, so I added a fixed trunnion bascule category that people can use if they know the bascule type.

Nathan,

Your assessment of the bascule is correct. The bridge is in fact a fixed trunnion bascule. It was designed by the Oregon State Highway Department, under McCullough.

The configuration of the bascule truss is identical to the other OSHD designed bascule bridges of the era (Isthmus Slough, Lewis & Clark River & Old Young’s Bay).

MG

Based on photos and HAER documents, this appears to be a Chicago type fixed trunnion bascule. Anyone know any different?

After what seemed like endless rehab/electrical projects, the Siuslaw River Bridge is finally scafoldless. I was finally able to get up close and get some decent photos. This is definitely one of Conde McCullough's finest designs. Three vastly different bridge types blend into a seamless beautiful structure.