Baker River Cable Stay Bridge, 1998
Mt. Baker Ranger District, Mt. Baker-Snoqualmie National Forest, WA
Satellite view of bridge location. (resolution insufficient to see bridge) View Larger Map
SPAN: 240' w/45' approach ramp
TRAVEL WIDTH: 6'
TOWERS: 38' tall, 14" x 14" ASTM A847 tube
ANCHORS: Sahale earth anchors (one side) and twin 1 3/8" rock bolts (one side)
CABLE STAYS: 1", 1.125", 1.250", & 2" ASTM A 586 Bridge Strand
|Baker River Bridge, 1998|
The Baker River Cable Stay Bridge is at the end of the Baker Lake Road, off the North Cascade Highway in Washington. It is the northernmost trailhead link of the 14 mile long Baker Lake Trail, an historic prospecting and lumbering route through old growth forest east of the Mt. Baker volcano. The bridge crosses the Wild and Scenic upper Baker River; a region subject to periodic violent flooding that has negated numerous previous attempts at bridging since 1900. The simple lines and low visual impact of this bridge perfectly complement the expanse of active river channel, towering old growth forest, and surrounding snow capped, craggy peaks.
1/2 mile upstream from the trailhead, the Baker River Bridge site is not
accessible to conventional construction equipment. The hydraulic
permit for the project allowed movement of an excavator up the river channel
for the purpose of excavating the footings, and for a small mobile crane
to assist with erection of the towers, but operation of equipment from
within the ordinary high water mark of the river was not permitted. Concrete
for the abutments and anchors was delivered to the site via helicopter,
and for ease of construction the bridge was designed to have maximum component
weight of 4000 pounds and length under 40'.
concrete volume (and expense) earth anchors were used on one side of the
bridge and rock anchors in freight car sized boulders were used on the
other. One anchor rock required through-bolting, which was achieved
by tunneling under it for access.
1998 Construction: Skyline and Carriage
Testing Rock Anchors with 60 Ton Jack