Puyallup Avenue Bridge Slideshow

  • By John Caldbick
  • Posted 9/05/2013
  • HistoryLink.org Essay 10460

With advances in the smelting and working of steel, riveted and welded geometric shapes could be constructed that distributed the various forces to which a bridge is subjected, adding great strength and allowing them to become longer than previously possible. Steel-truss bridges first appeared in the United States in the 1840s. Between about 1870 and the mid-1920s, truss bridges were the most common type built in this country, and dozens of variations on the basic theme were devised. These designs were often developed by engineers working for railroad companies, which needed bridges capable of carrying very heavy loads.

The Puyallup Avenue Bridge  incorporates three different truss styles. The westernmost truss section, located in Tacoma, is a 193-foot-long Baltimore petit truss, a variation of the basic Pratt truss with additional diagonal members in the lower sections of the superstructure. The three, linked central spans that cross the river itself, each 252 feet long, are all Pennsylvania petit trusses, a modification of a Pratt-truss design, with additional diagonal members and a parabolic, as opposed to straight, top chord (the topmost horizontal members of the supporting superstructure). The eastern truss segment, located in Fife, is a Warren truss, with bracing that forms alternately inverted equilateral-triangle-shaped spaces along its 114-foot length. It is slightly modified from the "pure" Warren form by the addition of vertical members within each triangular section.

Much of the impetus to build a highway running the length of America's West Coast from the Canadian to the Mexican borders came not from government, but from  automobile enthusiasts in the three states the road would travel through -- Washington, Oregon, and California. Although The New York Times credits A. E. Todd of Victoria, British Columbia, with first publicizing the idea, success has many fathers, and a number of other early auto visionaries worked to make the Pacific Highway a reality.

In Washington state, the government was notably slow to embrace the inevitable dominance of motor vehicles, but as early as 1899 private citizens, notably Samuel Hill (1857-1931), son-in-law of railroad magnate James J. Hill (1838-1916), joined together to form the Washington State Good Roads Association. It was organized to promote, as its name states, the construction by government of "good roads." Hill envisioned  "a highway built through British Columbia down our own coastline, clear to Mexico and it’s going to be a hard surfaced road" ("Samuel Hill celebrates ... ").

In 1910 a more specialized group, the Pacific Highway Association of North America, was formed in Seattle for "the promotion of the construction of an international highway along the Pacific Coast from Canada to Mexico" ("Autoists Organize Highway Association").  In that same year, Washington Highway Department Commissioner  H. L. Bowlby (later to become chief engineer of the Oregon Department of Highways), spent $40,000 on a preliminary survey for the proposed route, and officials in Oregon and California soon followed suit.

Despite this early enthusiasm, finishing the entire Pacific Highway proved a prodigious slog. Work with the ultimate goal in mind started in 1913, and ten years later Oregon finished its portion of the road, becoming the first state west of the Mississippi to have a paved highway running its entire length. In many places, the Puyallup River crossing being one, bridges were completed before the roads that they would serve were paved and opened. There does not seem to be a specific date recorded when the entire Pacific Highway was deemed "complete," but segments were still being added and joined together well into the late 1920s. In fact, the Puyallup Avenue Bridge sat unused for more than eight months while paving was finished on the Pacific Highway between Seattle and Tacoma.

The Puyallup Avenue Bridge (also known as the Eells Street Bridge and the Puyallup River Bridge) was designed by engineers of the Washington State Highway Department. The prime contract for its construction was awarded to Grant Smith and Company of Seattle, and the Federal government financed a little more than one-half the $665,000 cost. One condition of federal aid was that all materials used in the construction be made in America. The Wallace Equipment Company of Seattle was selected to fabricate the steel used on the project, including the various components of the truss sections of the span and the heavy girders that supported the reinforced-concrete roadway.

Preliminary work began with site preparation in the late months of 1925. A central plant was established on the banks of the Puyallup River near the construction site. Material barged down from Seattle, including the span's structural steel,  was offloaded here. Concrete to be used to build the bridge's approaches was mixed here as well, fed into buckets, then hauled by a small locomotive to the construction site, where the buckets were lifted by crane and their contents poured into prepared forms.

Among the first components of the bridge to be built were the concrete piers that would support the approaches on either side of the river.  Protective cofferdams were constructed to permit work in areas invaded by the river's waters.  Holes for pier footings were then excavated with clamshell buckets, forms built, and concrete poured. 

The designers and builders of the Puyallup Avenue Bridge faced three major obstacles -- the Puyallup River itself, dikes built along the shore for flood control, and railroad tracks that ran roughly parallel to the river on either side. To cross these obstacles three variations of  the truss-style bridge were used. These were linked to surface streets and to each other by sections made of reinforced-concrete.

Steel for the primary girders and truss sections of the Puyallup Avenue Bridge began arriving from Seattle by barge in March, 1926. Temporary wooden falsework was put in place to provide support while the concrete piers and steel truss segments were built. Men worked on both sides of the river, simultaneously preparing the east and west approaches to the main portion of the bridge.

Approaching from the west (Tacoma) side of the Puyallup River, a sloped concrete approach leads to a 193-foot-long Baltimore petit truss, a variation of the basic Pratt truss with additional diagonal members in the lower sections of the superstructure that add strength. The style was invented in 1871 by engineers for the  Baltimore & Ohio Railroad, and "petit" refers to the shorter additional bracing that is used. This section of the bridge carries traffic over railroad tracks that serve the industrial area of Tacoma that lies south of Commencement Bay.

Railroad tracks and dikes on the east (Fife) side of the Puyallup River are crossed by a Warren truss span with bracing that forms alternately inverted equilateral-triangle-shaped spaces along its 114-foot length. It differs from the "pure" form of the Warren truss only by the addition of vertical support members bisecting the triangular sections. This portion of the bridge is connected to the central span by a short concrete section of roadway and to the city of Fife by a long, reinforced-concrete ramp that terminates near the intersection of Eells Street and Milwaukee Way.

Building over water can be difficult and dangerous. Before work began on the construction of the three central sections of the Puyallup Avenue Bridge, a total of four massive concrete piers were poured to support the structure -- one on each shore and two embedded in the Puyallup River itself. Because the river is shallow at the site and thus impassable to sizeable vessels, the bridge could be built as a fixed span, with no need for sections that could be raised or pivoted to allow for boat traffic to pass.

On construction drawings, the five truss sections of the bridge were labeled (moving from east to west) A, B, C, D, and E.  "A" is the Warren truss on the Fife side of the river, "E" is the Baltimore petit truss on the Tacoma side, and "B," "C," and "D" are the three linked Pennsylvania petit truss segments that pass over the river.

Construction of the three central spans began on the west (Tacoma) side of the river, with Span D. Wooden falsework was build out over the river, the large longitudinal bottom girders supporting the bridge deck were put in place in sections, and the rest of the truss framework built in stages atop them.  These main girders provide the primary support for the roadbed and, tied directly to the bridge's steel superstructure, become an integral part of the truss design. The entire truss "unit" -- bottom, sides, and top -- all linked together by welds and/or riveting, distributes the weight of the bridge itself (the dead load), the weight of the traffic thereon and the stresses it creates (the live load), and the lateral and vertical forces (called static and dynamic loads) caused  by the wind. Expansion joints at set intervals were installed to permit minor changes in the bridge's length caused by seasonal temperature variations.

When Span D was substantially complete, the builders moved on to Span C, extending girders between the two mid-river  piers, then erecting the sides and tops of the truss structure. In this gradual way, the workers progressed across the river form west to east. Span B was last, and when it was completed the preparations for paving these three segments could begin.

Contemporary photographs indicate that each of the three center truss sections of the bridge took about six weeks  to construct. When the last was done, the Puyallup Avenue Bridge, while not quite complete, spanned the river from shore to shore. All that was left to do was removing the falsework, final paving, and minor detail work.

Among the last tasks for the bridge builders was the pouring of the roadway over the river and the final finishing of the bridge's curbing, sidewalks, and concrete railings. A latticework of steel reinforcing bar was laid down over the bottom chords of the central span and concrete poured from buckets maneuvered by large cranes.

Special attention was given to the railings, which the designers had specified should be smooth and have a finished look. The forms used to make them were made of high quality, tongue-and-groove boards, which were oiled before the concrete was poured to insure clean removal of the forms and a smooth surface on the railings.

All the major work on the Puyallup Avenue Bridge was completed by January, 1927, two months ahead of schedule and within budget. A dedication ceremony was held on the center span on January 8, 1927. However, significant stretches of the Pacific Highway between Seattle and Tacoma remained unpaved, and the bridge would not open to traffic until this was substantially completed more than eight months later.

When complete, the Puyallup Avenue Bridge was 2,833 feet long, with a 36-foot-wide roadway and five-foot pedestrian walkways on either side. It was, for its time, a graceful structure, with the long concrete approaches on either side leading to the three intricate central truss spans. The workmanship was excellent and the materials of the highest quality. The bridge was built to last, and lasted it has, for over 85 years (as of 2013).

But time and the elements have taken their toll. Steel has rusted, concrete has cracked, and in recent years restrictive load limits for the bridge have been necessary. Repairs and maintenance have become ever more costly, and the need for a robust commercial arterial across the Puyallup River, with direct access to Tacoma's industrial area and port facilities, has taken on increased importance as the area has grown far beyond what it was in 1928.

The City of Tacoma, which now owns the bridge and is responsible for its maintenance, has for several years been preparing for its eventual replacement. Although not all the funding is yet in place (2013), planning is well along. Replacing the entire span at once (at an estimated cost of $38 million, almost exactly 50 times the original price tag) has been deemed not feasible, and current proposals call for a three-step process, with the western portion of the bridge up to the first Pennsylvania petit truss section due to be replaced with a modern and striking looking cable-stayed span. In later years the rest of the bridge will be dismantled and replaced, bringing to an end a piece of Pacific Highway history that will by then have provided nearly a century of service.

The Puyallup Avenue Bridge in Pierce County crosses the Puyallup River and links Tacoma to the small city of Fife to its east. It was opened in 1927 as one of the last Washington segments of the famed Pacific Highway, which eventually ran unbroken from British Columbia to the Mexican border. As of 2013, the bridge had been in constant use for over 85 years. Linked by sections of reinforced concrete, Its five steel-truss spans cross dikes, railroad lines, and the Puyallup River and are part of a still-important arterial freight corridor that serves Tacoma's port and industrial areas.

 

Sources:

"The Pacific Highway," The New York Times, July 10, 1921 (http://www.nytimes.com/); "Autoists Organize Highway Association," The Seattle Times, September 20, 1910, p. 9; HistoryLink.org Online Encyclopedia of Washington State History, "Samuel Hill celebrates international peace and dedicates the Pacific Highway at Blaine on July 4, 1915" (by Richard Clark), and "Puyallup Avenue Bridge" (by John Caldbick), and "Politicians, officials, and members of the public dedicate Pacific Highway's Puyallup Avenue Bridge linking Tacoma and Fife on January 8, 1927" (by John Caldbick), http://www.historylink.org/ (accessed August  11-13, 2013).

Licensing: This essay is licensed under a Creative Commons license that encourages reproduction with attribution. Credit should be given to both HistoryLink.org and to the author, and sources must be included with any reproduction. Click the icon for more info. Please note that this Creative Commons license applies to text only, and not to images. For more information regarding individual photos or images, please contact the source noted in the image credit.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License
Major Support for HistoryLink.org Provided By: The State of Washington | Patsy Bullitt Collins | Paul G. Allen Family Foundation | Museum Of History & Industry | 4Culture (King County Lodging Tax Revenue) | City of Seattle | City of Bellevue | City of Tacoma | King County | The Peach Foundation | Microsoft Corporation, Other Public and Private Sponsors and Visitors Like You