Third Biennial Report of the Oregon State Highway Commission Part 22

Both of the above mentioned sections are Post Road Projects.

Negotiations with the U. S. Public Roads Office are under way for the grading of the Cow Valley-Brogan Road, and the Burrell-Vale Project will be submitted within a short time. It is hoped construction will begin early in 1919.

Survey of John Day Highway--Cow Valley-Brogan Section

During October and November, 1918, the State Highway Commission made a location survey of a 9.85 mile section of the John Day Highway between Cow Valley and Brogan. The line follows in the direction of the present road, but marked departures from the location were made in several places. Plans for this work are about fifty per cent complete. R. H.

Coppock, locating engineer for the State Department, was in charge of this work.

Survey of the Central Oregon Highway--Burrell Ranch-Vale Section

A survey is in progress on the section of the Central Oregon Highway between Burrell's Ranch and Vale. This line will follow along near what is called the Post Hill road, and will be about seven miles in length.

Immediately upon completion of the field work, the plans will be rushed in order that early action may be taken by the U. S. Office of Public Roads. The State Commission's 1919 construction program includes this section.

The survey is in charge of R. H. Coppock, locating engineer.

Reconnaissance Survey of Central Oregon Highway and Jordan Valley Road

During April, 1918, a reconnaissance survey was made by M. O. Bennett, division engineer, for the Department, over the routes between Burns and Vale for the purpose of establis.h.i.+ng a definite route for the Central Oregon Highway. This investigation resulted in the choice of the river route by the State Highway Commission. The route as selected goes direct from Burns to Crane, thence down the Malheur River through Riverside, Juntura and Harper to Vale.

In November, 1918, a reconnaissance survey was made by the State Department for the purpose of establis.h.i.+ng the most feasible route between Jordan Valley and Vale and Ontario. This report has not yet been submitted to the Commission, but the findings seem to favor the Sucker Creek Route. This survey was made by Manche O. Bennett, division engineer.

MARION COUNTY

Salem-Aurora Paving

One of the first paving projects to come up for consideration by the State Highway Commission was that of the Pacific Highway between Salem and Aurora in Marion County. Upon investigating this project, it was found that rural mail was carried over practically the entire distance between Salem and Aurora. This fact made the improvement of this road subject to Federal Aid, and as very few sections of State Roads west of the Cascade Mountains will qualify for Federal Aid, it was considered advisable to use some of the Federal money available to the State in the improvement of this section.

With a view to securing the approval of this project by the Federal Office of Public Roads, and to undertaking the construction during the 1918 season, the necessary surveys were made in January and February, 1918, and the plans submitted to the Office of Public Roads in March, 1918. The final approvement by the Government was received June 15, 1918, and on June 25 proposals for the construction were received and opened. The lowest bid received was from Warren Construction Company, Portland, Oregon, but as it was in excess of the State Highway Engineer's estimate, and in excess of the available funds, all bids were rejected.

[Ill.u.s.tration: INTERCOUNTY BRIDGE OVER THE WILLAMETTE AT SALEM. BUILT BY MARION AND POLK COUNTIES IN 1917 AND 1918. COST $250,000.00. TOTAL LENGTH 2,220 FEET.]

The work would have then been started by the Highway Department with State forces, but it was just at this time that the shortage of labor, materials, transportation facilities, etc., became serious, and the Federal Government called for curtailment of road construction, and the Highway Commission was forced to order the discontinuance of preparation for this paving, as well as for all other proposed work in the State.

Now, that Peace is in sight, there is every reason to believe that the Highway Commission will order that construction begin on the Salem-Aurora Paving at the very earliest date, and its completion may be looked for during the 1919 season.

This paving is to be sixteen feet wide with a two-foot rock shoulder on each side. The type will depend upon the bids received. The paving will start about four miles north of the city limits of Salem and extend to the Marion-Clackamas County Line, just north of Aurora, the total length being eighteen miles. It is estimated that this work will cost $360,000.00.

The Salem Bridge

The new bridge over the Willamette River at Salem, designed and built under the supervision of the State Highway Department, is one of the largest strictly highway bridges erected in the United States in 1918.

This structure has a total length of 2,220 feet, and consists of 352 feet of reinforced concrete approach on the Marion County end, six steel spans over the river aggregating 885 lineal feet, and 780 feet of high cla.s.s pile trestle approach on the Polk County end.

To provide for the river navigation, the U. S. Engineers required a minimum horizontal clearance normal to the channel of 120 feet and a vertical clearance of at least sixty-six feet above low water, in case a high level type of bridge were adopted. After careful study it was decided to construct a high level bridge of the deck type, and to carry the pony channel span on cantilevers projecting from the adjoining spans, giving an arch effect over the channel. By this type of construction, a clear distance of about 145 feet between channel piers was obtained.

To minimize the cost of fabrication and erection of steel, four spans were made practically the same. The east span was necessarily shorter than the typical ones, since otherwise it would place the channel opening too far across the river. This span is not so deep as the adjoining one, and the difference in height is made up by means of a rocker under the small span, which, of course, also serves the purpose of movable shoes. The channel span rests on cast steel rockers on one end, which are carried by a shelf on the cantilever panel. The opposite end of the span was pin connected.

Previous to the design of the bridge, wash borings were made, which indicated in a general way that the bed of the stream was composed of a few feet of gravel, underlaid with sand for a considerable depth. It was accordingly decided to carry the foundations down below the probable point of future scour, and carry the loads entirely upon piling. The two channel piers were sunk about thirty-five feet below low water.

The west approach is carried on fir piling treated in an open vat with carbolineum to a temperature of about 220 degrees F.

Lumber being comparatively cheap, the entire roadway deck of the bridge and wooden approach is composed of fir, three by seven inches and twenty-six feet long on edge, spiked together, thus projecting a foot outside the curb on either side, the roadway being twenty-four feet between curbs. An asphaltic wearing surface three and one-half inches thick effectively waterproofs the wood, and the small interstices between the pieces will allow sufficient circulation of air to preclude any possibility of attack of dry rot. The ends of the floor members were painted with hot carbolineum, as were also the wooden members contiguous to openings in the floor occasioned by expansion joints between spans.

The two five-foot concrete sidewalks are carried on brackets beyond the trusses. The curbs serve as reinforced concrete beams to carry half the sidewalk load to the trusses, there being small concrete struts extending up from the top of the top chords at panel and midpanel points. Between the bottom of the curb and the top of the wooden floor is a three-quarter-inch cus.h.i.+on of "Sarco." Since the bridge is on a grade, it was necessary to precast this in sheets the width of the curb.

When the material hardened, it was rolled up in convenient lengths and placed. It will thus be possible in the future to renew the wooden floor with comparatively little difficulty, although it is believed that the wood floor base, protected as it is now, should last at least fifty years.

On account of the rather extreme length for pony trusses of the channel span, 123 feet between end pins, it was decided to tie the trusses together, and this was accomplished by means of two arched lattice struts placed each twenty feet and six inches from the center of the span.

A final coat of battles.h.i.+p gray paint was applied to the steel work, and has evoked considerable favorable comment, being an innovation from the black paint commonly used in this part of the country.

The bridge was built by the Coast Bridge Company and Robert Wakefield of Portland. The cost of the structure complete was $250,000.00, of which Marion County paid approximately $200,000.00 and Polk County $50,000.00.

The engineering cost for the work is remarkably low. It includes surveys, borings, inspection of cement and steel fabrications, resident engineer's salary, cost of design, blue prints and supplies and stenographic work, and amounts to $4,600.00, or about one and eight-tenths per cent of the total cost.

Surrey--Salem to Jefferson

A reconnaissance between the city limits of Salem and the Linn County Line (Santiam River) just south of Jefferson, was made in the spring of 1918, and the following facts developed, as regards the comparison of three possible routes between these points:

Via Turner and Marion: Length, 22.5 miles.

Railroad grade crossings, 5 with main line of Southern Pacific.

Bridges, 9.

Overflow, long stretches.

Light grades--very little rise and fall.

Via Liberty and Ankeny Hill: Length, 18.6 miles.

No railroad crossings.

Bridges, small.

Undulating steep grades--heavy work to cut to 5 per cent or extensive alignment changes involving added distance.

New right of way required through valuable orchard property.

Present road macadamized or graveled entire length.

Jackson Hill Route: Length, 17 miles.

No railroad crossings.

Bridges, small.

Five per cent grades.

Good alignment. Low summit obtained by alignment change going to the east of Jackson Hill, involving two miles of new construction.

Right of way required--unimproved except in one instance.

Direct route.

Present road macadamized or graveled except for five miles.

A detailed survey was made over this so-called Jackson Hill route, and its advantages caused the Highway Commission to adopt it as the route of the Pacific Highway between these points. It is estimated the cost will be $109,000.00 to complete the subgrade, and it is expected this project will be commenced in 1919.

MORROW COUNTY