filling the grout pipes. Unit 1 was grouted February 13, 1956, six sacks of cement being used, four for grouting the void and two for filling the grout pipes.

200. Grouting Equipment. The equipment used for drilling and grouting the cutoff curtains in the west abutment of the dam was as follows: One flat-bed truck, three diamond drills, one 12-cubic-foot vertical-shaft grout mixer, one 14-cubic-foot verticalshaft grout agitator, one water meter, one 6- by 2-1/2- by 6-inch grout pump, one 4by 2-1/2- by 4-inch grout pump (used as a water pump). The mixer and agitator were powered by air motors and were mounted on a skid platform constructed from steel angles and channels. The grout pump was also mounted on a skid platform. The material platform, approximately 9.5 by 6 feet, was also constructed from steel angles and channels and had a plank deck.

Two jumbos mounted on flat-bed trucks were used for drilling and grouting in the tunnels. The drilling jumbo had platforms from which the drills could be set up on the various hole positions. The grouting equipment consisted of two 6- by 3- by 6-inch duplex piston pumps, two 12-cubic-foot vertical-shaft grout mixers, and one 14-cubicfoot vertical-shaft agitator. These were mounted on the second jumbo. One flat-bed truck was used for hauling cement. During the time that backfill grout was being pumped, using the sand-cement mixture, the vertical-shaft grout mixer was replaced by a horizontalshaft pug type mixer.

201. Subcontractor's Forces. During the drilling and grouting of the cutoff curtains in the west abutment of the dam, the subcontractor's (Boyles Brothers) personnel per shift usually consisted of one foreman, one or two drillers, one pumpman, and one or two laborers. For grouting in the tunnels, the crew generally consisted of one foreman driller, one pumpman, and one or two laborers.

During the period that two holes were being drilled and grouted simultaneously in the power and outlet tunnels, the personnel generally consisted of one foreman, one driller, one pumpman, and two laborers per shift. The personnel per shift varied at times to suit the particular phase of the work being done.

H. Powerhouse Structural Steel and Masonry Installation
(Specifications No. DC-3675)

202. General. The structural steel insulated metal wall panels, and accessory materials for Palisades Powerplant were furnished by California Steel Products Co., Richmond, Calif., under invitation No. DS-3898. The steel was installed by Palisades Contractors under specifications No. DC-3675, item 127. Soon after beginning the installation, Palisades Contractors, sublet the work to William B. Willett Co., Sacramento, Calif.

The structural steel powerplant building framing consists of base plates, columns, framing, and girders extending from the generator floor at elevation 5397.50 to the top of the steel at elevation 5461.66. The framing, with brick walls, houses the powerplant generators. The stuctural steel also includes the girders and rails for the 150-ton overhead traveling crane in the generator room and the 5-ton trolley hoist in the powerplant machine shop.

Work on erecting the structural steel started on August 11, 1954, and continued until severe weather forced a work stoppage on November 29. Work was resumed on March 27, 1955, and continued until October 7 when work was again stopped. The remainder of the work was done in January 1956, with the installation virtually completed by January 26, 1956. For general installation see figure 103.

203. Structural Steel Installation. - Erection of the structural steel began with installation of some of the main column base plates. The plates were set at elevation 5397.50 by the contractor and checked by a Government survey crew. Base plates for columns F8, F9, F10, F11, F12, C8, C9, C10, C11 and C12 were installed before the first column was erected, whereas the other base plates were installed at the time of erection of the structural steel. All 24 base plates were installed and all but the F1 column base plate were inspected during 1954. Erection of the main columns started

September 16, 1954, using a power crane to erect the columns and handle the steel sections. The columns were mounted on the base plates and then braced to prevent possible toppling. Temporary erection bolts were used to position and support the steel sections; these bolts were later removed and permanent ribbed bolts (Dardalet) were installed. Although no special efforts were made to plumb the columns during erection, checks by Government surveyors revealed the plumb of the columns approached the 1:1000 allowance generally permitted for exterior walls and elevator shaft columns. The greatest variation from true plumb exceeded the 1:1000 allowable by only one-sixteenth inch.

The girders, purlins, beams, trusses, struts, and braces were installed along with the columns. In general, the steel sections matched very well.

The contractor started installing the permanent ribbed rivet head bolts on October 11, 1954, using a sledge hammer to drive the bolts. In areas where the structural steel restricted use of a hammer, a chisel was placed against the bolt head, and by striking the chisel the bolt was driven. These methods of driving bolts resulted in many deformed heads and rejected bolts, so the contractor finally employed a rivet gun for driving and this eliminated the difficulty. All of the c- and f-line columns except columns F1, F2, and F3, two of the end wall columns, and about 60 percent of the connecting steel had been installed and bolted with permanent bolts when work was stopped for the season on November 29, 1954.

Work was resumed March 7, 1955, with most of the initial activity concentrated on completing the steel from the 8-line to the 12-line. On March 24 the F1 base plate was installed, and on April 5 and 6 columns F1, F2, and F3 were installed. These columns had not been erected with the rest of the steel, because the wall supporting the columns was monolithic with the machine-shop floor and was to be poured at a later date. To continue erection, temporary steel column base plate supports were designed and installed by the contractor. During April, May, and June, most of the remaining steel was installed and welding of the roof beams was started. On April 25, 1955, the contractor began alining and leveling the 150-ton crane girder. The contractor started installing the machine-shop steel on July 17, and completed this work on August 1. Most of the work, including the alinement of the crane girders and rails, was completed by August 31, and work was begun on the eave strut angles, windowsills, metal wall panels, window frames, and miscellaneous accessory materials. All work was stopped on October 7, 1955. Various minor pickup details were performed from January 13 to January 26, 1956, when all the work was virtually completed.

Minor changes and extra work related to the structural steel erection were performed under extra work orders No. 21, 23, and 24, order for changes No. 10, and a purchase order.

204. Brick Masonry. - Brick masonry was constructed to form the exterior walls of the powerplant and to form the exterior walls of the outlet works control house. This is the first brick powerplant constructed by the Bureau of Reclamation. Construction began June 1, 1955, on the powerplant and was finished October 10, 1955. The control house brickwork was started August 5, 1957, and completed October 1, 1957.

Face brick was used for all brick veneer and for the exterior face of the walls, and common brick was used for the interior face of the walls and for the row of brick between the interior and exterior faces of walls. All brick walls, except brick veneer walls, were constructed of grouted brick masonry. The Government furnished the cement for mortar and grout. The contractor furnished all other materials, including bricks, mortar, grout, reinforcement, masonry anchors and anchor slots for anchoring brick concrete, brick wall tie anchors and studs for anchoring brick to structural steel, calking compound, cork for expansion joints, and all other related materials required for construction of the brick masonry.

Bricks in the interior and exterior faces of brick walls and brick veneer were laid with full head and bed joints of mortar. The interior joints of the brick walls were filled with grout. Bricks between the outer tiers of brick walls were placed or floated in grout poured between the two outer tiers. Each pour of grout was stopped at least 1-1/2 inches below the top of the tier and properly stirred. All face brick and all common brick were laid in stretcher bond courses. Brick masonry was reinforced with steel reinforcement, and anchored to concrete and structural steel by the use of metal anchoring devices and keys. Expansion joints were constructed in walls, and corkboard

was installed in these joints. Open expansion joints were calked with calking compound to provide tightly sealed joints. All brick were moistened thoroughly before being laid, and surfaces upon or against which the units were laid were thoroughly cleaned and moistened before the brick was laid. All joints between brick which are exposed to view were pointed to form concave joints before the mortar had taken its initial set. After the brickwork was completed, all surfaces exposed to view were cleaned thoroughly with a muriatic-acid solution applied with a stiff fiber brush. After all spots and stains were removed, the brickwork was rinsed thoroughly with clean water.

I. Factors Affecting the Prime Contractor's Progress
(Specifications No. DC-3675)

205. Weather. A prolonged drouth, creating exceptional weather for construction operations, favorably aided all construction for the year 1952. In the years following, precipitation stopped earthfill operations on the dam several times each season until cold weather forced the stoppage of all work. For the most part, cold weather was the greatest weather factor that hampered work on the powerplant, outlet works, intake structures, and tunnels. With the advent of snow and freezing weather, most of the work was stopped until the following spring.

206. Labor. No labor difficulties occurred during the 1952 construction season. On February 2, 1953 the electricians walked out; differences of opinion were settled on March 4, 1953. On September 22, 1954, a labor dispute by the ironworkers resulted in a work stoppage because of failure of the Union to reach a wage agreement in negotiations with Palisades Contractors; work was resumed September 28, 1954. In 1955 a labor negotiation for higher wage rates resulted in an increase averaging 8 cents per hour effective July 1, 1955. One walkout occurred in 1956. On August 23 all Union crafts left the job for various reasons; work was resumed on August 31, 1956. Three labor difficulties occurred in 1957 which involved walkouts of contractor's employees. Work stoppages were for short periods of time and occurred for various reasons. The labor supply was plentiful; consequently, the contractor did not suffer from lack of workmen.

207. River Diversion. - Difficulties in second-stage diversion of the river resulted in delays as discussed in section 143.

The power tunnel bulkhead gate could not be closed successfully after the diversion channel was closed, as the jacks used to raise the gate were unable to lower it completely in place. Closure was deferred until the whirley crane was constructed and the flow of the river had decreased in the fall of the year.

208. Failure of Palisades Outlet Manifold. The outlet manifold (fig. 168) failed on September 26, 1957, in the wye No. 1 while the hydrostatic tests were being conducted (see sec. 216). Details are given in a report to the Commissioner from the Assistant Commissioner and Chief Engineer, dated April 4, 1958, included in the final construction report (see bibliography).

J. Prime Contractor's Equipment (Specifications No. DC-3675)

209. General.

The major equipment used by the contractor on the job is shown below. A more detailed list, including makes of equipment, is given in the final construction report (see biliography).