The valves were completely assembled by May 21, 1955, except for final adjustments and fitting of the seals. Beginning June 4, the valves were used as bulkheads to close the laterals of the penstock during the hydrostatic test of schedule A. During the test each valve was checked for packing gland and flange leakage. The flange connection between the unit 1 valve and the penstock connector developed a considerable leak, and on October 17, 1955, this joint was broken revealing a damaged rubber seal. The contractor replaced the seal and rebolted the joint. From June 10 to December 2, 1955 the contractor installed the penstock sections on the downstream flange of the butterfly valves, adjusted all packing glands that had leaked during the hydrostatic test of the penstock, and began realining the valves to the penstock flanged sections. When the valves were bolted to the penstock section, a gap developed between the valve base plates and the bearing surfaces of the valve legs. The flange joint was broken and the butterfly valves were jacked until the two flange faces were parallel, then the gap between the base plates and the valve legs was filled with shims. With the flange faces parallel and the valve legs resting evenly on the base plate shims, the jacks were removed and the flange was rebolted. This method of alinement worked very well, and after the valves were placed in service no vibrations were ever noticed. The work of shimming the valve base plates was completed on February 17, 1956. On December 5, 1955, the contractor began filling the penstock for the hydrostatic test of schedule B, with the valves being used again as bulkheads for the penstock laterals. Leaks again developed through many of the packing glands and through the joint between the valve connector and penstock on unit 1. On December 6, the contractor began removing the outer half of the crank housing covers in order to inspect and adjust the packing around the valve drive stems. Details of the difficulties experienced with the valves during the hydrostatic test, and their solution, are given in a field trip report included in the final construction report (see bibliography). Crews began reinstalling the crank housing covers on December 17, 1955, and completed the work on January 5, 1956. Final adjustment and scraping of the seals was begun on March 27, and all work was completed on March 29 except the repair of the connector to penstock flange on unit 1 which was subsequently done between August 20 and September 8, 1956. After the valves were placed in operation, the measured total leakage around all four valves was about 25 gallons per minute. (d) Controls for 186-Inch Butterfly Valves.-- The hydraulic controls for the 186-inch butterfly valves consist of a control cabinet for each valve and piping which connects each cabinet with the valve operating cylinder. The controls are located along the f-line of the generator floor at elevation 5397.50. The controls were furnished by Premier Gear and Machine Works, Portland, Oreg., under invitation No. DS-4108. The contractor began the installation of the controls on February 10, 1956, with a crew of five pipefitters. The unit 4 installation was completed on February 28 and unit 3 on March 5. No difficulties were experienced except that while greasing the unit 3 valve from the control cabinet, the high-pressure grease pump body casting was broken. The contractor returned the pump to the supplier and subsequently installed another pump in its place. The installation work on units 1 and 2 was completed on March 13. On March 8, the contractor began testing the piping in units 3 and 4, and during this testing a number of leaks developed in the piping within the control cabinets. The supply contractor was notified of these leaks and made arrangements for Palisades Contractor's pipefitter crew to seal-weld the fittings. All work was completed on May 15, 1956. 264. 150-Ton Crane. The 150-ton powerplant crane was furnished by Moffett Engineering Co., Albany, Calif. under invitation No. DS-3778. The crane was erected and tested by Palisades Contractors under item 155 of specifications No. DC-3675. The crane was received on the project May 25, 1954, and stored temporarily in the contractor's storage yard. During this period the trolley, trucks, and all electrical equipment were protected from the weather by a temporary shelter constructed of used plywood and canvas. On October 11, 1954, the contractor began the assembly of the crane. The trucks, girders, and miscellaneous parts were bolted together and installed on the crane rails at elevation 5440 in the powerplant. The trolley, safety rails, ladders, hoist drums, and electrical cabinets were also installed at this time, but no alinement or final checks were made. The crane was pulled to the north end of the powerplant, where a plywood shelter was built to house the crane during the winter months. All critical parts were greased and further protected by canvas. No further work was done until the job opened up in the spring. During the latter part of April 1955, the contractor completed the installation of the crane. All shafting and motors were checked for proper alinement, as well as all gears for proper mesh. While servicing the bridge brake a crack was discovered in the brake master cylinder. The contractor brazed the casting to expedite using the crane for the turbine erection. The permanent repairs to the brake assembly were made under purchase order. This completed the work required by the contractor except for testing, which was delayed until early in 1956. The crane was used extensively during the summer of 1955 and early winter of 1955-56 for erection of the turbine embedded parts and the placement of second-stage concrete. The only difficulty encountered during these operations was caused by an undersize bushing in the auxiliary hoist gear case, which was repaired under extra work order No. 22. The acceptance tests specified in the crane supply specifications, invitation No. DS-3778, were much more thorough than the erection contractor had to perform under item 155 of specifications No. DC-3675. The tests required in invitation No. DS-3778 which were not specified in specifications No. DC-3675 were performed by the contractor under extra work order No. 19. For use in testing, the contractor constructed test weights, as directed, from materials furnished by the Government. The crane, as furnished, failed to pass the acceptance tests outlined in invitation No. DS-3778 for the following reasons: (1) The mechanical load brake on the main hoist would not stop the load; and (2) the speed control, in the lowering direction, did not meet the specifications. A number of modifications and retests were made before final acceptance of the crane, all of which were performed as extra work. The final retest was made with rated load and consisted only of load brake and speed-control tests. The action of the load brake was satisfactory, but the speed control still did not completely meet the requirements. However, the characteristics of the electrical resistors are such that the hoist cannot be operated on any intermediate point over 15 seconds; thus it is necessary to inch the load for any hook speed other than full speed. For the above reason, a recommendation that the crane be accepted was made to and accepted by the Denver office. The required modifications to the crane were performed under extra work orders No. 2, 5, 6, 19, 22, 25, and 28, and three purchase orders. 265. 5-Ton Machine Shop Crane. - The 5-ton machine shop crane for the powerplant was furnished by the Stryco Manufacturing Co., San Francisco, Calif. under invitation No. (D)63,668A, and was erected by Palisades Contractors under item 155 of specifications No. DC-3675. The crane was shipped in two parts, the bridge assembly and the trolley. The erection was simply a matter of setting the bridge assembly on the crane rails and attaching the trolley. The trolley, which consists of the hoist motor with gear reduction and brake, drum, and travel sprocket, hangs below the main beam of the bridge and is supported by wheels which ride the upper side of the lower flange of the beam. Both the bridge and trolley travel are manually operated. The crane was tested with a test load of 6-1/4 tons. The hoist handled the load easily and the brake worked very good. The electrical motor controls also operated satisfactorily and had good inching characteristics. 266. 5-Ton Gantry Crane. The 5-ton gantry crane, to handle the draft tube gates, was furnished by Crane Hoist Engineering Corp., Los Angeles, Calif., under invitation No. DS-3906, and was erected by Palisades Contractors under item 155 of specifications No. DC-3675. The crane was shipped assembled except for the main cantilevered beam at the top. Assembly consisted of bolting this beam in place, reeving the cable, and casting the concrete counterweight. The crane was tested at 125 percent rated load. The hoist handled the load easily, and the operation of the load brake was excellent. A minor item of extra work was performed under order for changes No. 1. 267. 30-Ton Control House Crane. The control house crane was furnished by Maris Crane and Hoist Co., Philadelphia, Pa., under invitation No. DS-4360, and was erected by Palisades Contractors under item 155 of specifications No. DC-3675. The erection of the crane was under the supervision of an erecting engineer from the supplier. The crane received considerable damage during shipment, the worst of which was to the hoist gear case. The repair work was done by Palisades Contractors under extra work order No. 34 and the cost was backcharged to the railroad. The east end of the control house was completed, except for the brick walls, before the crane erection was started, so temporary extensions had to be added to the west end of the crane beams to support the crane until it could be moved onto the permanent beams in the completed part of the building. The bridge was assembled in the contractor's work area and transported to the control house as a unit on June 25, 1957. The bridge assembly was placed on the temporary beams, the trolley installed on the bridge, and the assembled crane pulled into the completed part of the control house. The bridge-brake master-cylinder plunger was found to be broken and the release springs were so weak that the brake could not be adjusted to release properly. Replacement parts were furnished by the supplier and installed by Palisades Contractors. The assembly of the crane was completed without difficulty on July 10, 1957. After erection, the crane was used for erection of the outlet gates. During this operation a knocking noise developed in the trolley travel gear box; inspection disclosed a defective bearing which was replaced by the supplier. The work required to make this inspection and install the new bearing was done by the installation contractor. The crane was tested by Palisades Contractors on September 19, 1957, as outlined in the supply specifications, and all tests which were not covered in paragraph 199 of specifications No. DC-3675, were paid for under purchase orders. The main test was conducted under a job order. However, the bridge jog readings had to be postponed because of the faulty bridge brake, and the trolley travel readings had to be rerun because of binding between the trolley wheels and the end frame. The retest was performed on May 15, 1958. The corrective work required on the trolley wheels and other necessary modifications were performed under extra work orders No. 30 and 34 and six purchase orders. 268. Ring- Follower and Outlet Gates. (a) General.-- Six pairs of 7-foot 6-inch by 9-foot 0-inch outlet gates are installed in the outlet works control house. Four pairs are connected to the outlet tunnel and two pairs to the power tunnel (fig. 187). One guard and one service gate in tandem constitute a pair. In both outlet pipes 3 and 4, there is installed a 96-inch hollow-jet valve with a 96-inch ring-follower gate immediately upstream of each valve serving as a guard gate. See figure 84 for general installation of the gates. The ring-follower gates were supplied by Goslin-Birmingham Manufacturing Co., Birmingham, Ala., under invitation No. DS-4200. The outlet gates were supplied by the same company under invitation No. DS-4073. The controls for the ring-follower and outlet gates were supplied by Union Steel Manufacturing Co., Seattle, Wash., under invitation No. DS-4357. The ring-follower and outlet gates, including the controls, were installed by Palisades Contractors under item 152 of specifications No. DC-3675 and involved 1,723,481 pounds of material. The actual installation work was subcontracted to American Pipe and Construction Co., Portland, Oreg. (b) Installation of 7.5- by 9-Foot Outlet Gates.--American Pipe began bolting the gate bodies for outlets 7 and 8 to the penstock on August 2, 1955, using a millwright crew of three men. Alinement of the bodies started on August 5. Of several methods tried for alining the gate bodies and maintaining the alinement during embedment in concrete, the final and best procedure was as follows. The bodies were placed on steel supports on elevation, in correct alinement, and on station by using surveying instruments; plumb bobs were suspended from the top of the bonnets to the invert of the bodies, and the bodies were pulled into position both transversely and laterally by establishing a plane between the bronze seal faces and bronze guides and the plumb line with an electric micrometer. The bodies were plumbed into a plane with the top of the bonnets leaning downstream about 1/32 inch. In order to move the bodies, the contractor welded tiedown bars to the bodies and bonnets and attached the bars to hairpin bars embedded in the concrete. By pulling on the bars the gates could be racked into position. After the seal faces were within about 0.015 inch of a true plane, the contractor made the first concrete placement which embedded the bodies about 6 inches. The initial embedment Figure 187. --Looking downstream from the outlet of the power tunnel, showing the 7.5 by 9-foot outlet gates 7 and 8 which have been placed in position to bypass served to take all slack from the tie-down bars and also supported the bodies firmly. The bodies were realined at this time and then were completely embedded in concrete. If, after embedment, a 0.005-inch feeler gage could be inserted between the gate leaf and gate body, the contractor ground the bronze seal face of the body until contact was obtained within 0. 005 inch. Before embedding the gates, the lubrication grease piping to the bronze seal faces was installed and tested at a pressure of 2, 000 pounds per square inch. The alinement of the gate bodies and bonnets for outlets 7 and 8 was completed on October 15, 1955. Installation of the gate leaves for these outlets began on February 17, 1956. The contractor fabricated a tripod for handling the gate leaves and began the process of fitting the leaves to the bodies within 0. 005 inch by grinding the body seal faces. On February 28, the contractor began disassembling the hoists in the control-house area. The work of fitting the leaves and cleaning and installing the hydraulic cylinders on outlet gates 7 and 8 was finished on March 30, 1956. A temporary installation of the controls for outlet gates 7 and 8 was necessary because the permanent power control cabinet location was adjacent to outlet 5, and the outlet works from outlets 1 through 6 had not yet been constructed. The temporary control system was installed during the period May 29 through June 12, 1956, and the gates were operated for the first time on the latter date. Work was resumed on January 9, 1957, with the installation of the grease piping in outlet gate bodies 1 through 6. Only one craftsman was employed until February 1, 1957, when another man was employed and the work of cleaning the gate bodies began. The installation of the bodies began on March 27, and by April 24 about 10 men were working on the gate installation with one crew alining and plumbing the gate bodies and another crew disassembling and cleaning the hydraulic cylinders in the storage area. The installation of the gate leaves and fitting of the leaves to the body seals on outlets 1 and 2 was begun on May 14, and the installation of the cylinder hoists started on May 24. Final alinement of all the gate bodies was completed on May 21, and fitting of the gate leaves to the body seals was completed on June 10. The crews stopped working on the outlet gates July 1 and concentrated their activities on the ring-follower gates and hollowjet valves. The work of installing the hydraulic cylinders was resumed on September 30 and completed on October 9, 1957. Three pipefitters began the installation of the ring-follower and outlet gate control cabinets, and piping from the cabinets to the hydraulic cylinders, on October 21, 1957, and completed the installation and began testing the control system on December 13. The high-pressure oil lines installed by the contractor and the control cabinet piping developed many leaks, and the contractor worked until January 8, 1958, testing and repairing the leaks. No more work was done until February 27, when the crew began installing additional vents in the high-pressure line and seal-welding the fittings in the headers and the cabinets. Work continued intermittently until July 11, 1958, when the installation was completed. (c) Installation of Ring-Follower Gates.-- The contractor began cleaning the ring-follower gate sections on May 15, 1957, in the storage area. Installation and alinement of the gate bodies started on May 25 and was completed on June 21. The hydraulic cylinders were completely disassembled and cleaned, the work being completed on June 26. The installation of the cylinders was started the next day. The contractor used the same procedure for alining and plumbing the gate body parts as was used in the installation of the outlet gates. After embedding the gate bodies the leaves were installed and the body seals were ground until the leaves contacted the body within 0.005 inch. The work of fitting the leaves started on July 1 and continued until August 23. The crews resumed work on October 10 and completed the work of fitting the leaves to the bodies the following day. The crews then began the installation of the cylinders, which was completed on November 6, 1957. The installation of the ring-follower gate controls was done in conjunction with the installation of the outlet gate controls. Certain necessary modifications and other items of extra work were performed under extra work orders No. 29, 30, 31, 32, 34 and several purchase orders. 269. Hollow-Jet Valves. (a) General.--One 96-inch hollow-jet valve is located in each of outlets 3 and 4 in the outlet works control house. Each valve is used for water regulation, together with the ring-follower and outlet gates. The valves were furnished by West Winds, Inc., San Francisco, Calif., under invitation No. DS-4186. The valves were installed under item 154 of specifications No. DC-3675 by Palisades Contractors and involved 288,574 pounds of material. Palisades Contractors subcontracted the actual installation work to American Pipe and Construction Co., Portland, Oreg. For general installation see figure 84. (b) Installation.-- The American Pipe millwright crew began work on the valves on July 1, 1957. A cradle was fabricated to support the valve sections, and all sections of the valves were disassembled, cleaned, and reassembled. The work on the valves was done intermittently by the same crew which was working on the ring-follower and outlet gates. After the needle assembly and needle-support assembly were cleaned, the two sections were assembled together. The valve bodies were then cleaned, and the conduit adapters were bolted to the valve bodies. The contractor moved both valve bodies from the storage area on September 18, 1957 and installed them in the vertical position on the trunnion bearings. The two needle assemblies were moved to the control house. The valve A needle was placed on jacks in the valve body and the valve B needle was placed in a temporary cradle support. The valve B needle was installed in the valve body the following day. As valve A was being lowered into position it became stuck in the valve body, and investigation revealed that there was insufficient clearance between the needle and body in both valves. The contractor ground the needle bushing and gland to the proper dimensions. On April 8, 1958, valve A was turned to the horizontal position, and crews began the installation of the conduit and conduit adapter. At the same time the installation of the valve control mechanism was started. All work was completed on April 29. On April 30, the valves were closed and checked for leakage, the manifold having been filled with water for curing of the outlet manifold concrete encasement. Neither valve leaked any water. |