ect. RR 2. IMPROVEMENT OF REDWOOD CREEK, CAL. During the year a contract was entered into with J. C. Franks for dredging this creek to obtain the channel required by approved projThe contractor experienced considerable difficulty in finding a place for disposing of material, and work progressed slowly. Up to June 30, 1911, a total of 68,650 cubic yards had been excavated at a unit price of 9.73 cents per cubic yard. Dredging of this creek being in progress at the end of the year, there has been no deterioration. Deterioration in the future may be expected, and it is proposed to use the balance remaining after completion of present contract for maintenance as needed. Estimate of additional funds required. Amount that can be profitably expended in fiscal year ending June 30, 1913, for maintenance of improvement.... Contract dated January 31, 1911, for dredging 100,000 cubic yards of material from Redwood Creek, Cal.: Rate: 9.73 cents per cubic yard. Name of contractor: J. C. Franks. Date of commencement: April 24, 1911. Date of completion: Not completed at end of year. Date of approval: February 8, 1911. Date of expiration: May 23, 1911. 1 Exclusive of the balance unexpended July 1, 1911. Of this amount, $357.34 was returned to the Treasury. COMMERCIAL STATISTICS. Vessel classification. It has been impossible to obtain any exact data as to the classification of the vessels using this stream. IMPROVEMENT OF OAKLAND HARBOR, CAL. At the beginning of the year a dredging contract was in force with the San Francisco Bridge Co. for dredging in this locality to obtain a channel 300 feet wide and 25 feet deep from Fallon Street to the tidal basin, and a 300-foot channel 17 feet deep around both sides of the tidal basin. This contract was completed July 20, 1910. The price paid was 18.8 cents per cubic yard, place measurement, and the quantity of material removed during the fiscal year was 102,785 cubic yards. In addition, 125,400 cubic yards were allowed for overdepth dredging, and paid for at 9.25 cents per cubic yard. Upon completion of contract the sum of $9,400 was paid contractor as retained percentages. The total amount removed under this contract was 2,148,838 cubic yards. On November 15, 1910, a new contract was entered into with this same company for dredging about 1,289,200 cubic yards of material to deepen the present 25-foot channel to 30 feet deep at low water to a width of 300 feet and extending from the 30-foot contour in San Francisco Bay to the Webster Street Drawbridge. This contract was still in force at the end of the year. The price paid was 11.4 cents per cubic yard, place measurement, and the quantity of material removed under this contract during the fiscal year was 458,993 cubic yards. On December 15, 1910, a contract was entered into with Frederick C. Roberts & Co. for placing the three Government drawbridges across the tidal canal in satisfactory condition for operation of their draws by electricity for a lump-sum price of $16,100. Owing to delay in obtaining certain electric motors from the East the work of completing this contract was somewhat delayed. Under this contract six systems of automatically operated highway gates were installed with their equipment; all old machinery was overhauled, cleaned, and put in good condition; the required electrical machinery, wiring, etc., was installed; and a control house was installed on each bridge. The contractor was paid a total of $12,636. The contract is all completed except the installation of two 30horsepower motors, two 15-horsepower motors, one 10-horsepower motor, and incidental minor connections. In addition to the above contract, the flooring on the Fruitvale Avenue Bridge was patched and finally renewed at a total cost of $176.48. The reflooring of the Park Street Bridge was in progress at the end of the year. Work to the extent of about $975 had been completed. In addition, some extra work was done by Frederick C. Roberts & Co. at a total cost of $225. For further particulars as to transfer of these bridges to local authorities, see page 2350, Report of the Chief of Engineers, 1910. The deterioration in the Government works at this locality consists of shoaling in the main ship channel and natural deterioration of the three bridges. From recent cross sections of the channel it is estimated that the deterioration that has taken place in the ship channel since the completion of prior contracts amounts to about 753,000 cubic yards west of Webster Street Drawbridge and about 1,500,000 cubic yards east of this bridge and around the tidal basin. The estimated cost of removing this shoaling is 10 to 11 cents per cubic yard. The rapid shoaling, especially in the channels around the tidal basin, renders the question of maintenance very serious. Certain shoaling was to be expected, as both banks of the tidal basin are of soft flowing mud, and the center flat is kept in more or less agitation by vessels anchored on this flat. In the waters of San Francisco Bay material is almost constantly carried in suspension, and would naturally deposit in the tidal basin. As the dredging is continued, however, it is possible that the shoaling may become less, due to flatter slopes of the banks. The desirability of water front in San Francisco Bay and adjoining waters makes it worth while to attempt to maintain these depths. As the three bridges have been put in good repair and will soon be turned over to the local authorities for operation as drawbridges, maintenance, and repairs, there will be no further charge to the Government on their account. COMMERCIAL STATISTICS. Season of navigation.-Opened, January 1; closed, December 31. Amount that can be profitably expended in fiscal year ending June 30, 1913, for works of improvement and for maintenance.. 1 $100,000 |