At Pedro Miguel the east side backfill was completed in January, 1917, and the west side backfill in April, 1917. DRAINS FOR BACKFILLS. In order to provide more satisfactory drainage of surface water during heavy rains, a considerable amount of concrete drainage ditch was constructed, as follows: 1,800 feet on the east backfill at Pedro Miguel, in April, 1917; 750 feet on the east backfill at Miraflores, in April, 1917; and 2,000 feet on the west backfill at Miraflores in June, 1917. SPARE PARTS. During the year a committee was appointed to determine upon the proper mechanical and electrical spare parts to be held in stock for the locks, together with a determination of the maximum and minimum number of such spares which shall be carried on hand. Arrangements have been made to take over the Corozal cement shed for use in storing the heavy spare parts for the lock machines, as well as spare gates and valves. Thirty-nine United States requisitions were issued during the year, 24 of them having been filled to date, the material on the balance being in process of manufacture. PAINTING LOCK GATES AND VALVES. During the year all submerged valves, gates, fixed irons and steel work at Pedro Miguel lock were coated with Navy bituminous compound. The following is the report on the dates of completion of this work: Pedro Miguel lock.-All the work at Pedro Miguel, with the exception of the work on the interior of the miter gates and on rising stem valves Nos. 334 and 335, was done by the lock forces. The work on the interior of the miter gates was done by the American Bitumastic Enamels Company at the time the construction work on the gates was completed, and they also touched up this work at the time we had the chambers unwatered for our work. The work on rising stem valves Nos. 334 and 335 was done by the contractor in March, 1916. Navy Department bituminous solution and enamel were used in connection with our work on all parts except gate No. 51, on which Navy Department bituminous cement was used. Analyses of the solution, enamel, and cement follows: 50.. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61 62. 63. 64. 65. 66. 67 68. 69. 70. 71. 72. 73. The following shows the work in detail at Pedro Miguel: Miraflores locks.-The work at Miraflores locks was done by the American Bitumastic Enamels Company, under contract, with a five-year guarantee. All the cleaning of the parts, however, with the exception of the cleaning of the miter gates, was done by the lock forces. The contractor used its own product, analysis of which follows, this being taken from data submitted by it: |