Page:Final Report - The Columbia River Interstate Bridge.pdf/62

 (3) Machinery:

By section 31 of the Specifications, the United States Steel Products Company is required to replace any and every part of the machinery furnished by it which may prove defective within one year from the putting of the bridge into service, or prior to February 14, 1918. The machinery should receive regular care and inspection with special attention at all times to the proper lubrication of moving parts.

(4) Wire Ropes:

The attention of your Commission is particularly called to the maintenance of the wire ropes on the lift span. \Vith proper attention these should not require renewal for many years, but it is essential that they be protected from rusting. Your Engineers recommend that in the summer of 1918, when the weather is warm, that the ropes be thoroughly cleaned of their present dressing and then treated with some ﬁrst quality wire rope dressing made especially for ropes exposed to the elements and infrequently operated. Successive applications of dressing should be made as needed, so that rusting of the wires in the ropes may be entirely prevented. The ropes should be carefully inspected twice a year. early in the spring and late in the fall.

(5) Substructure:

The piers themselves are subject to practically no deterioration, although about ten years from this date it would be well to have them cleaned and painted with a wash of lime and cement. However, there has been placed a quantity of rip-rap, composed of stones varying in size from 1/3 cubic foot to 11/; cubic yards. around each pier. The object of this rip-rap is to prevent material scour of the river bed adjacent to the piers. Once a year for the next ﬁve or six years, after the high waters have passed, soundings should be made around the piers. If the rip-rap is found to be lower than about twelve feet above the elevation of the bottom of pier base for the Columbia River piers, or six feet above the bottom of pier base in the sloughs, some additional rip-rap of the same kind should be deposited. The elevations of bottoms of pier bases is shown on the drawings. In this connection, we desire to call to your attention that only a small amount of rip-rap has been placed at piers 11, 12 and 13, owing to the sand bar, whose top is above the top of these pier bases. In case the river channel should shift and this sand bar disappear, it will be necessary to place considerable rip-rap around these piers.