Common use of Working methods Clause in Contracts

Working methods. Soundings are to be done using Automated Hydrographic Survey logging System of any accredited/ IHO approved hydrographic survey software. Digital echo sounder (having accuracy of not less than 0.1 m) shall be used for sounding purpose and Differential Global Positioning System (DGPS) / RTKS DGPS (having not less than sub-metre accuracy) shall be used for position fixing. These surveys shall only be carried out if weather and river conditions, condition of equipment and methods of execution and interpretation are, in the opinion of the Engineer, satisfactory for this purpose. The Engineer's Representative may resolve to check echo soundings by means of other methods to measure water depths, such as sounding poles, bar check or lead lines. The Engineers Representative may also order calibration checks of the equipment as and when considered necessary. The Contractor shall cooperate in this respect and supply any manpower, boats and equipment that may be reasonably required for this verification. The Current velocity at every shoal (i.e. at least 3 locations, Starting / Middle / End of the survey area) at 1 m depth from the surface and 1 m above bed level shall be carried out once during the survey period. The Float Observation at every shoal (i.e. 3 tracks are to be observed, one on both the side and one at middle of the channel of the survey area) shall be carried out once during the survey period. Water and Bottom samples are to be collected at two locations (one at the Downstream and other at Upstream of the shoal area) and get it tested for finding the characteristics of the soil and the water.