2007-136 - Laserfiche WebLink

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The CONTRACTOR shall notify the COUNTY in writing one ( 1 ) day in advance of the mobilization of each piece of floating equipment. Mobilization into the work area shall be through the corridor limits shown in the Plans. No anchors shall be deployed outside the work area. All floating equipment shall be self-propelled or directly pushed when landward of the —200 foot NGVD contour line. The CONTRACTOR shall monitor the location of each piece of floating equipment mobilized through the use of horizontal positioning equipment which has an accuracy of at least + 3 feet. Position data shall be recorded every - A copy of the data and plots shall be provided to the COUNTY daily in the Contractor's Daily Quality Control Report (Appendix G). If any floating equipment (barges, pipe strings, dredges, etc), other than self-propelled vessels (tugs, survey boats, crew boats, etc), leaves the project area and is remobilized into the borrow area, these mobilization procedures shall be repeated. 27.2 Demobilization. Demobilization shall be according to the same requirements for mobilization specified in Section 27 . 1 . 28 . EQUIPMENT POSITIONING AND CUT DEPTH MONITORING Accuracy and Precision. The CONTRACTOR shall have equipment on the dredge that continuously measures the vertical and horizontal location of the cutterhead, drag arms, dustpan, or clamshell and is interfaced with the cut depth positioning equipment. The specifications for this equipment, calibration information, and limits of accuracy are to be provided to the COUNTY. The COUNTY will approve or reject use of specific equipment based on accuracy. Horizontal accuracy for dredge positioning shall be within +3 feet. Vertical accuracy for dredge depth positioning shall be within + 1 . 0 foot. This equipment shall provide a permanent record of the equipment' s position referenced to State Plane Coordinates (NAD 83 , Florida East Zone) and NGVD 29 datum. During dredging, reports on the position (x,y) of and bottom elevation (z) of the cutterhead, drag arms, dustpan or clamshell shall be provided. This position shall give both horizontal (in State Plane Coordinates, NAD 83 , Florida East Zone datum) and vertical (depth corrected for tide in feet referenced to NGVD 29 datum) position. The dredge depth (cutterhead, dragheads, or dustpan) shall be corrected for tidal fluctuations by a method pre-approved and acceptable to the ENGINEER. The tide measurements must be acquired and applied to the vertical control equipment on a real-time or hourly basis. At a minimum the report shall give the location at 30 second intervals for cutterhead, hopper, clamshell or dustpan dredges. During unloading of hopper dredges and scows, data shall be collected at the time of the beginning of the unloading and immediately prior to departure to the borrow area. The CONTRACTOR shall also submit an ASCII file and a plot of the horizontal positions of the dredge for each day. The plot shall show the borrow area and dredge area limits, the dredge position, a north arrow and the Florida State Plane grid. The plot shall contain numbered position fixes that correspond to the positions discussed above. The previous day's data shall be provided to the COUNTY daily as part of the Contractor' s Daily Quality Control Report (Appendix G). The location on the dredge of the positioning system antenna and the distance and direction from the positioning system antenna to the TECHNICAL AND ENVIRONMENTAL SPECIFICATIONS � ' . _ 'r TS-26