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Dredging Equipment
Published in Jan van ‘t Hoff, Art Nooy van der Kolff, Hydraulic Fill Manual, 2012
Jan van ‘t Hoff, Art Nooy van der Kolff
If the TSHD or barge can get close enough to the reclamation area the slurry could be discharged through a bow- or side-mounted nozzle (‘rainbowing’). This process of placement is relatively inexpensive, but not very accurate and may, in some cases, not be allowed as rainbowing could produce a spray of (salt) water and fine mud over a certain area.
Evaluation of dredging efficiency indices of TSHDs deployed in a navigational channel leading to Haldia Dock Complex
Published in ISH Journal of Hydraulic Engineering, 2022
Bikas Chaudhuri, Ambarish Ghosh, Balkrishna Yadav, Rajesh Prakash Dubey, Partha Samadder, Arijit Ghosh, Aritra Das, Suvrajit Majumder, Suvendu Bhandari, Navdeep Singh, Sibnath Das
The day-to-day basis maintenance dredging schedules to be followed in between two consecutive tides which are framed considering mainly the locations of least navigable depths, available number of dredgers, permissible limit of SSV amounts and distances of the specified dumping grounds from dredging locations. Only conventional dredging has been performed at HAL and EDEN and maximum amount of SSV taken out from UJS by conventional dredging only. However, rainbowing at Track-C of UJS has been carried out in emergency, preferably in ebb and in the absence of strong easterly wind. The vertical angle of the nozzle of the dredgers is about 37°. The horizontal range of the projectile of the slurry varies between 60 m and 80 m depending on the ejection velocity. The annual amount of SSV thrown out by rainbowing is very negligible compared to that of taken out by conventional dredging. The necessity of rainbowing gradually decreases with time due to availability of more navigable depths. Hydrographic Survey performed in each tides to ascertain the effect of dredging that is change in least navigable depths, cubic capacities, scouring areas and volumes, shoaling areas, and volumes. An overall schematization of dredging plan is shown in Figure 3. The dredging performances and its effect are analyzed on monthly basis. Sometimes important findings are observed and accordingly necessary remedies are taken. However, integrating the monthly results throughout a year as well as achievements against targets, recommendations for more economic dredging are described in the Annual Reports.