Dredge Efficiency The Technical Facts

Production starts at the suction inlet pipe.  First order is the ability to excavate at a rate equal or  above that the dredge pumps potential.  Secondly, material must be transported hydraulically by one of the following three styles, an on-deck pump, hull pumps or underwater pump.  The underwater pump has quite an advantage to the deck or hull pumps.  Dredging at a depth of 30 feet and at 20 to 25hg of vacuum the lift is negative 13 psi. After 20 hg vacuum the pump can cavitate, therefore this is the technical limit of an above water pump. When going deeper than 30 feet, the pump is losing potential due to its technical limits. We consider 40 feet of dredging depth to be the depth where an underwater pump is necessary due to effective vacuum limits of the above water pump. The underwater dredge pump has positive in let pressure and can produce more density than can be hydraulically transported by the dredge pump. This positive water pressure  increases the deeper you dredge. A pump at 30 feet underwater has 13 psi inlet pressure and doubles the potential of the dredge over a deck or hull pump.  Automation is the key to maintaining the high density that underwater pumps can produce.   This is accomplished with our production control system.  The Dredge Works DWA-7 production system accomplishes this by velocity and density control. The regulator / dilution device is used, but only as a secondary system. A properly engineered underwater dredge can easily achieve the following targets. At 40ft depth a min of 30% increase in production, at 60ft a 50% over jet assist is not uncommon. . After 60′ a jet starts to decline in effectiveness and under water maintains efficiency. From 60′ and deeper, the under-water pump is the only efficient option. A 100 percent or more increase in production is possible as you dredge deeper.  The only true limit is the density that can be hydraulically transported by the dredge pump. At Dredge Works we build modern productive Underwater Pump Dredges only, not dredges of the past. With global warming there is a need for increasing efficiency in all industries including dredging. The cost has narrowed between the build of a hull dredge or underwater pump model. Many times, the build of a underwater pump model is more competitive than in the past.   The payoff is very quick with the increased production of an underwater dredge pump.  In a new dredge build the only instance where a hull dredge or deck pump makes any sense at all, is dredging at a depth of less than 40 ft.


 At Dredge Works our mission is to manufacture the highest producing dredge.  Our dredges are not custom. We have a three pillar concept. #1 Solid core build. #2 A excavation system that can fully feed dredge pump and handle the deposit conditions. #3 Our automation system is the only way to consistently transport the density that of underwater pumps potential.  Our optional systems are tailored to your deposit and achieving the highest efficiency from your formation.  We produce a balanced design with all systems working together to achieve maximum production.  An additional production of 50 tons per hour is an extra 500 tons extra per day and 125,000 tons per year.  This is our goal for our customers and where you will find the true value that we offer.

Dredge Works = Productive, Innovative, Logical