Every year, 650m tonnes of bulk material are moved on the US inland waterways alone. The logistics chain of bulk materials like coal begins with a barge. Transportation by barge is one of the most cost-effective ways to move coal from the point of production to market. With today’s energy costs steadily rising, this method of transportation is increasing in popularity.
Today up to 20% of all coal movement is made by barges. Why? Because it is the least expensive way to transport coal over longer distances. With Indonesia, Australia and Russia being the largest exporters, these regions are constantly looking for new and more efficient ways to transport the coal to their buyers. They need to cut costs down to a minimum, while streamlining operations in order to strive for more operator control and increase dockside safety. This is not an easy task. The vector-opposed barge haul system consists of two opposed winches that work in tandem with a continuous diameter steel cable that includes two master links with a hitch rope for tying to the material barge. The barge can also be secured against drifting away from the river cell or dock face by a continuous barge-breasting cable. This is the fastest and safest way to handle and offload a barge.
The two winches are mounted to the dock-cell tops with high-strength epoxy grout and several anchors. Each winch has a rated capacity and a variable rope speed depending on the application, size of the barge, and weight of the material.
Easy and safe control
The barge haul system can be operated from inside the E-Crane operator’s cab or from a remote location by ground personnel while an empty barge is substituted for a full barge. Local controls are also mounted at each winch.
The push button station inside the E-Crane cab is located for easy, convenient use; and a foot switch provides for hands-free barge hauling while the operator is simultaneously unloading the barges.
The control system uses dual vector drives, commanded by a PLC, to electrically co-ordinate both winches for maximum control over the barges. The operator’s station allows for independent or tandem operation of the winches. In tandem mode, the forward winch pulls rope in while the trailing winch pays rope out under controlled back tension. Winch motor speed is continually monitored by the PLC to eliminate freewheeling or loss of payout control. Acceleration and deceleration ramps with brake delays are programmed into the system to prevent shock loading Of equipment.
The system also includes a NEMA 4 vector electrical control enclosure with all appropriate auxiliary equipment for the barge haul drive control system, transformer, distribution panel and other electrical equipment.
Custom solutions for every application
Each balance crane and auxiliary equipment/systems are custom engineered for the customer’s specific application type, production goals and profit potentials. Thus the barge-haul system specifics may vary from application to application, also depending on peculiarities such as the river current speed, water level fluctuations, convoy sizes, space available for unloading equipment, and any harsh environmental conditions.
If the infrastructure, environmental issues or other circumstances do not favor a permanent installation, the complete material and barge handling package can be mounted onto a floating material handling platform. In this case, experienced naval architects and qualified barge builders are hired to assure compliance with all regulations and to assure a high quality, cost efficient offloading solution. The floating material handling platform is the ideal solution where there is little or no existing infrastructure; when environmental issues prohibit the construction of a permanent infrastructure; or if the flexibility of a floating, moveable system is desired.
Source: International Bulk Journal, April 2013