RIASSUNTO
ABSTRACT:
Indonesia has extensive experience on tin dredging operation, both inland and offshore. As the inland tin ore deposits get scarser and poorer, the dredging operation had been moved in to the offshore tin ore deposits. When those deposits were going deeper and deeper, the size of the dredges were getting bigger, and the digging capability must also reach deeper deposits. Consequently some problems arise, i.e. the digging capability, wind resistancy, center of gravity, load distribution, pontoon shape and size, etc. These problems are pointed out. In the pursuit of environmentally sound and sustainable development, the Indonesian Government has forced through an Act, Law and Government Regulations to the Indonesian State Owned Tin Mining Company, namely P.T. Tambang Timah, which operates the dredges to control the dredging placement and techniques, so as to minimize or mitigate the negative impact upon the living environment.
INTRODUCTION
The dredge may have been the first continuous mining equipment invented for underwater excavation of an alluvial deposit. The modern multi-bucket dredge or bucket-line dredge is actually a combination of a floating excavating vessel (pontoon) with a mineral processing and waste disposal facilities. The end product is a concentrate consisting of the valuable minerals and associated heavy minerals which are taken to a treatment plant ashore. Indonesia has dredging operation, It has been started very long experience OD both inland and offshore. since 1948 when the tin mining companies wanted to own more efficient and productive equipment. But in 1958 as the inland tin ore deposits get scarser and poorer, the dredging operation had been moved in to the offshore tin deposits. When the offshore tin ore deposits were going deeper and deeper, the size of the sea dredges was getting bigger and the digging capability must also reach deeper deposits.