In the beginning of the Gold Rush, the miners were limited because they could only work the areas that were accessible to hand tools along the banks of the streams and rivers. Their equipment was limited to gold pans, sluice boxes and rockers. As time progressed and as they became more experienced, they realised that the deeper gavels in the riverbeds were often richer than the surface gravel along the banks. In the early 1900s, several crudely built steam powered dredges were active on some of the northern rivers of California.  The earliest “spoon-dredges” were employed in 1863 and for a time they won a considerable amount of gold with very simple appliances. Five years later the bucket type of dredge was introduced, and this, in various forms, has been used ever since. Important changes however, have been the introduction of steam dredges about 1882 and electric dredges in 1890. 

The original gold dredges were barges sometimes the size of an apartment house. They were developed from harbor dredges used by the corps of engineers for clearing channels into American ports and they used scoops or buckets to rip up vast portions of river bottom. They cost a small fortune and only the largest mining companies could afford them, but for many mining companies, especially in Alaska and on some of the larger rivers of the Pacific Northwest, they were literally worth their weight in gold. The barges often generated obscene profits with some generating hundreds of times their original purchase price over their careers.  The old time dredges usually used a dragline or a conveyor belt digger in shallow water.

Ladder Dredge removing slide material

Dredge Cuceracha Slide 1915

Dredges Cuceracha Slide 1915

Dredge "Corozal"

Dredge "Clapet"

Dipper Dredge "Cascadas"

Suction Dredges

Ladder Dredge

Ladder dredges submerged in Chagres opposite Gorgona

Ladder Dredges at work in Panama Canal

DREDGING CRANES USED ON THE PANAMA CANAL 2009

Click on images to view larger pictures of dredging cranes

Dipper Dredge "Christensen"

Dipper Dredge "Christensen"

                                                                Dipper Dredge "Christensen"

                                                                Dipper Dredge "Christensen"

Dredging Gatun Lake

Dredging Operations and Titan Crane, Gamboa

Dredge "South America"

Dredges dig, scoop, suck, and spew an ocean of silt and sediment. Dredges are the mechanical beasts that fuel the world's economic engine by clearing and deepening ports for mega-container ships. The roots of dredging go back as far as the Egyptians, who used their hands to open channels on the Nile to keep crops watered. The Romans, who used harbor dredging to keep a tight fist on Europe, pioneered the "spoon and bag" dredge to speed up the process. The Dutch at an early period cleared their canals of silt with a pole to which was attached a bag held open by a steel ring. The apparatus, operated from the side of a stationary barge, was dragged along the bottom and then emptied into the barge. 

Steam power brought about the first large-scale dredges and helped create the Panama Canal. Due to the porous and silted nature of the ground around the Panama Canal, landslides, mudslides, subsidence and silting both above and below the water are common and require constant dredging of the canal bottom and the hills surrounding the cuts.

In April of 2008 in one of the world's largest dredging deals, the Panama Canal Authority awarded a contract to widen the world-famous waterway, with the winning company, Belgium-based Dredging International, set to earn $177.5 million to remove over 50 million cubic yards of sediment.  The project, awarded by the Panama Canal Authority, is part of a larger $5.25 billion expansion of the canal.