Marine Terminal | Heavy Industry | Construction | Crane Systems | by Matt Gergeni | 01 Jul 2014
It is often said that good things come in small packages. However, when it comes to dredge cranes — size matters — a lot. This simple fact was substantiated recently when Canada-based TDC Cranes Ltd. commenced construction on the first large AC diesel-electric powered dredge crane ever built in North America and what was destined to become the largest dredge crane operating in North America.
This daunting task was made even more challenging by the fact that the build requirements for this project specified:
• That the crane be powerful enough to handle a massive 60-yard clamshell bucket
• That the dredge be powered by an environmentally friendly diesel-electric system that eliminated the traditional hydraulic systems
• That the design achieves the highest levels of environmental design standards
• That the clamshell bucket includes advanced software options, delivering industry-leading safety and performance features
• The crane controls must be simple to operate.
“From very early in the process Magnetek was an essential part of our team for this project,” said Rick Gillespie, president of TDC Cranes Ltd. “We weren’t interested in people that were just selling components. We needed a company with the ability to provide complete systems — solutions that included both drives and the custom software required for a project of this scale.”
Over the last two years, Magnetek Inc., a leading provider of digital power and motion control systems for the crane and hoist industry, worked closely with TDC Cranes to engineer the most technologically advanced — and highest-producing — dredge crane currently operating in North America. The dredge, which was commissioned in late 2013, clocked 3,500 hours of operation by the beginning of April, 2014.
The heart of the massive dredger’s precision crane control system features multiple adjustable frequency drives developed by Magnetek, which eliminates the need for the more traditional hydraulic systems that have the potential to leak, creating environmental risks. In addition, the IMPULSE•G+ and VG+ Series 4 Adjustable Frequency Drives provide industry-leading precision and control and extend the service life of the crane from 20,000 hours to more than 200,000 hours.
As you can imagine, it takes an enormous amount of power to operate the dredge’s massive 60-yard bucket which has the ability fill a 5,000 cubic-yard scow in just over two hours—nearly three times faster than any other dredge crane in North America. Power for the vessel is provided by twin Caterpillar diesel generators which produce an impressive 1,600 eKW of power.
The dredge crane features 200,000 pounds of line pull per hoist with a 250 feet-per-minute rating, and a 75-foot operating radius. In order to meet the demands of today’s precision dredging projects, the crane can be equipped with either a 60-yard bucket for trimming or a 28-yard bucket for heavy digging.