Mobile ship unloaders — superior technology for efficient port operations

Productive port and terminal operations are critical to growing and maintaining profitable logistics contracts. CDM Systems’ mechanical unloaders are extremely efficient unloading systems, due to the continuous column of product flow using the proven en-masse conveying principle and the company’s exclusive drop-forged chain. A CDM mobile leg unloader is not susceptible to horizontal or lateral misalignment as bucket style units are, and will operate at angles from horizontal through vertical. In addition, a CDM unloader also provides;


  • vessel shifting is minimized when compared to fixed tower stationary units;  
  • mobile legs in eight standard sizes with capacities from 150–700tph (metric tonnes per hour) peak digging;  
  • multiple units working one vessel provide a more even draw-down of the vessel, which translates into better hourly unloading averages than larger single stationary units;  
  • the unloading legs are completely mobile and can be moved to different locations either on board the vesselor by truck;  
  • designed to be handled by auxiliary shore cranes or the ship’s gear. In many cases, several units can be applied to the customer’s operation and will not exceed the initial investment of one single larger stationary tower unit.


En-masse conveying: efficient material movement technology 

En-masse conveyors are an extremely efficient form of high volume material handling. This is why CDM Systems uses the en-masse principle in both its conveyors and marine leg unloaders. Where other technologies have failure points due to misalignment, carry- over, and other material transfer challenges, the en- masse technology is reliable, efficient, and requires little maintenance.

In horizontal applications the en-masse chain conveyor can handle up to 90% of the cross sectional area, resulting in a smaller piece of equipment to handle the same or greater capacities over other conveying technology. These chain conveyors also provide very efficient horsepower consumption keeping operating costs low. The en-masse conveyor is often known as the en-masse chain or drag conveyor, although very different in principle from a standard drag conveyor.

CDM Systems offers a wide range of horizontal, inclined, vertical, or combinations of both in its totally enclosed conveying systems.

Other notable features and application benefits include; v single and dual pit truck receiving; 

  • inline shallow pit hopper rail car receiving conveyor — allows for the positioning of the entire rail car once;  
  • bin/silo distribution conveyors — can be equipped with multiple intermediate gates that provide a positive mechanical sealed separation between the customer’s bins/silos;  
  • several inlet designs can be incorporated on CDM’s bin/silo draw-off conveyors;  
  • CDM provides its standard top flanged inlets for transfer areas where the product is metered and fed into the conveyor;  
  • capacities in excess of 800tph (capacities of over 1,000tph are available);  
  • CDM’s conveyors are designed to operate on a 24/7 350 day/year schedule, while producing durability, dependability, and reduced maintenance costs; and  
  • optional self-metering style inlets that prevent flooding of the en-masse conveyor.

CDM Systems’ material handling experience allows it to provide its customers with multiple style conveyors that include its normal single strand units, double strand, twins, or multiple strands for extreme widths. These conveyors have the ability to convey on the conventional bottom, top, or combination of both simultaneously.