Grab Bucket Unloaders / Clamshell Unloaders

Grab Bucket Unloaders / Clamshell Unloaders are designed to unload barges and ships containing bulk materials such as coal, iron ore, limestone, bauxite, woodchips, fertilizer, sugar, sulfur, phosphate as well as others.  Richmond Engineering Works can inspect and upgrade your grab / clamshell unloader so that you are maximizing your machine investment.  We can design, engineer, and install structural, mechanical and electrical upgrades to meet the most demanding unloading requirements using the latest technology.  We consider all factors, constraints of the site, water level fluctuation, size and design of vessels to be unloaded, material being unloaded, etc., to provide the most economical and dependable upgrades for your requirements.


Upgrades and Features may include:


  • Replace obsolete DC Drives and wound rotor motors with state­-of­-the­-art Digital Drives and re-manufactured Mill Motors.
  • Upgrade to a PLC-Based Control System for improved system reliability and increased diagnostics capability for the operators.
  • A new Control Cab will give the operator better visibility, modern controls, and more room for safer operation.
  • A new Operator Chair will help to save cab room by incorporating new, smaller controls into the chair. The ergonomically designed chair along with new joystick controls will help to reduce operator fatigue, assuring safer operation.
  • A new HMI/MMI will give the operator the ability to see virtually all machine functions from a single location. This will aid in operations, maintenance, and overall safety. A new Electric House, located on the shore, will contain the new PLC, DC drives, isolation transformers and MMI station. By locating the electric house on­shore, the outage length and the installation costs will be drastically reduced. The old equipment will be abandoned in place eliminating the costly price of removal.
  • New Vector Drives and Motors along with gearboxes on the barge haul system can help to increase machine throughput and help with smoother machine operation. The barge haul controls can be incorporated into the machine PLC.
  • Where it is not practical or financially feasible to replace the M­G set, a new Field Control Regulator can be used to replace the obsolete field controls such as an outdated "Amplidyne" controller.
  • Reduce wiring maintenance issues by upgrading with a state­-of­-the-art DeviceNet platform. With the installation of remote I/O and use of DeviceNet Communication, multiple runs of wire are reduced to a single communication cable.


Clamshell Electrical House

Grab Unloader Control House