Dredging Winch Instrumentation Completed for U.S. Army Corp. Settling Pond

Measurement Technology NW (MTNW) & Thern announce successful installation and commissioning of winch monitoring systems at the U.S. Army Corp. drinking water settling pond site, Georgetown Reservoirs in Washington, D.C. Thern & MTNW collaborated with Liquid Waste Technologies (LWT), Archer Western and CH2M Hill to develop and install a winch instrumentation retrofit that monitored tension on 15 separate cables.

The Georgetown Reservoirs site features six, dual-reaved Thern winches and three tensioning winches which support the movements of the LWT Pit Hog™ lagoon dredges. Due to the complex system of pulleys and turning sheaves used to support the movement of the dredges, the U.S. Army Corp had experienced an over-tension event at the initial commissioning of the system, which caused a parting of one of the winch lines.

To prevent another instance of line parting and to ensure the safety of employees and equipment, the U.S. Army Corp enlisted several companies to propose solutions that would automatically shut down the winch system if high line tension conditions were detected. To help monitor the lines in real-time, MTNW provided 15 RL-05 running line tensiometers. These compact running line tensiometers can be easily attached to existing winch installations, allowing the operator to retrofit any winch system to monitor tension, speed and payout of the line.

The goal of the new monitoring and control system was to ensure that the line tensions experienced by the system did not exceed the safe working load of the 3/8-in. cables. For this application, three RLT’s were connected to a single multi-winch LCI-90i unit, concentrating the I/O counts and minimizing equipment costs.

The LCI-90i provided operators a local display of the line tension but also provided alarm outputs, high tension and low tension, which were interlocked to the PLC control system. This prevented the lines from overload and kept enough tension on the lines to keep them from touching the ground. Articulated arms were also provided by MTNW to support the RLT’s in place.

Source: Measurement Technology NW