System Overview
Articulated Tug and Barge (ATB) vessels use an intercon system to mechanically connect the tug to the tanker barge.
The system includes counterweights within a vertical guide frame that assist in the operation of the interconnection mechanism and support associated controls including:
Limit switch actuation
Helmet lubrication
Bushing lubrication
Drive system components
These counterweights travel within a confined guide structure located in the intercon machinery space, directly below several crew staterooms.
Problem
During vessel operation the counterweights can impact the guide frame, producing repeated banging or rattling noises. Because the intercon room is located beneath crew accommodations, the noise is often noticeable in nearby staterooms. Crew members attempting to reduce the noise have historically used improvised solutions such as:
-Stuffing rags into the counterweight guides
-Gluing padding or materials into the frame
-Installing temporary noise dampening materials
These methods introduce operational risk. If foreign materials become lodged in the guide frame, they can interfere with counterweight movement and potentially affect limit switch operation or mechanical travel.
Solution
Custom counterweight bumpers were developed to provide controlled impact damping. The bumpers are:
Thin TPU elastomer bands
-Approximately 1 inch tall and 1/8″ thick
Installed at the top and bottom edges of each counterweight
-Designed as an interference fit, allowing them to be installed without adhesives
-The bands include chamfered edges to prevent snagging or interference with the guide structure.
-Once installed, the bumpers absorb contact between the counterweight and the guide frame while allowing the counterweight to move freely.
Benefits
• Eliminates counterweight impact noise
• Prevents crew from inserting foreign materials into the system
• No modification to the intercon mechanism
• No adhesives or permanent installation required
• Maintains full counterweight travel and system function
Following installation, the counterweight system operates quietly and unobtrusively, and the modification is visually unobtrusive within the machinery space.
Design Insight
This modification addresses a human-factor issue common in shipboard systems. When mechanical equipment produces persistent noise near living spaces, crew members will often attempt improvised fixes to improve habitability. These temporary fixes can unintentionally introduce operational risks. By incorporating a simple mechanical damping solution, the design eliminates the noise source while preventing unsafe workarounds.
Engineering Record
This document records a preventative engineering improvement to reduce noise and eliminate the need for improvised counterweight damping in ATB intercon systems. The solution improves crew habitability while maintaining reliable operation of the interconnection system.
Intercon Noise reduction system is available for purchase below