Spillard News

But researchers for the Silsoe Institute, working for the Health and Safety Commission, warned that many suspension seats will need upgrading well within the lifetime of the plant.

 The researchers said: “Test on two forklifts showed that a suspension seat could reduce vertical WBV by as much as 50 percent, whereas a simple cushion seat actually amplified it by 20 percent.

 “Maintenance, and particularly the replacement of dampers, is an issue with suspended seats that many machine owners and operators are unaware of.
 “The expected operational life of a suspended seat is approximately 4,000 hours, whereas construction machine are expected to achieve 30 to 40,000 operating hours. This begs the question as to how many times a suspension seat is replaced. The answer is probably not very often.”

  The research confirmed that most common types of vibration to force operators to work under eight hours a day, although many vibrate enough to need a monitoring regime.
But the extensive testing on typical site machines found that some machines, most notably articulated dump trucks, wheeled loaders and site dumpers, and created vibration risk in certain applications.

  Silsoe found high vibrations on site dumpers used over long distances rough roadway. It recommended encouraging drivers “not to be too enthusiastic when driving long distances”.

  Silsoe found one of the highest vibration levels on articulated  dump trucks. It warned that “operators would approach the exposure limit value during a normal working shift and probably exceed it if working conditions were poor”. It stressed that good operating practice and properly maintained haul roads were important.

 The researchers also concluded that cabs on wheeled loaders and face shovels should be fitted with vibration damping to reduce the fore and aft shocks when driving the bucket into stockpiles.