The project proposed to undertake load restraint testing to ascertain the engineering qualities of Ultra-High Molecular Weight Polyethylene (UHMWPE e.g. Dyneema®) rope as an effective mean of load restraint for industry and to continue to collect data to build on previous load restraint testing. The overall intent of the load restraint testing was to refine existing load restraint methods to improve feasibility of compliant systems.
What was tested?
Two days of in field testing in Tasmania to understand the following:
Determine the static friction of four types of Tasmanian timber: E.Nitens Pulpwood, Native pulp, Native Peeler and E.Nitens Peeler. These were divided into two separate test lengths: the first at 6m and the second at 12m.
Assess the difference in friction between 6m and 12m log lengths.
Assess the change in log behaviour between restrained and unrestrained.
Evaluate Dyneema as a restraint system.
Further evaluate Belly Chains in testing.
Further evaluate Webbing straps as a restraint system.
The testing of log friction and various load restraint systems in Tasmania showed high values of friction for each of the log species tested, relative to other friction test performed on various log types in other regions. A log that speared during transit indicates that lower friction native Peeler logs may exist.
All bar two restrained tests met the 0.8g requirements. A manual winch webbing in combination with a belly chain achieved the highest tilt angle of 55° (at 1.14G), easily surpassing the 0.8g requirements. However, it proved to be inconsistent in both its applied tension.
Dyneema achieved the highest tension and with the use of air winches achieved the most consistency. The belly chain commonly used in the industry also worked very well. This was especially true in combination with webbing straps.
Finally, Grip plates were seen to be very effective at holding the bottom layer of the logs.