Oregon OSHA has issued revised guidelines for using tethered logging systems (winch-assisted, cable-assisted, traction-assisted, etc.), which enable ground-based timber harvesting machines to operate on slopes of more than 50 percent.
Oregon’s 437-007-0935(1)(b) and (c) require that these machines may be operated used on slopes up to 40 percent only, or 50 percent if the machine was designed for steep slopes; general operation beyond their applicable slope limit is permitted only when specified by the machine manufacturer.
Employers who plan to use tethered logging systems in Oregon must ensure that the harvesting machine to be tethered was specified by its manufacturer for operation on slopes of more than 40 or 50 percent, as required, or else apply for and be granted a research variance before using the harvesting machine above its slope limit with a tethered logging system.
Oregon OSHA’s summary said its decision to grant research variances from 437-007-0935(1)(b) or (c) “is to support the use of new technology that could replace dangerous tree falling and timber transporting operations by workers on the ground with operators in machines with protective cabs meeting the requirements of 437-007-0775.
The summary stated that “approved research variances will also provide a means of collecting relevant safety data until Division 7 (Forest Activities) rules can address these newly introduced technologies.”
The summary also lists what the variance application must specify, including the criteria for replacing the tether line and ensuring that tensions do not exceed 1/3 of breaking strength to maintain a 3:1 safety factor or greater.