Estimating load weights with Huber's Cubic Volume formula: a field trial.

Abstract

Log weights were estimated from the product of Huber's cubic volume formula and green density. Tags showing estimated log weights were attached to logs in the field, and the weights were tallied into a single load weight as logs were assembled for aerial yarding. Accuracy of the estimated load weights was evaluated by comparing the predicted with the actual load weights as measured with scales in a helicopter. A total of 110 loads were evaluated. The load weights were accurate (about 10-percent error), and the method was easily applied under difficult logging conditions. The number of aborts caused by inaccurate estimation of load weights was small (six). Increased efficiency provided by accurate estimates of load weights was often negated during the assembly of loads and in the hooking operation. Greater yarding productivity can be achieved when an accurate log weight estimation technique is combined with efficient load assembly and hooking operations.

Citation

Waddell, Dale R. 1989. Estimating load weights with Huber''s Cubic Volume formula: a field trial. Res. Note. PNW-RN-484. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 12 p