Search

Wooden crossarms play a major role in supporting electric distribution lines in North America, but relatively few data exist on their condition as they age. The residual capacity of Douglas-fir crossarms in service in western Oregon for 45 to 60 years was investigated. Arms were sampled for residual preservative retention, the presence of visible decay fungi, and residual flexural properties; these results were then compared with three nondestructive tools. A majority of the arms tested had preservative levels well below those required for new arms, but only one decay fungus was isolated, and only five arms removed and dissected had any evidence of visible internal decay. Moduli of rupture for the arms were generally below the minimum levels required by national standards, but most still retained at least 67 percent of this value. Nondestructive evaluation tools were generally poorly correlated with flexural properties, possibly because of the heavily weathered and checked exterior condition., Crossarms are widely used on electric utility poles in North America to support the wires and create separation between the electrical phases. Although a variety of materials can be used [...]

ABSTRACT The use of wood in civil engineering structures, such as timber bridges, has been increasing in recent years. Unfortunately, our knowledge of their behaviour towards sustainability problems is far [...]

Abstract The effect of copper naphthenate treatment on electrical resistance of Douglas-fir utility poles was compared with similar poles either left untreated or treated with pentachlorophenol (penta). Penta-treated and untreated [...]

When you team up two scrawny Douglas firs . . . "The scrawny, misshapen evergreen was far too ugly to ever be chosen as a Christmas tree. But then it […]