Dadatwins
Addicted to ArboristSite
Posted this here instead of equipment since I am looking for thought of the folks that use the equipment, if it needs to be moved that's ok.
One of our 2001 hi ranger contacted a 34kv line at the knuckle, power line arched and broke, fell to the ground, the lower boom had smoke coming out of the area near the knuckle. The boom was still operational with the engine running. The operator was able to cradle both the upper and lower boom. As the boom was cradled, the smoke started getting heavier and some oil started running out the bottom of the lower boom. The fire dept had been called upon the line contact and arrived in time to extinguish what appeared to be a fire inside the lower boom. After the fire was out and the jacks lifted 4 burn marks were on the ground where the pads were. The jacks were on the street pavement directly, no blocks/pads in between. I was not at the scene but talked to operator, he did contact only the one line no other lines involved. It is my thought that a buildup of dirt, sawdust, grease built up inside the lower boom and started to burn when the contact was made. As this debris burned it finally was hot enough to melt through the hydo lines and that oil fed the fire. This dirt buildup allowed the current free path to the ground and created the arch. The upper boom fiberglass insulation fortunatly did not allow the current to travel up to the operator. My thought is that the lower boom insulation was not effective because of the grease and dirt buildup. The boom had passed a dielectric test about 6 months ago. The inside of the boom has never been cleaned since being put into service. The truck is currently at the vendor under investigation to determine cause of accident. Does anyone have any thought about this or ideas about possible cause?
One of our 2001 hi ranger contacted a 34kv line at the knuckle, power line arched and broke, fell to the ground, the lower boom had smoke coming out of the area near the knuckle. The boom was still operational with the engine running. The operator was able to cradle both the upper and lower boom. As the boom was cradled, the smoke started getting heavier and some oil started running out the bottom of the lower boom. The fire dept had been called upon the line contact and arrived in time to extinguish what appeared to be a fire inside the lower boom. After the fire was out and the jacks lifted 4 burn marks were on the ground where the pads were. The jacks were on the street pavement directly, no blocks/pads in between. I was not at the scene but talked to operator, he did contact only the one line no other lines involved. It is my thought that a buildup of dirt, sawdust, grease built up inside the lower boom and started to burn when the contact was made. As this debris burned it finally was hot enough to melt through the hydo lines and that oil fed the fire. This dirt buildup allowed the current free path to the ground and created the arch. The upper boom fiberglass insulation fortunatly did not allow the current to travel up to the operator. My thought is that the lower boom insulation was not effective because of the grease and dirt buildup. The boom had passed a dielectric test about 6 months ago. The inside of the boom has never been cleaned since being put into service. The truck is currently at the vendor under investigation to determine cause of accident. Does anyone have any thought about this or ideas about possible cause?
