Reg Bowders explains the workings of the electronic detonators used with fireline explosives. The detonators have a radio transmitting range of 5 miles in line of sight, making for a much safer method of dropping large trees. Photo courtesy National Park Service.
One of the things most people don’t realize is that after a forest fire passes by or over a roadway, there’s a significant amount of debris and hazardous trees that may have burned or partially burned and left snags that need to be removed for safety. That’s where Reg Bowdler comes in. Reg is the US Forest Service’s regional blaster from the Stanislaus National Forest. His job is to utilize high explosives to clear dangerous and difficult trees and snags that can’t otherwise be safely removed. How does he do it? With a loud bang of course.
“Safety is the main benefit of using fireline explosives,” Bowdler explained. As crews work to re-open Big Oak Flat Road and Tioga Road in Yosemite National Park, expert sawyers evaluate trees for safety along the road and identify hazards that need to be removed. In some cases, trees are too large and have too much fire damage to cut down safely using typical tools such as chainsaws and wedges. “Fireline explosives give them the option not to fell the tree with a saw,” says Bowdler. Instead, a blaster using a radio transmitter can topple a dangerous tree with fireline explosives from up to five miles away.
The explosive, which is manufactured in ninety-foot long tubes an inch and a quarter in diameter, is taped to the side of a tree in a bundle. By packing the explosive properly, an expert blaster can determine the direction in which the tree will fall in order to minimize damage to nearby trees and other resources. According to Bowdler, fireline explosives are generally used to clear line in wilderness areas when crews are short on time or don’t want to leave tree stumps. Because fireline explosives throw debris without leaving a pattern, they leave a more natural appearance along the line. On the Big Meadow Fire, fireline explosives are being used mainly to remove hazard trees.