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Modern Contractor Solutions January 2012 : Page 51

THIS SECTION SPONSORED BY Using targeted reflectors, the infrared technology of the Toasters efficiently directs heat into the ground with minimal heat loss. Thanks to these advantages, the units appeared to be an ideal solution for the Skyview Ranch job. “We explored several options before finally finding the infrared heaters,” says Marv Dunwald, owner of Dunwald & Fleming, who struggled to identify alternatives to coal and straw. First, he tried glycol boiler systems to heat the ground, but they proved to be extremely inefficient for utility work. “There was so much heat loss that it would take 3 to 4 days just to thaw 1 foot of ground,” he says. Next, Dunwald experimented with trailer-mounted units, which he found to be cumbersome. “A trailer only thaws about 12 feet at a time,” he says. “Plus, there are only about 10 units in all of Calgary, so nobody can get their hands on one.” Upon discovering the Toasters, Dunwald ended his long, frustrating search and purchased 10 units. His plan for the Skyview Ranch job was to line all 10 of them up to thaw 100 feet of ground at a time. After one stretch of ground had thawed, he would move the Toasters ahead to start heating more frozen ground while his crew trenched the first 100 feet. The process would be repeated until 1,000 feet of ground had been thawed and trenched with gas lines installed and the dirt backfilled. The infrared units provided a safe, quiet heat source, allowing Dunwald to place the Toasters against buildings and fences, and let them operate overnight without close supervision. “Glycol boilers would have been too noisy to operate overnight near residential areas,” says Dunwald, “and most other systems use open flames, which would have been a fire hazard on our jobsite.” WWW.OVERBUILTPAVING.COM It took approximately 24 hours for the Toasters to thaw 1 meter (deep enough to install the gas lines). Therefore, every morning when the crew got to the jobsite, they could move the Toasters and the ground would be ready for trenching. “With coal and straw, we would only thaw about 1 foot every 24 hours,” says Dunwald. “The infrared heat worked up to three times faster.” SAFE AND PRODUCTIVE SOLUTION Not only did the infrared heat system increase Dunwald’s productivity, but it also helped his crew work safely next to the existing utility lines. “We had the inside path, so we were constantly crossing our lines with other utilities,” he says. The ground was thawed well enough that Dunwald didn’t have to be too forceful when trenching with his Yanmar mini excavator. “We could have used a shovel to dig,” he says. The gas line installation spanned 10 days, and all buildings were ready to be occupied by the January deadline. Without the infrared heaters, Dunwald isn’t sure what might have happened. His only regret was not having enough units to get the job done even faster. “We could have worked a lot quicker if we had more than 10 Toasters,” he says. “Then again, the same job might have taken us 30 days if we didn’t have any.” With happy clients and an increasing workload, Dunwald is thankful for the infrared technology that allows him to trench during winter months. And the coal-burning ban that once hampered his business has finally provided a silver lining. Now that he offers services that no other contractor in Calgary can match, when it comes to underground utility installations, Dunwald definitely has the hot hand. ■ january 2012 | 47

National Trench Safety

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