Fire Apparatus

Trench Rescue Companies Enhance Shoring

Issue 9 and Volume 13.

Airshore pneumatic shoring
Airshore pneumatic shoring is used to secure a trench in a training exercise in Australia. (Hurst Jaws Of Life Photo)
Paratech air cushion
A Paratech air cushion is used fill a void behind a plywood panel while setting protection for a rescue.

The terrorist attacks of 2001 generated a rush to equip firefighters and emergency crews with tools designed for urban search and rescue situations, primarily building and trench collapse.

“With USAR and trench rescue, it was never a thought until after 9/11,” said Nigel Letherby, project coordinator with Paratech, Inc., the rescue tool maker based in Frankfort, Ill. “After 9/11, with everything that happened, train stations in Spain got hit [in 2004], subways in London got hit [in 2005], that’s when they started thinking about it. They only start thinking about it when something happens.”

Federal grant money boosted sales of the specialized shoring systems – most driven by air, some by hydraulics – that are manufactured by Paratech and a handful of other companies. Since then, competition among those companies has led to innovations and improvements in the equipment designed for building collapse and trench rescue.

The National Urban Search and Rescue Response System was established in 1989 by the Federal Emergency Management Agency (FEMA) to integrate local emergency crews into task forces prepared to respond to disasters. The attacks on the World Trade Center and the Pentagon turned the spotlight on USAR teams.

Airshore International was one of the early beneficiaries of increased government funding and the focus on USAR. The company was acquired and became part of the Hurst Jaws of Life product line in 2006.

“Airshore was the first to the [USAR] market,” said Hurst Marketing Director Aaron Guenther. “So like anything, if you’re the first to the market you have an advantage.”

Initially the tools, which are sold individually or in kits that can be customized, were acquired by large fire departments and agencies, but in recent years, he said, mid-size departments have been buying the equipment as well. While sales increases were driven by the terrorist attacks, Guenther cautioned that shoring tools have wider applications.

“It’s not just planes flying into buildings and buildings collapsing,” he said. “A vehicle that speeds out of control and crashes into a convenience store is a building collapse. And it’s also a confined space rescue… So while you think about it in terms of building collapse, it’s actually much more frequent than you would think.”

Frequency Of Accidents

The frequency of trench accidents would likely surprise many people as well.

In a 2002 paper, Purdue University researchers reported an analysis by the National Institute for Occupational Safety and Health (NIOSH) of worker’s compensation claims found there are approximately 1,000 work-related injuries annually due to excavation cave-ins. Of those, about 140 result in permanent disability and 75 in death.

Steve Schulz, the national sales manager for Speed Shore Corporation, which makes hydraulic shoring, said excavation fatalities so far this year are averaging one per week.

The reason for the consistently high number of accidents and deaths, according to Schulz and Letherby, is simple – non-compliance with federal Occupational Safety and Health Administration (OSHA) regulations.

“If contractors do what they are supposed to do, there would not be any accidents,” Letherby said. “The thing is they get paid bonuses for speed for doing a job when they are laying pipe. It takes time to place the trench shields and time and effort to move them.”

Schulz said aluminum hydraulic struts for shoring were invented and patented about 50 years ago by Speed Shore. The vast majority of Speed Shore’s tools are sold to the construction market, but he said his company’s sales to the fire and rescue market increased after 9/11.

While some large metropolitan fire departments use Speed Shore equipment, the majority of shoring struts sold for rescue are powered by air. Paratech and Airshore sell only pneumatic struts, while Holmatro offers hydraulic, pneumatic and mechanical struts.

Schulz said Speed Shore’s hydraulic shoring is designed for trench rescue and should not be used for building collapse or vertical work. For trench rescue, he said, “You just get a lot more strength out of a hydraulic piece than you do out of a pneumatic piece.”

He said the advantage of a pneumatic shoring is its versatility. “You can use it as a trench rescue piece. You can use it as a vertical piece, an extraction piece, and they have tons of different attachments,” he said. “But they just don’t do as good a job in trench rescue.”

All company representatives who were interviewed praised their competitors on the quality of their products and stressed that the choice of what brand to buy is a matter of personal preference.

The newest and smallest shoring company, Prospan Manufacturing of Rosemont, Ill., makes pneumatic struts that owner and President Jim Sullivan said he developed to improve what was already on the market.

Product Innovations

One of Sullivan’s patented design innovations is what he calls an anti-projectile system, a way to keep the air-driven piston from leaving the barrel of the shoring in a trench rescue situation. Paratech is responding by developing a system of its own that could be on the market as soon as the end of the year, according to Letherby.

A trench setting is the only place where shoring – also called struts or crossbraces – are put under pressure.

“Shoring’s job is to take away the earth’s ability to move,” Sullivan explained. “If the shoring is applied directly to the trench wall at the install pressures we tell them, we take away the earth’s ability to get a head start… If earth has an opportunity to move, there’s no shoring made that’s strong enough to withstand it. We’ve seen six-by-sixes snap like matchsticks.”

The principle behind shoring protective systems is soil compaction. When a pneumatic strut is put into position between the walls of a trench, the act of applying air pressure is called shooting the strut. “It almost acts as a shotgun blast,” Sullivan said. “It’s very focused at the point of contact with the trench wall, but it rapidly fans out these pressures and compacts the soil, and they call that the arch effect. As long as a worker is between two columns of shoring the earth cannot cave in.”

Sullivan is a career firefighter in Rosemont who has taught trench rescue at Arlington Heights Fire Academy and conducted excavation training for insurance companies.

He has a different perspective on trench accidents than some. “A lot of times you’ll see a trench box sitting off to the side of the road and the public thinks this is nothing but a bad attitude,” he said. “They didn’t want to put the protective system in. Well, in some instances that’s certainly the case, but in most instances it isn’t.”

In many cases, he said, construction and public works employees reach impediments, such as utility lines running perpendicular to the direction of the trench, that do not allow them to use the big metal boxes.

Tabulated Data

Sullivan and a partner created a company in the early 1990s to sell Airshore products for rescue applications at a time when the company, based in British Columbia, was focused on the construction market. He said became Airshore’s top dealer before he started Prospan in 2001 “because I felt the product needed to be improved.”

One of his improvements involves the tabulated data that shoring manufacturers issue to instruct users how and when to use their products, depending on soil and trench conditions. Traditionally fire departments and rescuers have been taught to place a special type of plywood between trench walls and the metal plates or boards that receive the struts.

Arch Effect

But Sullivan said the arch effect allows struts to be used in many conditions without plywood by placing metal plates, called wale plates, directly on the earth trench walls. He said Prospan’s tabulated data provides for his shoring to be used that way with his company’s aluminum wale plates – a practice that provides protection for construction and public works employees, as well as rescuers, who find impediments in trenches.

“Engineers told me it’s not the plywood that holds back the trench walls, it’s the shoring and the install pressure that creates the arch effect,” he said.

Prospan equipment is being sold in a dozen countries, according to Sullivan. His company has never advertised its products, relying instead on its Web site for exposure, although he said he is considering advertising within the next year. “Everybody tells us we’ve got a great product,” he said, “and the problem is nobody knows we exist.”

Shoring manufacturers have different systems for locking their struts once they are in position and under pressure. Paratech’s Letherby encourages anyone looking to purchase building collapse or trench rescue equipment to try out as many brands as possible to determine which system they prefer.

Manufacturers are frequently invited to take their equipment to specialized training events, which he said are held almost weekly throughout the country from April through October. “We like to have the competitors there because you put the products in the end users’ hands,” he said. “Our equipment is easier to use. The firefighters like it because they don’t have to go in the trench with ours.”

Paratech’s struts can be lowered into a trench and locked in place remotely, he said, while the Airshore and Prospan struts require someone get in the trench at least partially to secure the shoring.

“A trench collapse is a very dangerous situation, so the firefighters don’t really want to go in there if they don’t have to,” Letherby said. “We can place ours in and remote turn the collar with using Velcro or using rope or using webbing or if we use our lockstroke we can just put them in and they will lock automatically. So they can actually shore up the whole trench from outside and then go in.”

Shoring equipment can be quite costly, depending on the amount and the manufacturer. And the specialized certification training required to use the tools adds to the cost and is an impediment for many departments, particularly small ones.

Multi-Purpose Equipment

Paratech’s products are the most expensive. “We don’t make specialized equipment,” Letherby said. “We don’t make a lighter and a cheaper tool so you can support a car. You use the same equipment that we use in collapse and trench to support a car.”

A number of companies make specialized struts for vehicle accident stabilization, and he said some of those are being traded in for Paratech struts, which are multi-purpose.

Paratech’s prices range from $3,000 for two struts with four extensions to $200,000 for its most expensive kit outfitted in a trailer with a generator.

Customized Kits

Customized Airshore kits can get up into the same price range, according to Guenther, but basic kits are quite a bit less. An advanced Airshore trench kit is about $30,000, he said, while a building collapse kit is about $33,000 and a USAR kit, which is about 2,200 pounds of equipment, is almost $53,000. The company offers a basic vehicle stabilization kit at about $3,000 and also sells specialized vehicle stabilization struts at $1,900 for a set of two.

Most departments, he said, start out with a kit and add components to that year after year. “You might have a large vehicle stabilization kit or a trench kit with some additional attachments that would serve both purposes,” Guenther said. “It’s really not too expensive for even a small department to have those very specialized tools… Usually if they are buying one big kit or a trailer it’s because they have a grant.”

Among the rescue equipment offered by both Paratech and Airshore are air bags for filling voids in trench collapse situations, as well as for lifting in other cases.

Both companies anticipate a growing international market for their tools in Europe and in developing countries.

Guenther said Hurst expects to share its Airshore technology with a sister company in China, and Letherby said Paratech is already doing business in China.

After a major earthquake hit China’s Sichuan Province in May that killed thousands of people and destroyed thousands of buildings, authorities in Singapore, who use Paratech equipment, sent a team of rescuers to the devastated area.

“They took their cache of equipment and donated it, left it there [in Sichuan] as a gesture of good will,” Letherby said, ” and then Singapore ordered more equipment from us.”

Since then, he said, Paratech received hundreds of orders from China for forceable entry tools. “In the last couple of weeks I think we sent in the region of 1,500 to 2,000 tools over there,” he said. “It’s just been unbelievable.”

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