OVERHEAD TRANSMISSION AND DISTRIBUTION

Multi-use "AirStair" Improves Line Crew Productivity Significantly

For more than 50 years, Hydro One (and its predecessor Ontario Hydro) utilized its own fleet of helicopters to maintain and provide access to these corridors for all sorts of work applications. In the early 1960's, the company had two Sikorsky S-58T helicopters which were used to hoist powerline maintainers onto the structures for large maintenance projects. This helped reduce the need for corridor access roads and increased the efficiency of the crews. In the late 1980's, these two helicopters were replaced with a single AS 332 Super Puma which performed the same functions. But, in the mid 1990's, the helicopter was sold.

Realizing a continuing need to be able to maximize staff productivity and access structures efficiently in hard-to-reach locations, one of the veteran pilots, John Bosomworth, conceived a design which could be used on the remaining fleet of helicopters for line maintenance work.

The concept was named 'AirStair' and is attached to a Eurocopter AS 350B2, AStar helicopter.

This multi use design can be utilized as a delivery and pick up device for transporting powerline maintainers as well as some limited work station applications. With a small crew, productivity improvements with the AirStair have proven to be significant. There is no need for ground travel from one structure to the other; climb up the structure, perform the work, then climb down. This eliminates fatigue on line maintainers and the necessity to belt and unbelt numerous times while climbing.

The device was structurally engineered by an aircraft engineering company and has stringent weight limitations and weather conditions must be strictly adhered to. The company has a very strict, in-depth training program for pilots and linemaintainers on use of the AirStair. The training program - which includes detailed documentation of the procedure along with the use of specialty tools which were designed specifically for the 'AirStair' - must be completed by both pilots and line maintainers. This makes everyone's role easier to accomplish, with the highest level of safety.

"In my experience, having worked on transmission poles and towers, I enjoy the 'AirStair' as it eliminates the fatigue from climbing," explained Derrick Brydges, a Hydro One powerline maintainer who worked with Bosomworth in the development of the equipment. "You are delivered right to your work location. Other applications, such as climbing inspections, one only has to climb from the top down."

Late in 2001 there was a need identified to install marking devices on the skywire of a multi-circuit transmission line in Burlington adjacent to Lake Ontario. This line is located in the flight path of the Trumpeter Swan, an endangered species nearing extinction in Ontario. A few of the birds had struck the nearly invisible skywire, and were injured or killed after falling to the beach below. The conventional method of installing these markers would have been very time consuming and extremely costly.

As a result the Helicopter section agreed to perform the task with the 'AirStair'. The bird diverters were successfully installed in a very short timeframe at a much reduced cost.

Since this spring, the 'AirStair' has been utilized on two skywire replacement jobs - a 115 KV on H-Frame double wood pole structures with the circuit alive and, more recently, on a 115 KV double circuit steel tower structures. Both jobs were completed on schedule with positive feedback from both crew and supervisors.

Hydro One continues to look at other applications for the 'AirStair'. ET