Manually handling pad-mount transformers took its toll on line crews from Canadian utilities Hydro One and Hydro Ottawa Ltd. Each time the equipment had to be installed or removed, line workers had to find a way to lift the 900- to 1200-lb transformers. Methods ranged from helicopters to manual lifting.
The transformers were extremely difficult to lift, even with four workers at the helm. Hydro Ottawa transported the transformers, which were destined for a backyard installation, on a small cart without hydraulics. Once at its final location, the field employees had to manually maneuver the transformer off the cart and on to the concrete slab or up on to a hydro pole. The utility's risk for an incident or injury happening with line crews handling that much weight was very high.
To help protect workers in the field, the two utilities, which serve neighboring service areas, researched the latest lifting technology. Once they discovered a possible solution, they invited Miller Technology Inc., also of Canada, to provide a field demonstration of its ML1600 Miller Lifter. The machine took the manual lifting out of the equation, which was a selling point for both utilities, who were looking for a way to protect their workers. The business case for purchasing this new technology was an easy sell within these safety-focused utilities. It was acknowledged that prevention of one lost-time injury would go a long way in returning the capital investment.
Hydro One and Hydro Ottawa Ltd. worked closely with the vendor to develop a product that would meet the line crews' lifting capacity requirements. When Miller began manufacturing the machines, Hydro Ottawa Ltd. needed the largest machine available on the market. Miller Technology designed a machine that could lift 1600 lbs, which was the largest size of backyard transformers at the time.
In one situation, a transformer weighed above 1600 lbs. Rather than overloading the machine, the utility called the vendor, which invented a jib that would increase the machine's lifting capacity on a 100% stable and level ground to lift up to 1850 lbs. The company also invented many other quick-attach jibs, such as one that is 4 inches to 5 inches higher so it can lift the transformer up and out of the transformer enclosures.
Reaching Remote Locations
The compact size of the machine and narrow footprint has also been a benefit for the utilities. Line crews can load the ML1600 machine on to the back of a 3/4-ton truck and transport it to a work site.
Because the machine has rubber tracks rather than traditional wheels, it can be used as an all-terrain vehicle in remote areas. For example, Hydro One's service area features many small lakes with underwater submarine cable, which feeds power to surrounding residents. Some lakes feature 40 to 50 pad-mount transformers and minimal road access.
Before investing in the machine, Hydro One had to often use one of its five helicopters to change out the transformers. Getting access to a helicopter, however, wasn't always an option during the summer, when many of the transformers are subject to lightning strikes. The use of helicopters was also dependent on clear weather, while the Miller Lifter can be used in most conditions.
The field crews also work on many pole-mounted transformers in backyards, and the machine has come in handy in these situations. By using the machine, the utilities lessen the work for the contractors, who no longer have to remove home-owners' fences. The Miller Lifter allows line crews to lift the pad-mount transformers and change out the aging equipment with minimal disruption to homeowners' properties.
During storm-outage situations, the utilities also have relied on the machine to quickly change out a transformer. By using the lifting machine, they can usually get the power on within a few hours.
The machine not only allows line crews to change out a transformer more quickly, but it also enables crews to get the job done with less manpower. In the past, it took four to five workers to change out a pad-mount transformer, and now the utilities do the same job with a two-person crew.
Lifting Heavy Equipment
In addition to transporting pad-mount transformers, line crews can also use the machine to lift overhead transformers into position. Workers can use a capstan and rope-style method to lift the transformer up the pole or rely on a bucket attachment, which can help to transport backfill, equipment and tools from the backyard to the frontyard.
Line crews also can use a pole-handling attachment to transport 45-ft poles from one location to another. In the past, workers would manually load a cart with the poles and then drag the cart to its destination. With the machine, the line crews no longer have to tear down fences, because the machine is narrow enough to fit through most customers' gates.
Training Field Crews
To train the linemen how to run the machine, Hydro Ottawa Ltd. brought the vendor in to do a “train the trainer” program with 10 people. The Safety, Environment and Training group completed a training program, which reviewed the safe operation of the machine and also included a practical section. The company then required all crews to attend a four-hour session. The first two hours were in the classroom, and the latter half of the class took place out in the field. During training, the line workers learned how to take the machine up and down hills, load and unload equipment, and handle poles and other materials.
All field employees for Hydro Ottawa Ltd. have now been trained on how to use the machine. Because the company has five separate work centers, the linemen must book the machine for specific projects. In a few cases, the line crews have cancelled some jobs because the lifter was already in use, which is a sign of the machine's value to the workers.
By investing in the lifting machine, the Canadian utilities have helped to improve ergonomics, protect their workers from injury and maximize their efficiency in the field.
Dave Simpson is a lines supervisor for Hydro One. [email protected]
Dave Stephens is a safety and training field specialist for Hydro Ottawa Ltd. [email protected]