Ascending in the Amazon
Alimak Hek rack-and-pinion elevators provide access to power lines high above the Amazon River, deep in the rainforest.
Home to millions of insects, thousands of exotic animals and the most diverse population of plants on earth, the Amazon rainforest presents one of the most challenging physical environments in the world. So, when energy industry contractor Isolux Corsán needed access to a pair of 295-m-tall towers to carry a 500-kV cable across the Amazon River in Brazil, the company called on Sweden’s rack-and-pinion elevator specialist Alimak Hek.
Each project presents its own challenges, and the Amazon project was no exception. Alimak Hek spokesman Andreas Magnusson described the process of simply reaching the site, located near the Equator and the village of Almeirim:
“You first need to fly with a small plane, and then it’s an hour by speed boat on the river – with snakes, giant turtles, crocodiles, big spiders, parrots and other exotic animals. The Amazon rainforest boasts extreme heat, humidity and heavy rains. The transmission towers are the tallest of their kind in South America. Alimak rack-and-pinion elevators adapt well to extreme conditions, tight spaces and windy conditions, climbing to the very top of the highest structures in the world.”
For comparison, the towers’ height is equivalent to that of the Eiffel Tower. Access to the towers is necessary so maintenance personnel can tighten power-cable stays and change aircraft warning lights located on each tower. In 2013, personnel serviced the stays three times. Each tower elevator has a capacity of 500 kg, or six people. Developed and designed for use in extreme industrial environments, the elevators were manufactured at Alimak Hek’s production facility in Skellefteå, Sweden, a process that took about 12 weeks. An Alimak Hek supervisory team traveled to the Amazon three times to oversee installation before the units were commissioned in March 2013. Brazilian Alimak Hek technicians then traveled to the site once to ensure the units were working properly.
The elevators reach heights of 288.6 m. Their rack-and-pinion systems provide a safety advantage over traditional traction elevators, Alimak Hek points out. “In a power outage, the car uses gravity and a centrifugal brake system to slide back to the nearest landing at a controlled speed,” Magnusson states. “Should the elevator car exceed the rated speed when descending, the car is stopped automatically by the Alimak safety device.” Another advantage, he said, is that the elevators carry their own machinery, and, therefore, do not need an expensive machine room or load-bearing elevator shaft like the wire-rope or hydraulic elevators. And, they are built to last. Although Alimak Hek elevators typically have a 25-year lifespan, some of these elevators are still operating at about 40 years of age. “In tough environments, it is not uncommon that we refurbish elevators that are 20 years old or more and make them as good as new,” Magnusson said. “We have examples of offshore elevators that have been in use for 25 years in Norway’s North Sea.”
A Wealth of Experience
Alimak Hek has done considerable work for the power industry, providing elevators on a variety of large structures, including chimneys, boilers, scrubbers and silos around the world. Its industrial elevators have capacities ranging from 300-2400 kg and come in 30 standard car sizes up to 1.56m X 3 m. Travel speeds reach 1 mps, and maximum lifting height with standard accessories is 250 m. In addition, the company has designed elevators with capacities up to 24 mT and lifting heights up to 645 m. It has designed and built elevators for structures in some of the world’s most challenging climates, including:
- Halley Research Station, Brunt Ice Shelf, Antarctica, one goods elevator, 20 m
- Arab Potash Plant, Dead Sea, Jordan, five elevators, 20-38 m
- Fjardaal Aluminum Smelter, Reydarfjordur, Iceland, one elevator 35 m
- Chimney Stacks, Mt. Isa Mine, Queensland, Australia, two elevators, 270 m
- Yangze River Crossing, Jiangsu Province, China, two elevators, 330 m