More and more power lines are nowadays constructed in inaccessible terrain, amongst others, due to the commercial demands on land. Compounding this problem, environmental pressures prevent or prohibit the construction of servitude roads needed during the construction process. This necessitates the power line to be built with helicopter assistance.
Our purpose-designed chutes, capable of delivering up to 1m³ of concrete are used to deliver concrete directly to foundations when it is impossible for the mixers to reach to work site.
The following scenario illustrates typical production speeds
- Helicopter type: AS350B3
- Distance between concrete mixer and foundation:1 km
- Altitude: sea level
- Average day temperature: 22°C.
- Concrete moved: 36 m³ (6 x 6m³ concrete mixers)
- Flight time: 2 hours 25 minutes.
We utilize two types of stringing techniques. In both cases, we lay lead wire directly into purpose designed pulleys, pre installed on the tower structure.
With the suspension frame technique, a remote controlled baking mechanism is used so that the pilot is in total control of the speed of the reel, thereby preventing overruns of the reel. Because the rigs are designed for rapid interchange, little time is lost once a reel comes to its end.
The alternative technique requires us to pull the lead line directly from the reels, which are installed on elevator cradles; complete with a braking system to prevent overruns and is controlled by a ground operator.
To facilitate simplified logistics, our stringing rigs are completely collapsible to enable us to transport the rigs with the helicopter during deployment.
Speeds of up to 250 meters per minute are achieved and pulls of up to 5km have been achieved.
Lattice steel construction
Due to the ability of our pilots to hover with pinpoint accuracy, we have developed techniques to perform aerial assembly of structures on-site when it is not possible to pre-assemble these towers..