SpanGuard™ AL High Temperature Marker
SpanGuard AL power line markers are constructed from aluminum for direct attachment to high corona, high voltage ACSS/ACCR lines and are rated up to 250° C (482° F) and 500 kV. Plastic and fiberglass markers can melt or burn in those conditions. Our markers are routinely installed by helicopter. As with all SpanGuard markers, EHV markers use spiral wire preforms for secure attachment. SpanGuard AL markers are available in 12”, 24”, 30″, and 36” diameters. Available colors are international orange, yellow, and white.
For over 50 years, SpanGuard power line markers have been saving lives and protecting valuable power lines by making them visible to low flying aircraft. Because of their durable construction, easy installation, and “line friendly” performance, SpanGuard power line markers continue to be the choice of utilities around the world.
The FAA advises that 36″ power line markers be used on high transmission lines and hazardous river crossings. Smaller 20″ power line markers are permitted on less extensive power lines or on lines in approaches to airports below 50 feet. Each power line marker should be a solid color—international orange, white, or yellow–and the FAA suggests that alternating colors be used on critical lines to optimize visibility in all seasons. (Orange alone may be difficult to see against fall foliage).
SpanGuard AL power line markers are rated up to 250° C (482° F) and 500 kV on ACSS/ACCR lines, where plastic or fiberglass markers can melt or burn. Made from aluminum, SpanGuard AL power line markers are also lightweight. The 36″ model weighs just 20 pounds. Smaller SpanGuard AL markers are suited to dual and triplex lines where larger markers don’t fit. They can also be used as bird diverters on high voltage lines to protect wildlife, avoid federal fines, and prevent costly damage. SpanGuard AL markers are available in 12”, 24”, 30″, and 36” diameters. Available colors are international orange, yellow, and white.
Spiral Preform Attachment:
SpanGuard AL power line markers are securely attached to the conductor or shield wire with spiral formed armor rods. These spiral preforms extend outward from the marker and actually reinforce and protect the conductor at the point of attachment. They are completely slip-proof. To our knowledge, none have ever come off the line. The preforms are matched at time of order to the specific size, type, and diameter of line. 12″ SpanGuard AL power line markers are attached to the line with special clamps and can be installed over spiral preforms for enhanced line protection.
SpanBrite Nighttime Option:
SpanBrite reflective tape is an option available with all SpanGuard markers, making them more visible at night for helicopters and small planes. Directional landing lights reflect off the tape, making the marker visible up to 2500 feet away at night (750 feet with a small flashlight). SpanBrite is superior to phosphor paints, which are slow to react.
SpanGuard AL Assembly & Installation:
SpanGuard power line markers are easy to install on the ground or from a bucket, and they are ideally suited to installation by helicopter. This makes it possible to install markers on otherwise inaccessible line across rivers or deep canyons, or where it is not feasible to take the line out of service.
Two helicopters can install over 100 SpanGuard markers in a single 8-hour shift, including refueling time. The power line markers can be largely assembled on the ground in a “clamshell” configuration with the spiral preform in place. In the air, the preform is ready to wrap around the line and only the three bolts closest to the installer need to be installed. P&R Tech partners with Haverfield Aviation and other helicopter services to coordinate the ordering and installation of power line markers.
