|Mobile High Capacity Tower|
|This Tower is a modified
Tri-Ex AB-1309 115' Deployable Mast. Originally built for the Military as
part of a multi-site tactical battlefield communications system, the
designed to survive wind speeds of up to 90mph with proper anchoring.
|Our modifications include a nice grey paintjob to match our other
facilities, a few electrical modifications, and an improved erection stabilization
system which includes rigid outriggers to make
it easier and safer to erect in moderate wind, and useable without guying
at 50-60'. Those outriggers are shown in the bottom photo below.
A second AB-1309 is undergoing overhaul and refit to be equipped identically.
These towers incorporate three remotely controllable azimuth/elevation microwave antenna mounts capable of supporting 4' dishes at rated wind load which allow microwave paths to be zeroed in after a tower is erected. Each microwave antenna mount can swing through 120° of azimuth, allowing the tower to be at the center of a multi-site system.
Radio communications antennas attach to a telescoping "stinger" pipe which comes out of the top of the tower head to place them above the microwave antennas, as well as sectored booms which support additional antennas.
Above about 50-60', these towers require increasingly more comprehensive guying, culminating in a required guy radius equal to the tower height. In other words, at full height of 115', a clear 230' diameter area is required for proper guying and rated wind survivability.
If a tower is to be deployed in an area where ground anchors cannot be driven, such as a parking lot, the customer is required to provide at least three (3) sections of "Jersey Curb" lane barricades to use for anchor weights. A customer-supplied anchor weight must weigh at least 2500lbs, and more is better. The tower cannot be erected until these weights are in place.
Other heavy objects, such as abandoned vehicles, can also be used.
These towers are intended to be used in conjunction with our deployable shelters containing radio and microwave network equipment or as the central point of a distributed system compound in conjunction with our Communications Trailer and Generator Trailer.
An AB-1309 in use at about 60' at the 2007 DARPA Urban Challenge in Victorville, California as part of an integrated communications and power distribution compound.
The antennas in use in this photo are a DB404 at the top of the stinger, two 900mhz "white sticks" which were used for the vehicle tracking and control system, a UHF corner reflector for a directional repeater channel, and three DB408's harnessed as six DB404's on the horizontal booms. Also shown are two Andrew 4' parabolics for the 5.8ghz microwave paths.
Wind gusts of 70+ mph were experienced during the Urban Challenge deployment, so plenty of guying was employed to make sure the microwave paths were stable.
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