56 Foot Tilt and Crank-up Ladder Tower BACK
This guyed ladder tower was designed to support my light weight tri-band beam and a stacked 6 meter yagi. At this time, photos show only a 5 element 6 meter yagi on top, at 60 ft.
This information is intended to show how I did it and any attempt to duplicate any part of this design becomes the liability of others. In other words, text and pictures herein do not provide adequate information to safely construct a tower.
The main structure is composed of three 20 foot sections of aluminum ladder from two Werner D-1340-2 40ft extension ladders. Yes two ladders were required. The leftover top section makes a fine work ladder. The bottom section of the second ladder is reverse slid onto the top section of the first full ladder.
A stiff-leg, anchored to my carport structure, is used to tilt the three telescoped sections to ground level for antenna maintenance. The stiff leg is built from heavy schedule 2" square tubing, welded to 1/4" steel plates, and bolted to the car-port. The stiff-leg bottom is set in concrete along with two short stubs of square tubing forming the tilt pin pivot mechanism.
Two worm gear winches ($29 from Harbor Freight) are used, one tilts and raises the mid section in a sequintial fashion, and the other raises the top section only. The ideas is to taught the lower guys so the the bottom two sections are rigid before beginning to crank the top section. Winches are high reduction, have no dog, and stay where left without creep, very controlable, but they are very slow, 10 minutes per operation, tilt-lift-lift (30 minutes for the complete operation.
During the testing of the first two section, a significant safety issue was noted during tilt down operation. At about 45 degrees tilt, the weight of the top section decreased to a point where the top section will extend uncontrollabley and both sections will fall flat to the ground. To prevent this from happening a stop black must be installed when the tilt down begins. This block is placed as show in the pictures and as marked on the ladder section. Cautionary marking and a weather protected written procedute has been placed on the tower anti climb panel.
Cable and pulleys also came from Harbor Freight. The 25ft OEM cable on the winch used to control the sequential tilt and lift was too short and had to be changed out with a 50ft cable. As seen in the photos, the threading of cables and placement of pulleys is quite intricate to facilitate the operation. Over extension is prevented by pully placement however ladders overlap is manually kept at 4 feet by visial observation.... each step is exactly one foot.
Guys are of 5/16 Dakron rope from Thewireman.com and stainess thimbles from Harbor Freight. All nuts and bolts are stainless from Lowes and Home Depot. All metal for shelfs and brackets is scrap aluminum from my junk pile, many pieces were cut from 1/4" aluminum plate. The rest of the story is told in the pictures.
BACK to W5YAR HOME