Page 54 - Ranger Demo

Into the field
In October 1976 we moved into the field and up to Kaolack in Senegal where a 12th Parallel control point sat on the top of a water tower. The area had some trees of a similar height to our towers, and it was a real challenge to build towers of the right height and in the right places to provide clear sightlines. The recce involved identifying tall trees from the old air photos and climbing some of them, all the time keeping our eyes open for the attendant dangers of snakes in the long grass.
It didn’t take long for the tower team to become proficient. The tower legs were embedded in three holes about 3 to 5ft deep. Anchor posts with a series of holes for leg height adjustment were levelled before attaching the legs of the first section.
Before backfilling the holes, the second section provided an opportunity to move the tower legs to adjust the position of the tower base. Leaving the holes open overnight was not popular as they attracted scorpions!
Figure 3 Tower foundation adjustment
Each main tower section leg was 13ft 81⁄2ins long and could be handled by one man during construction. Half inch bolts secured the metal legs and braces and treated as if gold dust for many could become lost in the disassembly or become spoiled with grit. The penultimate section in the inner tower being placed on the ground at the start of the build.
Once we reached the third section, a pulley was used to raise the legs up the tower. It was then a question of good teamwork to construct the remaining sections on our way to the stars! Triangular wooden platforms allowed the worker to sit or stand in the corners and moved up as the build progressed.
Health & Safety?
Sometimes it was handy to have some brute strength when bolt holes did not quite line up. Hard hats and tethers were used but were often ‘forgotten’ by the workers as they became nimble and confident at height. Not strictly enforce were health and safety regulations. Although we followed most of the safety guidelines – such as they were in the 1970’s – our tower team regarded the whole job as a macho exercise! One of our surveyors was a very devout Muslim, and he even insisted on climbing the towers in his voluminous white robes.
The trickiest part of the completion was raising the instrument welded section for the inner tower. An unwieldy piece of metal!
There was always a great satisfaction to see the towers completed, particularly in open areas where a 90 ft tower was a prominent landmark. At night, in the still air with the birds roosting, and quiet, standing at the top was like flying on a magic carpet.
Figure 4 The legs are hauled into position
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