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Triangulation Tales


Words and pictures by Gary Haselau.

4x4ing and surveying in Namibia in the early years.

I first became involved with 4×4 vehicles a long time ago when I began working with a Texan called Sam Collins. Sammy had started a company to mine diamonds from the sea, off the west coast of southern Africa. Our area of operations was Namaqualand, and Namibia with its offshore islands, all the way up to the Kunene River.

I was actually the public relations officer for our group of companies, but was asked to take over from the survey manager when he became ill. At that time, what I knew about surveying would have fitted into a thimble. A very small thimble. But it didn’t take long before I was out there swinging a theodolite and tuning tellurometers with the best of them.

The reason for the surveying was simple. Initially, we had a small ship and a couple of large fishing boats prospecting inshore for the gravel containing the diamonds; and, of course, it was essential to record each prospecting location on a map so it could be located again whenever needed. Also, as our mining barges came into operation to actually work the deposits, and recover the diamonds, they, too, needed accurate positioning.

Surveying is all about triangulation, so what was required of us was to have two men set up on two nearby survey beacons, each armed with a new type of machine called a hydrodist. Using a radio beam, the two hydrodists would measure the distance to their opposite number on the ship, and because the baseline between the two land-based beacons was a known factor, it was then a simple matter to work out the ship’s position to an accuracy of one metre. In this way the ship could return to a given spot on the map at a later date, if and when necessary.

The hydrodist was an amazing device – the seagoing version of the tellurometer, which (surprisingly) had been invented in Cape Town. Previously, all survey work had been carried out using a theodolite, but in areas like the west coast, the theodolite – relying on line of sight – couldn’t be used in fog or sandstorms, or (of course) in the dark; whereas the tellurometer could be used under most conditions, with an almost unbelievable accuracy of 14 mm over a distance of 145 km. The marine hydrodist, on the other hand, had an accuracy of only one metre at 50 km – which was, however, more than enough for our purposes.

As it was a desert coast, it was necessary for our two surveyors to be supplied with 4×4 vehicles, and the vehicle of choice at the time was a LWB Series 2 Land Rover. The Series 2, with its 2.25-litre Rover engine, was a very reliable vehicle and served us well in the desert.

For sand travel, we soon learned to replace the ubiquitous lug-style truck tyres that were supplied with the vehicles with a well-rounded road tyre. These we would deflate to 12 lbs pressure (that’s 0.8 bar for you metric fellas) to work in the soft sand. In those days we had tubes in our tyres. And remarkably, in spite of what we’ve since been led to believe by some, we had no problems with punctures; or with tyres coming off the rims at low pressure, as sometimes happens these days with tubeless tyres.

For inflating our tyres, we had what was then called an engine pump. This was a small cylindrical pump with a long hose and a pressure gauge attached. To use it, you had to remove a sparkplug from your engine and screw in the pump, and – with the engine idling – it would inflate the tyres; simple and effective, but oh, so slow.