The Theodolite Live Long And Prosper

I remember my first experience of surveying and in particular the precious Wild theodolite. It was about 1975 and I was working for the electricity company as a junior cartographic draughtsman.

One of my tasks was to go out and help survey the path of proposed overhead electricity cables. This of course usually meant going out to the middle of nowhere in all sorts of weather to map out the proposed line of the cables, pylon bases and any significant height contour variations in between using the trusty Wild theodolite.

I don't remember the exact model we used but after a bit of research for Wild, I think it was somewhere between the 1955 vintage T2 and the 1975 T3.

We were lucky insomuch that the land was, on the whole fairly flat, but we still had a fair number of lakes, rivers, woods and mounds to negotiate through. Armed with the trusted Wild theodolite, tripod, staff, pegs and tape together with the all important note book. We would agree a plan of attack and then daisy chain our way across the landscape. Always staying in visual (eye to eye) contact was essential as this was pre mobile phones and at that time budgets were so tight that we could not afford a walkie-talkie.

This was a real nightmare in summer when the crops were full because even though we were using a 4m staff you only needed a small amount of land curvature and you would lose visual contact with the theodolite operator. You then had no idea where you were. So we would then have to triangulate our way round the field.

So there was a lot of hand waving, shouting and walking backwards and forwards that was necessary to get the job done.

This was all pre GPS  so we had to tie every thing in to some well defined landmark or feature. This often meant throwing a line off some distant building or wall.

As a consequence it all took a long time. With constant resetting of the theodolite over the next base line point with a plumb bob and a strong wind. Then taking measurements and reading off the linear scales and trying to write it all down in some meaningful fashion. But it was great fun and as a bonus I managed to spend most of the 1976 UK heat wave working outside.

When I look at the modern day theodolites together with the technology that is available and taken for granted I realise that we have moved forwards a long way. Obviously if I was doing the job now I would replace my Wild theodolite with a Leica Total Station (Wild were merged with the Cambridge Instrument Company in 1990 to form the Leica Geosystems company).

I now would be able to set up easily over my marker, measure distances directly at a press of a button, store these onboard for future download via USB or Bluetooth. I would determine my actual location via GPS. I can even control my Total Station remotely!

And I could do in hours what may have taken me days to do before.

A modern Theodolite (rather than Total Station) still provides significant advantages over it's 1974 predecessor.