GPS surveying sticks safely into the ground
01 March 2021
‘Quickly’ surveying the location of a cable bed can be very dangerous. But no one really seemed to have been aware of this! Strukton Rail conceived and designed a safe surveying stick. Let’s share this important safety information.
As anyone even remotely involved in work on roads and railways knows, there are underground cables and pipelines located just about anywhere. When they are relocated or replaced it may be necessary to prepare revised cable drawings, so that everyone knows what is located where. Strukton Rail has been using a GPS surveying stick for this purpose for years: a carbon fibre stick, with a removable flat base at the bottom and a GPS device on top. It is not by accident that the stick is made of carbon fibre because that material has the right stiffness. A trench is dug, exposing the cables. A surveyor positions the stick on the line, after which the GPS device – click, beep – measures the exact location and transmits the data to a map.
That sounds very handy, and it is. But it also entails high risk, says Roland Stoekenbroek, Engineer/Trainer at Strukton Rail’s Cable division. “The stick contains carbon, which is an excellent conductor. Suppose that the cable is damaged and the insulation is gone. In that case it is possible for a user to place the carbon GPS stick on an ‘exposed’ cable. This means he/she could get an electric shock. This can be life-threatening.”
High time for a solution. Together with his colleagues, Roland designed a plastic sleeve that can be screwed to the bottom of the stick instead of the original base. The sleeve is ribbed and covers the lower part of the stick, and protrudes somewhat. As a result the carbon fibre can never come into contact with a cable. “My aim was to keep the length and weight of the insulated stick the same as the original stick. After all, it still had to be easy to work with.” And it still is. All Strukton GPS sticks have since been equipped with the sleeve.
“Colleagues like the thought that the stick no longer is conductive.”
Protecting our skilled workers
Oddly enough no one seemed to realise before that the sticks were not all that safe. This only dawned on Roland one day when he went fishing. “The fishing rods have a sticker that says: never cast your fishing rod near an overhead high-voltage line. Should you ‘catch’ the line, your fishing rod will electrocute you, because the rod is conductive. That made me think about our surveying sticks.” After some inquiries and investigation it turned out that indeed there was a risk here.
“Roland discovered a potentially dangerous situation and sounded the alarm,” says Tjark de Vries, Managing Director Strukton Rail, “before there were any accidents involving this stick. It could not be better.”
I consider this a perfect example of how working safely is ingrained into our DNA.
Shared with the sector
As soon as the problem and the solution were known, Strukton Rail sounded the alarm at other railway companies in the sector. Tjark: “Of course this is not something we would keep to ourselves. We have to protect our skilled workers in the railways sector and collectively ensure that they can safely do their work. This is not something we need to earn money with.” Roland adds: “railAlert published a Safety Learning Bulletin about the risks of carbon GPS sticks. It’s a good thing that this is now widely known.”