In total control

The view on the screen of the bulldozer.

Machine automation is here, but what productivity increases can be worth the investment in the real world? We visit a site that has switched to automatic mode.

If there is one vision guaranteed to terrify the general public, it would be the image of autonomous, robotic bulldozers grazing over the wreckage of cities once populated by humans. 

Fortunately such a chilling dystopia is a little way off. While ‘total control’ ‘dozers are very much a reality, they only follow the blueprints fed into the computer, rather than making their own decisions on large scale urban planning matters.

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The question is, how do such machines work at all, and what advantage can they offer? Simply put, total control is a system where a site is first ‘staked’ using GPS Rovers. These devices consist of a rod, a receiver and a computer. The rod holds the receiver on top and it has a ‘point’ at the bottom, while the electronics sit in the middle.

There is usually a handheld device, which looks like some kind of industrial PDA, which tells an operator what the whole system is doing.

A base station is set somewhere on site and used as a reference point, and perhaps, marking out a site in this way supercedes the use of posts, string, chains or any other old way of marking the ground.

High Stakes
Once the ‘stakes’ have been set, the data is loaded onto a computer with the surveyor’s original drawings. These are then passed to the computers, via radio, in the heavy machinery. The on-board computers can be fully 3D, or they can display the information in two dimensions, or even just as a string of lights, depending on which system has been ordered.

Machines that can benefit from total control systems include not only ‘dozers and graders, but also excavators and even road compactors.

To put this to the test, we visited a large building site in the desert, some 50km outside Abu Dhabi. The site, named South of Shamka, on completion will comprise of 10,000 new villas, taking up no less than 17 million m2. Currently at the groundworks stage, operations have been split between Tristar Contracting and Bin Nawi Contracting.

It is the latter who we visited. When a project covers this kind of surface area, the exact location of the heavy equipment can be a difficult thing to establish, which is where GPS comes in.

Smaller sites can get away with using regular surveying equipment, such as the now-common five-second Total Station, but with this amount of ground to cover, the contractor decided to try a package from electronics firm Topcon.

Initially, this comprised of a system fitted to two bulldozers, with a base station and a ‘rover’ – another device which clamps to the side of a car for taking readings on the move.

The contractor has just put in an order for a further four systems for bulldozers and some for motor graders, which should be extra suitable for fine grading, as the company has just bought several of the new electro-mechanical Cat 14M machines.