Three months ago, we looked at new machines that help build roads around the world. Now, we take a closer look at some of the space-age tech that helps them from above.
Before a single post can be rammed into the ground, the course must stake out with pegs and twine – or at least it used to be before modern technology took over.
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While contractor’s paper plans, tape measures, spirit levels and a whole bunch of people on the ground were once the norm, now the job can be done faster and more efficiently with surveying gear that makes use of the Global Positioning System of satellites (GPS), combined with laser technology for millimeter accuracy.
Laser-based systems have been around for a while, but when combined with satellite positioning, the accuracy and therefore the amount of labour saved, is vast.
Mick Hales, sales manager, Topcon explained “If any mistakes have been made when setting the points, it will be immediately obvious, saving time and money before any of the machines has been switched on”.
Hales believes that a modern replacement for the theodolite, known as a robotic total station can cut surveying time in half. As well as performing the usual tasks of measuring angles, it is also an electronic distance plotting device and all of the data it captures can be uploaded to a computer.
However, to really make use of this technology, the surveyor needs to be trained for a week or two, so that the points are set in the right place. Mike Shaw, Manager, Prolec explained, “One of the key factors is the surveyor.”
“It takes a competent and trained surveyor to get the best out of the system, but fortunately there are plenty in the region.”
Technology
When it comes to equipping the machines themselves, site managers can take their pick of three basic types of technology.
Entry level systems generally just have a read-out of lights or a dial, while 2D products have a screen plotting the steak points or digger arm, while a 3D-system as the name suggests, use complex trigonometry and algorithms to collate real-time data and then display it like the project’s blueprints.
Mike Shaw explained “3D-machine control differs from 2D because it shows you the position of the construction plant relative to a site plan and tracks it movement relative to this plan in real time.”
“In order to achieve this, an external position system is used to provide information about the plant position. This external position system often takes the form of GPS, but devices such as total stations can be used.”
Like the total station, the guidance systems for machines use a combination of laser and GPS. Though modern technology means they can also make use of other satellites used by Russian and European networks.
Without a GPS system, operators are working with limited visibility, as it is almost impossible to see the tip of the blade from the cab.
Hales explained it like “You’re driving a bulldozer and you have no idea where the blade is.”
“The stake could be difficult to see and you would have to pass it again and again.” Going further, he ventured “If you drove down the highway and you close your eyes for ten seconds, you could be anywhere, but with this system you know where you are, all of the time.”
Automatic
When an aftermarket GPS system is fitted to a bulldozer, an onboard computer reads data from the tips of the ‘dozer blade, to work out the exact position in relation to the ground.
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If the machine has been specified with full automatic control, the operator just has to concentrate on maintaining a steady path as the blade height will adjust itself according to the co-ordinates set into the machine.
The market for these devices has been small in the Middle East, but now the technology has become established in Europe and elsewhere, it is set to grow.
A newcomer to the region is Hexagon, a manufacturer of products based on the Leica-Geosystems core.
Manager Ken West said “We know the market out here is big, so we established our office here (in Dubai) about three months ago.”
Other firms hoping to make in-roads through the Middle East include Topcon, Trimble and Prolec offering a range of devices and solutions for the industry.
Diggers
Excavators can also benefit from the live GPS system. The device measures the angle between the stick and the boom as well as the proximity to the earth.
This not only makes the unit more efficient, but Hales suggests there is a health and safety issue as well.
“There will be no need to have one person in the trench, directing the bucket. Obviously anyone standing in front of an excavator is at risk, so moving people away is clearly better.” Ken West said.
“The Leica DigSmart 3D uses an electronic design file of the site and dual GNSS sensor to accurately guide the operator where to work to achieve the desired design.”
A slope tool, for example automatically adjusts the dig depth information to compensate for whatever slope you are walking on, while a trench tool function simplifies trenching and pipelaying, while ramp tool means you can work anywhere on a site to a desired elevation, without a digital design if needs be.
Motor graders
Graders are relative newcomers to macadamized roads, as they didn’t become popular until the 1960s. Compared to other pieces of road-building machinery, they enjoy a relatively easy life, just scraping the top level of soil to a grade.
As a result, they last longer and it isn’t uncommon to find 30-year old examples changing hands around the Emirates. While any grader can be retro-fitted with GPS technology, Ken West strikes a note of caution.
“The system needs to be ‘tight’ for it to work properly, so the machine and its seals need to have been maintained correctly.”
With a 3D system it is easy to create roads with a camber, to allow for rainwater run-off, but the same technology coupled with automatic blade control can be used to make some altogether more interesting features, according to Mick Hales.
“Golf courses are popular with users of this system as you can just put the co-ordinates in. You can also create the bottom of a lake, for example if a shallow ledge needs to be graded in, and the lake doesn’t even need to be completely dry.”
Similarly, Mike Shaw points out “Using our range, it was possible to do a load of underwater work.”
He added, “Without our system, there would be no Palm Islands, as we made the dredgers pin-point navigation work.”
While the market for the new boxes might be small at the moment, the increased complexity of the region’s projects, as well as the money-saving potential, the mesage remains the same: Reach for the stars.