GPS becomes the ‘standard’ as projects increase in size

The use of GPS is becoming increasingly common on large-scale construction projects. It comes as no surprise then, that the latest technology was used on The Palm Jumeirah. Zoe Naylor lets us know the exact position of an industry that has its eye on ‘global’ domination.

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By  Zoe Naylor Published  October 29, 2005

|~|93prod200.gif|~|The Palm Jumeirah utilised Trimble’s GPS equipment. The pace of construction and the volume of material worked against using traditional techniques.|~|The widespread availability of global positioning system (GPS) means that anybody can determine a unique location on the surface of the planet or navigate across it, not just those versed in astronomy and geodetic positioning. Sailors, climbers and techno-junkies alike now have access to previously unavailable positioning information. The construction sector is also making good use of the technology; the first GPS employed in Dubai’s construction industry was installed on a Cat14H grader and used on the Autodrome. “GPS equipment is now used in many construction processes, from basic land levelling through to building high-rise tower blocks,” says Andrew Cauldwell, regional sales manager (Construction) for Africa, Middle East and India, at Trimble . “There are very few contractors here today (and certainly none of the major ones) who operate using traditional methods,” he adds. Trimble manufactures positioning equipment, from laser hand tools through to hi-tech GPS system. The company was formed in 1978 by three ex-Hewlett Packard staff in response to the US military’s decision to open up GPS signals to civilians. “We developed the first ever GPS receiver for professional use and have worked on all subsequent developments in GPS since then,” says Cauldwell. Trimble has been operating remotely in the Gulf since the mid-’90s and opened an office in Dubai in 1999. Technological advances have transformed the way in which on-site measuring is carried out. Theodolites are rarely used nowadays because all they do is measure angles, while newer equipment such as a total station can measure both angle and distance. Today’s positioning equipment can also be fitted onto plant machinery such as graders, dozers and excavators to automate the machine to the pre-designed data of a job site. It works by controlling the hydraulic systems automatically through a series of sensors. “You input the data, install the equipment and the machine will do everything itself,” says Cauldwell. “All the driver basically has to do is put his foot on the gas and drive in a straight line.” Cauldwell says that when Trimble first introduced GPS technology to construction products in the region over the last 18 months, people who had never used it before were sceptical about its accuracy, speed and reliability. “As with all new technology, a lot of companies will wait for the innovators to buy and use the new equipment. Once they have tested the water, that’s when you get the rest of the mass market following suit.” Some of first companies in the region to have pioneered the use of GPS are Al Futtaim Carillion and Al Naboodah. GPS offers numerous benefits to contractors: “It can make a business more efficient, it reduces wear time on your machine, cuts diesel costs, improves accuracy and provides a more consistent finish. The overall result is you save on material costs, and that’s where the real cash benefit to the contractor is.” And it looks as if the message is getting though: Cauldwell says that over the last five years the volume of GPS units that Trimble sells in the region has increased 20 or 30 times. “It’s all about GPS technology — some of the construction companies in Dubai now have 10 or 12 systems at a cost of US $35 000 each, which is quite an investment. But the benefits that it gives the contactor are obvious and that’s why they re-invest in more equipment.” The Palm Jumeirah is one example of where Trimble’s GPS equipment was used. A number of factors worked against using conventional surveying techniques on the project: these included the rapid pace of construction, the huge volume of material to place, the likelihood of line-of-sight obstructions and the need to move operations quickly around the site. The Palm’s GPS solution revolved around a Trimble 5700 GPS base station. This was installed at the offices of Al Naboodah Engineering Services (the contractors for the Palm’s civil infrastructure) on the mainland beach. A Trimmark 3 radio modem allowed the base station to transmit GPS correction data to three Trimble 5700 GPS rovers on the Palm. By using a rover fitted out with a TSCe controller and Trimble Survey Controller software, the operators were able to stake out surface details, trenches and road alignments. “The dredging company Van Oord also used our GPS receivers on the Palm to position the initial deposits for the structure of the project so when they were dredging and then pumping the sand, they knew exactly where it should go,” says Cauldwell. Research and development is a big area for Trimble, with the company spending in the region of $70 million per year. One of the latest products it has developed is a GPS receiver with L2C capability. “The latest batch of satellites sent up by the US military has a signal known as L2C which enables the civilian population to use it, and it has even better accuracy,” says Cauldwell. The signals from the satellites are slightly scrambled by the US military so the general populace doesn’t have access to the same clean signal. Manufacturers such as Trimble unscramble this signal to try to get it down to millimetre accuracy. “We are currently the only company that has the capability to read that L2C signal in our equipment. We knew it was coming so we researched it and developed it in association with the US military.” Vertical accuracy is another area Trimble is researching: “As there is no satellite in the middle of the earth, you can’t get the vertical accuracy of GPS better than 2 to 3 cm, and this is exactly what airport runway construction and road construction business needs.” Trimble’s answer is a new construction product with GPS positioning on a machine, which is augmented with a laser control to get the height accuracy down to millimetres. While Dubai’s rampant construction sector is good news for the likes of Trimble, Cauldwell says they are already looking further afield: “The growth we’ve had this year has been tremendous but we’re still only scratching the surface. There are an awful lot of contractors in this part of the world, and the Saudi and Qatari markets in particular are spending a lot of money on infrastructure.” Today’s measuring solutions means contractors and surveyors can work faster and more accurately than before. Global positioning equipment fitted onto plant can enhance productivity, improve workflow and allow contractors to take on more projects — of which there is certainly no shortage in this part of the world.||**||

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