Dozer Domination

Intro

Intro

Using a dozer to get to finish grade has been common practice in Europe for many years, largely due to the high price of graders and the extra costs to hire them out for a job.

In Australia, we tend to place machines into their given roles - dozers for bulk work, graders for final trim. And of course, in many applications such as highway construction a grader is absolutely essential to get within the extremely tight tolerances required.

But for jobs with 20mm - 30mm tolerances such as batter slopes, sports fields, commercial pads, house pads and so on, dozers are fully capable of completing the job and getting to finish grade with the use of 3D machine control technology.

The new, high powered sensors in systems such as Topcon's 3D-MC² are able to transform the dozer's blade so that it can be used like a grader, with 6-way automated measurements over roll and pitch, plus detection of movement in 9 different directions to provide a faster reaction time on the blade.

The use of dual GPS antennas also helps to achieve higher accuracies, with double the signal strength available to the machine control system for more consistent positioning.

Ahead of schedule, under budget (1)

Ahead of schedule, under budget

Contractors are increasingly realising the benefits of using a dozer for finish grading as it enables them to complete jobs ahead of schedule and under budget, using fewer machines. Plus, for smaller contractors who specialise in some of the applications listed above, they can save themselves the investment of a grader altogether.

Ahead of schedule, under budget (2)

Ahead of schedule, under budget

Horsburgh Earthmoving is one such company based in Bendigo, Victoria and specialising in bulk earthworks, subdivisions and wetlands, owner Travis Horsburgh has found that he no longer needs a grader to complete jobs and instead goes from start to finish using a Komatsu D51 fitted with Topcon 3D-MC².

"The quality of the finish with the Topcon 3D-MC² system is incredible," Travis said.

"It really is grader finish, in that where we would have used graders in the past to finish off a job, we are now finding we can finish off with the dozer and get the same results."

In specialised applications such as golf courses, Vince Flemming from Flemming Golf in NSW says their dozer is an overachiever now that it's fitted with Topcon 3D-MC².

"We use our dozers for all the bulk work as well as levelling the fairways and tees - because of the GPS we always deliver under the tolerance levels required in our contract."

Vince said that in the golf industry they are not always provided with digital plans, although it is always their preference, as by entering the design into the machine they require fewer specialist operators to complete the job.

"Our employees are all specialists, but having these systems on the machines makes their work so much easier and more efficient and it takes fewer people to get the work done."

"We always prefer to work off a digital design as we know if we upload it to the machine we will get the results. Of course sometimes the designers then change their minds and we have to adjust it, but that's another story!"

Dozers can do it all

Dozers can do it all

The key advantage of adding 3D machine control to a dozer is that it is the most versatile of earthmoving machines. You can use them in most weather conditions, on steep terrain and in a wide range of applications from bulk earthworks right through to finer tolerance work if you have machine control installed.

"On the last subdivision job I was on, we cut the time needed for a grader by boxing out all the roads, through to the topsoiling - pretty much start to finish, the job was done with the dozer," Travis said.

"I was able to go in and box the roads out to subgrade, then push the dirt into piles for the excavator just to load out, so we reduced a lot of time by not having an excavator there to box the roads out."

"From start to finish, we did the whole subdivision except for the drainage with a dozer, including all roads and topsoiling; I estimate we saved five to six weeks compared with conventional methods," he added.

Changing the tide (1)

Changing the tide

Changing the tide (2)

Changing the tide

As with all new technology, the use of dozers in applications commonly reserved for graders will take a time to become common practice in Australia. We have used dozers and graders for their traditional roles for such a long time that it isn't something that springs to mind as even possible, let alone readily available.

Contractors need to see the results first hand before investing in it wholeheartedly and are unlikely to put a 'for sale' sign on their grader until they are confident that the dozer really can perform to a high enough standard with machine control fitted.

In some instances the choice is not even the contractor's to make, as depending on the job the machines may be dictated by the company running the project with contractors given little or no say in the matter. Project managers, engineers and surveyors also need to see the results for themselves in order to realise the benefits it could have if fewer graders were needed on site.

While graders will of course always have their place for fine tolerance work required in many highway, rail and other infrastructure projects, we can expect to see a marked increase in the use of dozers for finish grade work in applications that require accuracies within the 20mm - 30mm range in the coming years as more smaller contracting and earthmoving companies realise the enormous cost and time savings it could deliver for their business.

End Credits

End Credits

 

Article courtesy of Position Partners Machine Control e-News (October 2012).

Dozer Domination

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