Can You Ever Have Too Much of A Good Thing?

A 2.196Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

Sometimes a very simple question can generate a very complex answer. Have you ever wondered if you can have too much of a good thing, I believe the answer to that question is fairly simple--yes and no. I would like to take a look at this question as it relates to modern construction site and more specifically as it relates to machine control on the modern site. While I am sure that I will generate a great deal of debate to this answer in regards to accuracy, I think that everyone will agree that there is no debate when it comes to increased profits and improved efficiency. I want to take this opportunity to explore the relationship between accuracy, efficiency and profits. I hope that this article will cause you to reflect on your own needs and challenges because not every company is created equal and there is no magic answer or one size fits all system.

Everyone wants to provide the best finished product possible, but we have to ask ourselves what we are willing to sacrifice--accuracy, efficiency or profits. Ten years ago there was no mainstream access to automatic machine control (just think about how far technology has come in such an incredibly short time), we still had the ability to provide finished sites to within ¼" accuracy but it was not an easy thing to accomplish and required many man hours and extremely talented operators. Just because you had the ability to provide that type of finished product did not mean that you did it on every project or every phase of the project. Let's take a look at a couple of sample projects:

Example #1
50 Acre Commercial Site With 500,00CY of Cut/Fill
After clearing and stripping of the topsoil, traditionally the contractor would have a surveyor come to the site and set grade stakes for rough grading of the site including underground utilities and the building pad. During this phase of construction time and efficiency are much more important than tight accuracy. Cutting slopes, opening trenches for utilities and rough grading for the building pad does not require extremely tight tolerances. Without the use of machine control technology, most contractors will have the grade stakes set a minimum of three times during the course of rough grading and installing the underground utilities. Even with machine control, most contractors only have one or two machines on the jobsite and they dedicate those machines to "fine" grading. One of the top complaints that I hear from customers is that the machine is great and eliminates most of the grade stakes, but without grade stakes on the site, all of the other machines are grading blind without knowing exactly where they are located on the site or what the cut / fill is while they are grading. On this project, there is no reason to provide anything better than 1/10th of foot accuracy and more than likely even that is tighter than what the project requirements are. This is a classic example having too much of a good thing and not enough at the same time. There are one or two machines on this project with machine control which are dedicated to fine grading when the reality of the project does not require any fine grading at this phase of the operation. Without stakes the other machines are relying on information being relayed from the machines with grade control or cut/fill information being supplied by an onsite grade checker with a rover. While it is true that the contractor is providing a better finished product that what was required, they are more than likely doing it at the expense of efficiency and profits. As opposed to having several machines relying on the finish dozer or a grade checker to provide cut/fill information to them, it would be much more efficient to have the mass excavation equipment outfitted with a lower cost, lower accuracy machine control system. Having all of the machines outfitted with a cost effective system which meets the requirements of not only the project but the capability of the machine will increase efficiency and maximize profits. Contractors don't use one type or size of machine to execute a project from start to finish and they should have the ability or opportunity to match their machine control technology to the function and capability of the machine it is on. There is no reason to have the same system on a motor grader which is finishing the building pad to within ¼" and a large excavator working on a 20' cut trying to maintain a slope within a few inches. Both operators of the machines need to see the same project information but they also have very different requirements for the type of work they are doing on the project. A contractor is not going to use a 250hp, fixed blade dozer to finish a building pad within ¼" or build complex slopes within a 10th, so why should they put a machine control system capable of that type of accuracy. The operator of this machine still needs to know the basic information of the project and would be much more efficient if that information were provided to them in real time anywhere they were on the jobsite.

Example #2
3 Mile Road Project with 500,000CY of Cut/Fill
Because of multiple reasons which would make for a good article in itself, most DOT projects require much greater tolerances that private site jobs. In order to achieve these tight specifications, contractors that perform DOT work have evolved to be very specialized or at the very minimum have divisions within their organizations that specialize on DOT work and all of the tight regulations and specifications. Traditionally, and in far too many cases even today, DOT work is done using string lines, hubs and levels to provide a finished product. Automated machine control is just recently being accepted as an approved method of grading by many state and county DOT divisions. Contractors bear part of the responsibility for the slow adoption of machine control on DOT projects. All too often the contractor would get comfortable using his GPS and assumed that because he was getting better than 1/10th on some of his projects that it would be ok on DOT projects as well. It only takes one bad experience with new technology by a DOT to ruin it for everyone. When the inspector comes behind you and finds that while the specifications say that you were supposed to be within ¼" and the reality was that you were only within 1" in some areas, they simply say "go back to string lines and hubs because we know that works". In this case more is better, more accuracy is much better than more machines with less accuracy. It is true that dozers using traditional GPS machine control are faster and easier to use than motor graders using laser augmented GPS or robotic total stations to guide them, but what is also true is that GPS dozers are not nearly as accurate as the other systems available and in the case of DOT's, that accuracy is needed. One motor grader equipped with a laser augmented GPS system or a robotic total station controlled system will perform much more efficiently than multiple dozers with conventional GPS having to be augmented with string line and hubs. More accuracy in this case is much more efficient than more systems and better efficiency means better profits.

The above are simply two examples out of hundreds of possible scenarios, but they do illustrate that there is not a one size fits all product when it comes to machine control and guidance. Contractors have to think about all of the factors involved with their operations--budget for systems, what type of machine fleet you have, what type of work do you specialize in and most important--what type of finished product is the end user expecting and willing to pay for. Yes, you can have too much of a good thing, but one thing you can never have enough of is profit and more systems can enable the contractor to make more profits--they just have to be smart and match the right system to the right machine to the right job.

Mike Nixon is a Product Marketing Manager with the Intelligent Machine Control division of Komatsu America Corp. He has more than 20 years of experience in machine control sales, Trimble GPS, Topcon GPS, surveying and construction management.

A 2.196Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

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