Motor graders are not easy to master. They are among the most sophisticated pieces of construction equipment - and consequently take a longer time for operators to become proficient at. A new operator is faced with an array of controls for eight functions that directly impact how the grader's moldboard or blade is positioned. Add in the operation of the differential lock, all wheel drive, inching clutch, 11 gears, the right engine speed for efficient operation - and the operator has a lot to think about. Even a slight adjustment to any control means that the grade produced by the grader could ruin the job. This, of course, means added cost and delays through rework.
Because of this complexity, trainee operators need much longer with an instructor. Here, communication between student and operator is vital, so not only the basics can be discussed, but also bad practices spotted and corrected before they become habits. While simulators do help with control familiarity (Volvo supplies an interactive DVD with each grader) stationary simulators do not - yet - allow the trainee to experience grader movement and real-time interaction as the terrain changes.
Of course, new motor grader operators can learn the fundamentals of road construction or site preparation etc in a classroom - but there is nothing so good as hands-on training.
One hard to ignore fact about modern motor grader cabs is that they are designed for a single person, seated and with the seat belt fastened - to provide the protection ensured by ROPS/FOPS certification. There simply isn't room for an instructor to be located inside the cab with the trainee. 'Hanging' off the side or standing on the cab step of a moving grader is also forbidden since one slip could quickly result in the instructor falling into the path of the grader's tires. Two-way radio communication is sometimes tried with little success, as students often don't understand the instructions relayed to them. The same goes for stationary simulators. While they can certainly assist with the basic familiarization of the controls, only 'seat time' and hours of experience teaches the skills motor grader operators need to become proficient.
Because becoming a skilled grader operator is time consuming and difficult, consequently the worldwide pool of experienced grader operators is in decline. So, when designing its new G900 series, Volvo's engineers decided to continue with its established modular concept - which allows the grader's cab to be removed in under half a day, without opening or contaminating the hydraulics systems in the process.
This ability to quickly remove the cab prompted Volvo to develop a two person training cab that allows the trainee operator and instructor to sit side by side. "As an instructor, I can talk comfortably with a new operator and explain exactly what is happening," says Russell Sharpe, Volvo's grader training instructor, and a man with over 30 years of experience with these demanding machines. "I can easily relate what the operator did right and illustrate some of the tricks of the trade - all while we are moving material. You can't get more 'real time' than that!"
Ensuring the trainee operator gets a 'true' grading experience, the two person cabs are fitted with the instructor seat sited off to the left, maintaining the original operator position. The cabs are subjected to the normal standards testing for ROPS and FOPS compliance for a machine weighing 27 tonnes. They are also fitted with climate control - providing a comfortable, quiet, environment that allows easy conversation while both the student and instructor ride in a standard suspension grader seat, complete with seat belts.
"With a grader expert sitting right beside the trainee, it is easy to explain the features and demonstrate them at the same time," says Henry Pietens, training manager for motor graders at Volvo. Being shown first-hand all of the features available in the G900 makes understanding them much easier - so the operator can truly extract the productivity and fuel economy advantages that are built into every G900 motor grader."
Volvo's Pat Olney sums it up this way: "Ensuring that both the student and instructor learn and teach in a safe environment is paramount. Not only does it enhance the learning experience, but does so with a positive reinforcement of Volvo's most important core value - safety."
The ability to change from a two-person cab to a standard one in less than a day means that graders can easily be reunited with their standard cabs. This is important if the grader is to be sold after accumulating significant demonstration/training hours.
"The great thing is the new grader can also be fitted with the two person training cab, and the benefits continue for the next group of students," concludes Henry Pietens.
Text: Brian Lowe