Mitsubishi has slippery slope in control

The secret to the latter work is a 26-foot wide sloper blade mounted on the grader, which Grammer has adapted from an American design and refined a number of times. A key element in the success of the sloper blade was the Mitsubishi MG400 grader it was mounted on.Grammer originally operated a Mitsubishi grader for another contractor and, being mechanically minded, he got to understand the physical strength and mechanics of the machine. He advised the owner that the grader would be ideal for mounting a sloper blade on but when the owner was sceptical about this, Grammer left him in 1978 and bought his own machine, an MG400 with 7200 hours on the clock. A US design of sloper blade was used as the basis of what was built on the grader, but it was built locally incorporating some modifications specified by Grammer, with a royalty paid to the US firm for use of the design (the patent has subsequently been acquired). Grammer upgraded the roller bearings in the transmission planetary gears, but this was the only significant modification made to a machine that ended up weighing more than 21 tonnes with the sloper blade installed. Within six years his original employer was out of business while Grammer was kept busy with his machine.While other sloper blades are generally shorter and operated by a hydraulic ram at the rear of the grader, the Grammer blade is cable operated via a hydraulic winch mounted on the front frame, and pivots from a mounting point behind where the ripper box would normally be mounted. For travel the blade is stowed along the side of the grader, resting in front and rear cradles and clearing the front wheels. The pitch of the blade can be adjusted hydraulically, similarly to a standard blade. Most other blades are mounted on the side of the grader, imposing uneven stresses, but the location of the rear mounting point of the Grammer blade is one of the secrets of its success and longevity, along with the strength of the Mitsubishi steel chassis design. Another is its versatility, as it can be operated either up-slope or down-slope, so that large batters can be trimmed from both the top and the bottom. Grammer is yet to find a batter that could not be fully trimmed in this manner. While the performance of the blade in trimming irrigation channels is to be expected, its performance in road maintenance has been equally as impressive, particularly for the Walgett Shire. The sloper blade is able to pull material up out of the table drain at the same time as the underslung blade trims the road. The sloper blade can be lifted quickly when traffic needs to get past the grader.With the sloper blade able to be set at a different angle to the underslung blade, a crown can be shaped in one pass, spreading material previously recovered from each side of the road. This means the grader can do in three passes what it previously took nine or 10 passes to do in recovering gravel from the table drains and reshaping the surface. This efficiency means that on a good day nearly 30 kilometres of road can be maintained.The grader has also been used for construction work and in its first test it built up the height of 20km of road by around 500mm in three weeks. One side of the road was built up, with windrows placed on the other side to ensure traffic travelled over the built-up section and compacted it while the other side was worked on.Grammer bought another grader, a Mitsubishi MG430 grader, in 1998, but the MG400 continued to work with another operator. Its engine was replaced at 40,000 hours because of corrosion from electrolysis. It was sold to the other operator and now has more than 50,000 hours on it.The MG430’s hydraulics had to be upgraded to allow it to operate effectively with a sloper blade (Mitsubishi was a willing partner in this). The other operator has subsequently bought an MG460 which appears to have returned to (and exceeded) the specifications of the MG400. Mitsubishi remains the only brand of grader that Grammer feels can handle the demands of sloper blade work. Despite the machine weight and the hard work that it does, the grader averages 15 litres per hour of fuel, which is better than younger graders doing lighter work. Often material is flowing over the top of both the underslung blade and the 700mm high sloper blade. The sacrifice of the rear rippers to provide a mounting point for the blade has not had a major impact, as the weight of the machine allows it to gouge material out with the underslung blade. However work is faster if another grader pre-rips the road as required.Grammer had previously ordered an MG460 for himself but the order was put on hold when the prolonged drought reduced the volume of channel maintenance work. The work has picked up again, however, and a second MG460 remains a possibility.

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