The GD655-7 is powered by a Komatsu SAA6D107E-3 Tier 4 Final-compliant variable horsepower engine, rated at 134-165 kW (depending on gear and operating mode) and with an operating weight of 19.3 tonnes with rear ripper.Technology innovations include updates to the transmission and control improvements that make it easier to operate, for reduced operator fatigue and increased safety, as well as being factory-fitted to take any of the many 3D machine control system options available from leading third party suppliers.

According to Phil Atley, Komatsu’s National Business Manager, Government & Construction Graders, the GD655-7 grader – the first of which has just been sold to a customer in Western Australia – represents a significant technological step forward in grader design and ease of operation.

“We’re highlighting these enhanced grader control systems as putting the future at your fingertips,” he said.

These technology innovations include an all-new operator station, with features such as EPC (electronic proportional controls) for blade and ripper functions, and the option of dual-function palm controlled steering or a conventional steering wheel.

“In addition, this new grader retains our unique dual-mode direct-drive and torque converter transmission system, upgraded with a new range change and forward/reverse controls for reduced driveline shock – and again contributing to reduced operator fatigue and very long service life of transmission driveline components.”The Tier 4 Final Komatsu engine, which has been matched to the Komatsu-designed and built transmission, driveline and hydraulics, results in fuel consumption reductions of 5-15% compared with our previous models,” he said.

Standard on the GD655-7 are factory-fitted cabling, controls and bracketing for multiple makes of 3D machine control systems, allowing customers to simply install a “plug and play” kit to use with their own or a rented 3D machine control system, with no additional cabling or brackets.

“With this ‘plug and play’ installed, customers can go straight to work with a 3D GPS system from Trimble, Topcon or other leading suppliers, without having to spend money and time on preparing the machine,” said Atley.

Compared with Tier 3 predecessor engines, the GD655-7’s Tier 4 Final-compliant engine technology reduces both particulate matter (PM) and nitrous oxide (NOx) levels by 90%, while reducing fuel consumption by up to 15%.

“Fuel consumption is further reduced through increased cooling capacity, a new auto idle stop function, an improved operator interface on the machine monitoring system, and a new ECO assistance feature that encourages fuel-saving operating practices.”As with all Komatsu Tier 4 engines, it incorporates an advanced electronic control system that performs high-speed processing of all signals from sensors installed in the grader, providing total control of equipment across all conditions of use.

Engine condition information is displayed via an on-board network to the monitor inside the cab, providing all necessary operating data to the operator.

Additionally, this data can be accessed and managed via Komatsu’s KOMTRAX telematics remote monitoring system (supplied as standard on all Komatsu construction and utility machines), ensuring owners and fleet managers stay well on top of all maintenance requirements.

This also allows Komatsu to advise machine owners of upcoming service requirements, as well as providing machine health, performance and location information, as well as Fix It First Time real-time diagnostics.

Atley said the new GD655-7 grader machine retained all the benefits of its predecessor machines, while significant technology improvements contributed to increased productivity and safety while lowering ownership and operating costs.

“Komatsu graders have become recognised for their outstanding visibility to the blade, front wheels and rear ripper – and that’s been improved even more through further improvements to cab design.

Komatsu’s lock-up torque converter transmission with electronic control has been designed and manufactured specifically for Komatsu graders, providing on-the-go, full power shifting as well as inching capability and automatic shifting in higher ranges. It provides the option of automatic torque converter mode for maximum productivity in any application, with its automatic gear shifting, while manual mode gives direct drive in all gears, working the same way as conventional power shift graders, with constant machine speed, more economical operation.

An engine stall prevention function operates in manual mode, automatically changes to auto mode with a torque converter to avoid stalling, and having to restart the grader.

In addition, an electronic control engine management system combined with a new variable displacement hydraulic pump system and improved transmission and axle components have resulted in significantly improved fuel consumption.

Machine durability has been enhanced through a reinforced blade circle, plus a change to a resin in the circle wear plate material, which prevents scratches and results in longer service life.