A key reason for the global success the Grove GMK brand has experienced for the past 40 years is in main due to the unique features and benefits of the MEGATRAK® suspension system. John Stewart, VP and General Manager for Manitowoc Cranes Australia walks us through the development history of the Grove GMK brand.
According to Grove, the MEGATRAK suspension system is the optimum driveline available on the market today. It’s revolutionary design features an independent hydro-pneumatic system with hydraulic lockout acting on all wheels. The suspension can be raised 170 millimetres or lowered 130 millimetres both longitudinally and transversely and features an automatic leveling system for on-highway travel.
Key benefits of the MEGATRAK include:
• Unmatched highway performance
• Excellent job site manoeuvrability with all-wheel steering
• Commonality among almost all models
• A driveline that remains aligned at all times
• A steering linkage system that is protected against damage
• Constant tyre contact for equal tyre wear
• Reduced maintenance
The MEGATRAK independent suspension, all-wheel steering system and steer by wire technology provides increased ground clearance, adjustable suspension and reduces tyre-wear to provide maximum manoeuvrability in all terrains.
The MEGATRAK suspension was initially developed by Krupp, launched at Bauma, Germany in the late 1980s and was a real step change in the crane industry in the early 1990s.
“MEGATRAK provides greater ground clearance because the differential is actually pinned to the chassis. The system is very much like an aircraft’s landing gear moving up and down as it drives. Back in the early ‘90s there were a few teething issues, that were quickly resolved. The channel on the original wishbone system wasn’t big enough and a number of cooling holes were added to provide more air flow to help with cooling. Another issue related to the lack of greasing customers were undertaking so an automatic lubricating system was included on every crane. With a couple of materials changed and small dimensional alterations, MEGATRAK became a ‘suspension rockstar,’” said John.
With MEGATRAK each wheel is independent so when one side of the crane oscillates there isn’t an axle causing both sides of the crane to be affected. This provides for better wear on tyres and better efficiencies all the way around.
“If the crane hits a rock for example, you only have worry about a drive shaft, everything else still works. If you damage the differential, it can be removed on the site, and you can still move the crane. Whereas if you damage a solid axle, it has to be floated to a repairer,” said John.
MEGATRAK allows the crane to be lighter due to there being no axle housing.
“With the weight saved on the axle housings you can put that material in other places. We are using it for longer booms with stronger capacities. It allows for higher tensile steels in the boom. We were the first to install laser welded booms, which saved enormous amounts of weight and allowed us to have wider and deeper booms and our design provides more capacity and less deflection.
“We are able to provide customers with longer booms. Our 150 tonne features 69 metres which is over two metres longer than our competitors in the same package with the same weight. Also, with a four metre limit on the travel height of cranes, the MEGATRAK system allows for a lower chassis, flat deck which is not only safer but also allows for deeper booms within the overall height,” said John.
MEGATRAK provides the opportunity to include other weight-saving features which includes the carrier frames.
“Our carrier frames are made from one large piece of steel which we wrap and bend which means it has less weight compared to welding plates of steel together, it’s a very different approach to manufacturing compared to our competition.
“It provides us with more advantages in terms of weight. If we can save 20 kilos of welding and reinforcements per metre of chassis, that’s up to 20 kilos x 20 metres, weight we can put into other areas of the crane which will enhance performance and lifting capabilities,” said John.
Another feature of Grove GMK’s DNA is Twin Lock boom pinning.
“When you look at the design of the boom, its intention is to lift and as it does there’s a neutral area that doesn’t experience as much force. Some competitors use a large single pin and a hole in the tension member at the top of each section, whereas we have two smaller horizontal pins in the neutral zone, which is an advantage, certainly in terms of boom loading and maintenance,” said John.
Remembering Grove GMK’s DNA
“During conversations with new customers, we obviously highlight the features and benefits of the
Grove brand and include the MEGATRAK® system in the conversation, frequently the response is ‘Oh yeah, what’s that?’
“We think it is important to remind the industry that the MEGATRAK system is unique to Grove GMK and it has allowed our engineering teams to optimise the design of today’s all terrain models.
“We will be releasing an exciting new model during ConExpo in March which would not have been possible without MEGATRAK.”
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