Industrial Vehicle Technology - June 2020
COOL RUNNINGS
2020-07-11 05:53:18
THE CHALLENGES OF RUNNING AN INDUSTRIAL VEHICLE IN EXTREME SUB-ZERO TEMPERATURES ARE NUMEROUS, WITH HYDRAULICS RANKING HIGH IN THE KEY SYSTEMS THAT NEED SPECIAL ADAPTATION TO ENSURE WORK DOESN’T GRID TO A HALT
In the frozen wastes of Antarctica, where social distancing is not needed as scientists work in isolation away from the mass of humanity (at the time of going to press Antarctica remains the only Covid-19-free continent), it’s more important than perhaps anywhere else in the world that computers and machines are reliable. Although mechanics and workshops to maintain industrial vehicles are usually on hand, a critical failure will take time to repair and replacement vehicles are not an option, so planning in resilience and durability is key.
Hydraulic systems intrinsically rely on specialised oil that flows under pressure. These kinds of off -highway vehicle systems are robust and able to withstand most extreme conditions. Sealed against moisture and dust they operate comfortably in both the burning desserts of the Middle East, as well as in most winter conditions across the globe. However, when cold gets really extreme, the proper functioning of hydraulics needs careful consideration.
As the mercury drops below -10°C industrial vehicle OEMs recommend that certain steps are taken to keep all parts of the vehicle functioning correctly, with hydraulics a particular focus lest smooth-flowing oil turns to thick sludge that won’t run on start-up. Such cold weather modifications are planned-in as options during the development stage of vehicles and tested in both cold weather chambers and real-world environments.
Accordingly, extreme weather adaptations were ready to roll out when the Australian government recently deployed a Manitowoc Grove RT540E rough-terrain crane, to join five others like it at Davis Station, one of the four research stations in the Australian Antarctic Programme.
At the remote Antarctic site, the RT540E is working in some of the harshest conditions in the world. Located 2,250 nautical miles southwest of Perth, Davis is the most southern station in the programme. Temperatures at the station can drop down to -60 °C. The RT540E is being used to load and unload cargo for resupply at the stations, well as construct and maintain the station’s infrastructure.
“We have two package options available: a -29°C Cold Weather Package, and a -40°C Arctic Weather Package,” says Federico Lovera, Manitowoc’s regional product manager for rough terrains. “The Cold Weather Package includes lowviscosity synthetic, arctic fluids for the engine, transmission and hydraulics.
These are specifically designed for extreme cold temperatures.
“ The hydraulic tank has ports for field installation of 240V electric hydraulic tank heaters.
Typically, these are not required if arctic hydraulic fluid is used, so their use is down to customer preference. However, for locations where temperatures get down to -40°C then they are generally included. On station, operators generally use the crane at temperatures no lower than -20 °C.”
The RT540E is a 35t capacity crane with a 31m four-section main boom, plus an optional 7.9m – 13.7m telescopic swingaway which delivers a maximum tip height of 47m. The boom incorporates a rectangular boom shape made from 100ksi steel which eliminates weight and maximises structural capacities.
Genie of the camp
Of course, Manitowoc are far from the only OEM deploying vehicles in the extreme conditions of Antarctica. Another recent new arrival to the frozen wastelands of the south is the Genie Z-45 XC Boom, deployed in 2019 to a long-term British Antarctica Survey construction project.
The boom lift is scheduled to remain onsite for five years to assist in a wide range of tasks. These notably include the expansion of mooring facilities for the new RRS Sir David Attenborough polar vessel, the extensive modernisation of the Rothera Research Station — the UK’s most important Antarctic hub — and the improvement of facilities and working conditions at other BAS research stations in the area.
While research at the station continues all year round, even at -60°C, due to the extreme wind and cold, work with machines can only take place during the summer from October to February when temperatures rise to a relatively tolerable -15°C.
“Naturally, the unit required a number of modifications to adapt to Antarctica’s extreme conditions,” says Wilco Donkersloot, account manager, at Dutch Genie distributor HDW who supplied the vehicle. “Among others, we chose a gel battery that is more resistant to freezing temperatures and has a longer lifespan. The standard battery pack was replaced by a more powerful battery offering a peak capacity of 1100CCA that we connected to a trickle charger to ensure that the maximum battery power would always be guaranteed. We also installed a 110V heating system for the oil sump and hydraulic tank heating elements to keep the engine oil and hydraulic oil at the right temperatures.”
During its five-year mission, the Genie Z-45 XC boom will be hard at work, running up an estimated 2,000 machine hours in total. “Planning ahead, we made sure that we provided ample spares for maintenance as well as parts to repair critical breakdowns that will be useful when the time comes,” says Donkersloot. “The machine was delivered just over a year ago, so it’s still early days, and communications with the research station are difficult to say the least. However, for the moment, we are delighted to say that the last we heard is that their Genie Z-45 XC boom is running reliably and work is proceeding as scheduled.”
Going underground
However, you don’t have to travel all the way to Antarctica to find extreme cold. Siberia in Russia is also famous for its freezing conditions – which are exacerbated if you are working in a tunnel beneath the surface, as four Terex Trucks TA400 articulated haulers do in the Arpatsky coal mine.
Here, temperatures can drop as low as -45°C, low enough to put even the toughest off -highway vehicle to the test.
“THE HYDRAULIC-FLUID HEATING SYSTEMS MAINTAIN AN AMBIENT FLUID TEMPERATURE WHEN THE MACHINE IS PARKED, TO ENSURE A SAFE START-UP TEMPERATURE"
“A standard machine is safe to start in ambient temperatures down to -18°C. Prolonged use in temperatures lower than this will require supplementary fluid heaters and a careful selection of compliant fluids that have the correct specifications and viscosity index to work at such low temperatures,” says Scott Pollock, senior product manager at Terex Trucks. “In the Russian mine our customer has proven that our trucks can work reliably at much lower temperatures. They have ensured that there is a vital regular inspection and maintenance programme in place to maximise uptime and productivity.”
Once again, the proper functioning of hydraulics is a key consideration, with specially designed heaters installed in tanks to ensure smooth flow and operation. “The hydraulic- fluid heating systems are third party solutions verified by Terex Trucks,” says Pollock. “These tend to be powered externally by the mains supply, suitable for the machines destination i.e. 220V or 240V systems. These systems maintain an ambient fluid temperature when the machine is parked, to ensure a safe start-up temperature.”
The drivetrain must overcome similar challenges. “Our drivetrain extreme cold weather solutions are generally approved by the engine or transmission OEM. These tend to be powered by the truck’s electrical systems on ignition. They will pre-heat the fluid and will have thermostatic control once at operating temperature,” explains Pollock.
“Other local solutions are often used in extremely cold conditions include engine radiator covers or shutter systems that reduce the airflow across the radiator core for rapid coolant heat up that then influences the temperature of the other systems. This type of system can promote fuel / coolant heat exchangers where the rapid heat up in the coolant is transferred to the fuel system.”
All round, the TA400 dump trucks – that offer a maximum payload of 38 metric tons – are proving themselves transporting coal and overburden, for up to 22 hours a day.
“The robustness of the TA400 and its ability to deliver a reliable performance in tough conditions was a big part of the reason why we chose Terex Trucks haulers over other brands,” says Dmitry Dulin, chief engineer at the Arpatsky coal mine.
BUILT FOR EXTREMES
The TA400, the largest articulated hauler on offer from Terex Trucks, has a heaped capacity of 23.3 m3 (30.3 yd3). Powered by a high performance, fuel efficient engine that develops a gross power of 331kW (444hp), the TA400 is designed to meet the demands of the most extreme operations such as quarries, mines and large-scale construction projects. The planetary gear transmission provides smooth, efficient gear shifting for optimised fuel consumption and reduced cost of operation.
The truck operators at Russia’s Arpatsky mine appreciate the TA400’s ability to climb and descend the slopes at the coal mine. “The hauler handles the downhill slopes smoothly and safely,” says Oleg Likhodumov, director of operations at the coal mine. “With the exhaust break, we don’t even need to use the brakes when going down steep hills.” The TA400’s modulating transmission retarder is coupled with an efficient exhaust brake and fully enclosed oil-cooled multidisc brakes, this provides optimum control and increased safety on steep slopes.
The RT540E is a 35t capacity crane with a 31m four-section main boom, plus an optional 7.9m–13.7m telescopic swingaway
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COOL RUNNINGS
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