Cummins extends mining engine power to 4,000 hp with launch of QSK95 ‘Hedgehog’

In one of the most significant mining engine unveilings in years, Cummins launched its new 16-cylinder, 4,000 hp QSK95 ‘Hedgehog’ engine at a special event in the company’s home Seymour engine plant in Indiana on November 1, attended by International Mining Editor Paul Moore as well as key industry customers from the mining, marine, oil and gas, and power generation sectors. Cummins has already achieved considerable success with the 3,500 hp QSK78 engine that was launched in 2003; such as in the Komatsu 930E and 960E trucks; Liebherr T282 and BELAZ 75600. However, the engine was one of two options for the Liebherr truck and many of the actually delivered T282B and T282C trucks have been fitted with the higher horsepower MTU 20V4000 engine; as was the Terex Mining MT6300AC truck, now part of Caterpillar’s Unit Rig line. The new engine offering from Cummins propels it into the forefront of the high horsepower market and is likely to form the basis of future ultraclass truck development. Tom Linebarger, Cummins President and CEO told the assembled group: “I am more confident about this launch than any other engine launch we’ve had.”

The engine will see first deliveries in 2014 with commercial production in 2015. The company also has plans to offer  V12, V16 and V20 natural gas powered engines, and predicts that as much as 30% of high horsepower engines will run on natural gas by 2020. In addition, there are plans to make a 20-cylinder, 5,000 hp QSK120, which would push the high horsepower engine boundaries even further. The QSK95 represents the highest-ever power output introduced by the company for severe duty-cycle operation. The 95 l displacement QSK95 is purpose-designed to provide enhanced strength for 327 t and 363 t (400 short ton) payload trucks, with the capability to increase truck speeds for climbing steep-gradient haul roads and boost hauling productivity with reduced operating cycle times. The QSK95 will be available as a global mining engine platform capable of operating at mine sites anywhere in the world and meeting all emissions standards, including Tier 4 Final in North America  by using Cummins proven Selective Catalytic Reduction (SCR) aftertreatment. The 16-cylinder QSK95 is also unique in having reached the mining power output previously available only from 20-cylinder engines. Cummins said it had spoken to 135 customers as part of the engine development, and in mining, customers were predicting that 30% of the large mining equipment market will be accounted for by 400 short ton capacity (or larger) trucks by 2015.

High power density is achieved with a hardened power cylinder featuring the strongest single-piece forged-steel piston available in the industry. Deep structural strength is provided by an all-new ductile iron skirted block. This increased strength contributes to higher engine uptime availability, extended life-to-overhaul (at least 500 h between service) and more cost-effective rebuilds. “The QSK95 is designed to meet the highest expectations in the mining industry for uptime availability, reliability and durability that will exceed all other previous engines intended for ultra-class haul trucks,” said Jason Rawlings, Executive Director – Cummins Mining Business, adding: “This combination of deep inherent strength and proven systems means that the QSK95 will be ready to provide outstanding performance on the mine site from day one. The QSK95 will fully complement the success of the QSK60 and QSK78 engines in ultra-class haul truck applications. These engines offer the widest and most flexible power choice in the industry.” The new engine will be made at the Seymour facility rather than Daventry in the UK where the QSK60 and QSK78 are built. This was decided following a review of available capacity and the high horsepower expertise at the home plant – the QSK95 ‘Hedgehog’ team included no less than 153 engineers and 20 technicians, all working secretly on the project over the past three years.

The 4000 hp output of the QSK95 engine is well within its design capabilities, with potential power increases available in the future to provide the possibility for the next generation of ultra-class haul trucks to move beyond 363 t payload capacity. The stronger engine design of the QSK95 means more reliability in-service and less to rebuild at engine overhaul, considerably reducing total life cycle costs, according to Cummins. The QSK95 will provide “an exceptionally long life-to-overhaul, capable of achieving 1.7 Mgal and above of fuel consumed before rebuild, with the added advantage of no midlife intervention required.” The Cummins next-generation Modular Common-Rail System (MCRS) enables the QSK95 to achieve high fuel-efficiency, even when operating at maximum power output. With up to 2,200 bar high-pressure fuel injection, MCRS reduces noise, offers smooth idle stability and eliminates  visible smoke across the entire operating range. Cummins’ new NanoNet^TM fuel filtration gives superior fuel cleanliness and enhances the durability of the MCRS system – an important advantage for mining engines required to operate anywhere in the world with varying fuel quality. A quad-turbocharging system brings the simplicity of a single-stage air handling system already proven on the QSK60 engine. The four compact turbochargers, one arranged for each bank of four cylinders, provide outstanding step-load acceptance and transient response. This enables the QSK95 to deliver more rapid power across the entire rpm range to improve haul truck speed at full payload capacity.

The QSK95 utilises an SCR aftertreatment system to meet Tier 4 Final low-emissions standards with a highly flexible installation package intended to replace the exhaust muffler. Depending on the application, the Cummins SCR system is capable of achieving incremental fuel savings of 5-10%. These fuel savings will reduce the cost of operation by more than the cost of Diesel Exhaust Fluid (DEF) required for the functioning of the SCR system. A major advantage of using the proven SCR aftertreatment is that the QSK95 avoids the need for using an Exhaust Gas Recirculation (EGR) system on the engine to reduce NOx emissions. The SCR system provides a simpler solution than the inherent complexity of applying EGR to high-output engines and means that no compromise is made to serviceability. As a further benefit, using SCR means that no additional heat rejection is generated by the engine, avoiding both an installation cost and space impact.