In the 1940’s the idea of mating two engines to one gearbox was born out of the US military, used during World War II for application such as landing crafts and tanks. Today, history repeats itself with Mitsubishi’s Tier 4 solution. Mitsubishi’s distributor Laborde Products coined this new idea as the “Quad”, four Tier 3 Mitsubishi Engines (S6R2-Y3MPTAW-2) churning 3,200 horsepower through two dual input, one single output gearboxes.
This solution is gaining interest as an economic way to deliver twin screw propulsion above1,600 horsepower without the use of EPA Tier 4 aftertreatment like SCR technology. The EPA rule allows for the use of EPA Tier 3 engines up to 600 kW or 803 HP without the more expensive and complex Tier 4 solutions.
The Mitsubishi S6R2-Y3MPTAW-2 was designed for heavy duty marine applications with nearly double the displacement of its competition. The advantages of this renewed innovation for the commercial marine market includes no urea, No SCR, just simple mechanical engines and a lower initial investment than the Tier 4 alternatives. The elimination of the additional cost of urea, SCR maintenance, and complexity will help to make the “Quad” a valuable alternative for vessel operators in the future.