Contractor Jesse Lynn Tullis of Advanced Integrated Tech prepares to attach the wiring for the Iveco marine propulsion diesel engine to the derrick boat Elizabeth's Mantis hydraulic crane. Once the crane lifts, the engine is lowered in the Corps vessel's engine room. On Oct. 9, the Norfolk District, U.S. Army Corps of Engineers derrick boat Elizabeth's "green initiative" transformation began with the installation of two new fuel-efficient and EPA-compliant marine propulsion diesel engines. The project includes two companion diesel generators, housed in sound-barrier boxes that significantly reduce noise pollution and exhaust emissions. The eco-friendly engines have a 25-year life span.