Transporter (MET) tractor entered service with Seabees, and later in the year with the Marines. The MK28C is a variant of the MK28. The MK28C (C - chassis) replaced Special Purpose Vehicle (SPV) types, these based on a mix of tactical and commercial truck chassis and including: water distributor, 2,000 US gallon; fuel, 1,500 US gallon; field service; asphalt distributor; earth auger. Interchangeable commercial-off-the-shelf (COTS) - or modified COTS - bodies are fitted to MK28C chassis as field circumstances dictate. Also in 2005, Oshkosh was awarded a contract to re-manufacture an initial 27 MTVRs to new configuration and with a full new vehicle warranty. On 16 May 2008 the 10,000th MTVR was completed. By late 2011 an estimated 11,135 MTVRs had been ordered, that figure including 9,221 for the USMC and 1,855 for the Navy. In FY12 the third (and final) five-year multi-year MTVR contract was awarded to Oshkosh. The final known MTVR delivery order (US$67 m for 338 vehicles; 278 Marines, 60 Seabees) was placed in September 2012, and inclusive of this order 11,359 MTVRs were ordered by the US Marines', about 1900 of these for the Navy. Orders under the final contract could be placed until June 2016. In conjunction with Pierce Manufacturing (an Oshkosh Corporation company), Oshkosh developed the MTVR MK23/25-based Hawk Extreme, a wildland firefighting water tender. This product has been sold commercially. Technical description All production versions of the MTVR are based on the same 6×6 drive configuration and utilize a chassis constructed using bolted / huck-bolted, formed channel (9.75 × 3 × 0.38 in) made of heat-treated carbon manganese steel with a yield strength of 110,000 psi minimum. The engine is located under a forward fibreglass hood. The cab seats three and is of welded aluminium extrusion construction with adhesive bonded aluminium skins. The cab folds down to reduce overall height to 98 in and from mid-2007, production vehicles are armor-ready and have air-conditioning, revised cab mounts and upgraded cab suspension. With the exception of the UK's Wheeled Tanker variants, all MTVRs are powered by a Caterpillar C-12, Advanced Diesel Engine Management (ADEM) III 11.9-litre six-cylinder diesel engine that develops 425 hp at 1,800 rpm and 1,550 ft-lb of torque at 1,200 rpm. When the central tire inflation system (CTIS) is set at 0 to 2 tons payload, engine power output is automatically reduced by around 20%. Driveline is completed by an Allison HD