Specifications include, but are not limited to: Keel Coolers: At least formed 8” channels, four (4) 10’ runs welded to bottom for keel coolers designed to provide adequate heat exchange for engine and generator. Chafe protection to be provided at forward ends of outboard cooler channels to protect against the occasional grounding situation. Stern Kevels: Shall be equipped with minimum of two (2) stern kevels and two (2) Bow, each at least 18” long. Engine: Tugs shall each be powered by a liquid cooled John Deere 6068 diesel engine or approved equal with a minimum 300 hp. Engine shall be mounted on isolators or equivalent. Engine shall be continuous rated to accommodate a 24 hour/7 days with 50-65% full throttle usage. Twin Disc model marine transmission compatible to Engine spec, with appropriate gear ratio equivalent to or better than existing state tugs.