Tugboat
A tugboat is a small, powerful and strongly-built marine vessel, designed to manoeuvre large ocean-going ships to be able to dock at port. They are also used to tow barges, disabled ships, or other equipment.
Tugboats are usually powered by large diesel engines, which typically provide the ship with 750 to 3000 horsepower (500 to 2,000 kW). Most tugboats are less than 40 metres long, but they can be as large as 70 m.
Larger tug boats (used in deep waters) can have horsepower ratings up to 25,000 hp (20,000 kW).
The hull of a tugboat is resilient, and is often padded with tires to protect it and the ships it moves from damage.
The powerful engine, and tough construction, make conversion into a type of ice breaker easy, (although this rarely is done).
