Tugboats may seem the least spectacular among maritime vessels, but pound for pound, they are certainly one of the most powerful. The power of a large tug’s engine can reach up to 4.5 times the tug’s weight. This power is needed for the tugboat’s herculean task of towing and pushing vessels much larger than they are, and navigating them through all kinds of waterways.
The power of tugboats comes from large but lightweight diesel engines that drive the boat’s propellers, and allow them to go straight to full steam from an idle position. Unfortunately, these diesel engines are also a major source of pollution in coastal areas. Efforts are being made, however, to come up with greener tugboats.
Among these, the most notable to date is the hybrid tugboat that also runs on batteries. Instead of powering the boat’s propellers the conventional way, the diesel engine in a hybrid tugboat functions to charge the batteries, which in turn power the boat. The engine turns off once the batteries are fully charged. This results in lower diesel consumption and emission levels.
Exciting new efforts are also underway to build tugboats using greener types of fuel, such as Liquid Natural Gas (LNG). LNG contains less harmful constituents than diesel, and therefore inflicts less harm on the atmosphere.