system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How tugboats can pull ships almost 100-1000 times their size.
gpt
They're designed to. It's not as if they're your uncle's powerboat- a tugboat is essentially a large engine with a hull around it. The design of the hull isn't for high speed, it's for being able to apply a lot of power to a very heavy barge or ship at low speeds. It's the same way that one locomotive can pull 50 train cars.

A tugboat has thousands of horsepower. It's the same motor you'd find in a much larger ship, put into a much smaller boat. There's no cabins or cargo area or anything like that, just the engine and the stuff to run it. They can have up to 25 times more engine power per unit weight than a normal ship.