Ships that pick up cargo from any port and travels anytime are called

Ships that pick up cargo from any port and travel anytime are known as tramps.

Tramp ships are like the "taxis" of the sea. They do not have a fixed schedule, route, or a fixed rate of charge. Instead, they go where cargo is available, which might mean visiting multiple ports at irregular times. They 'tramp' around, picking up loads wherever and whenever there is a need. This is different from other types of ships, such as liners, which operate on fixed schedules and routes.

Tramp shipping is very flexible and can cater to sudden changes in supply and demand, making it ideal for carrying bulk cargoes, like coal or grain, which might not be available regularly or may need prompt transportation.