Flatbed trolleys are a common form of transport in distribution environments, for moving bulk loads. A very simple design offers a basic flat platform with four casters and a fixed handle which is used to either push or pull the platform with the load on the platform. Without a flat surface it becomes an "open frame" trolley and without a handle it is a bogie or dolly.
The frame is usually fabricated steel. The primary flatbed surface can be constructed from wooden boards, plastic, steel or mesh. Flatbed casters can vary dramatically, made of solid rubber, air filled pneumatic or cast iron. The caster is generally the component on the flatbed trolley that limits the safe working capacity.
Specialised trolleys include the piano dolly, which consistently features small multi-swivel castors and a stronger than usual frame. The "U-boat" - used to move and stock goods by retailers such as grocery stores - has two high handles on opposite ends of a thin flatbed. Modern factory systems commonly track individual trolleys digitally to facilitate automated bills of lading; automated systems may have remotely operated or autonomous trolleys for transport during storage and access.
The trolley shown at right is termed "a Turntable Trolley" due to its steering mechanism. Unlike a flatbed trolley that is mounted on castors, turntable trolleys are mounted on solid axles which allows enables a much higher load capacity. The rear axles are fixed the chassis, and the front wheels are attached to a steering mechanism that allows the trolley to be turned when moved.