A portainer (also known as a gantry crane, container crane, container handling gantry crane, quay crane, ship-to-shore crane, STS crane or a dockside crane) is a very large crane used to load and unload container ships, and only seen at container ports. The term Portainer is a registered trademark of Paceco Corp. who is generally believed to have delivered the first Container Crane to a marine terminal in Alameda, CA in the 1960s. Container cranes have a special lifting device called a spreader bar (also known as Spreader or Expandable Spreader) for loading and discharging of containers. The spreader bar has four or eight (twin-lift) twistlocks which lock and unlock into the cornercastings of the containers and can be used in 20', 40', or 45' positions depending on the size of the containers. The boom of the crane allows containers to be lifted from the hold and moved toward the centre of the crane, then lowered to the dockside below. The whole crane runs on two railways so that it can traverse (gantry) along the dock (also known as Wharf).

There are two common types of container handling gantry crane: high profiles (luffing boom) where the boom is hinged at the waterside of the crane structure and lifted up in the air to clear the ships for navigation; the second type is the low profiles shuttle boom crane where the boom is shuttled/pulled towards and over the ship to allow the trolley to load and discharge containers. The high profile cranes are the toller of these which are shown in the pictures.

Amongst the major designers and manufactures of these cranes are ZPMC, Noell, Kone, Kocks, IMPSA, Paceco, Hyundai and Samsung.

Container Cranes are generally classified by their lifting capacity, and the size of the container ships they can load and unload containers. A Panamax crane can fully load and unload containers from a container ship capable of passing through the Panama Canal. A Post-Panamax crane can fully load and unload containers from a container ship too large to pass through the Panama Canal. The largest modern container cranes are classified as Super-PostPanamax. A modern container crane capable of lifting two 20 foot long containers at one time will generally have a rated lifting capacity of 65 Long Tons from under the Spreader. Post-Panamax cranes weigh approximately 800-900 Long Tons while the newer generation Super-PostPanamax cranes can weigh 1600-2000 Long Tons.

The crane is driven by an operator that sits in a cabin suspend from the trolley. The trolley runs along rails that are located on top or sides of the boom and girder. The operator runs the trolley over the ship to lift the cargo which generally are containers. Once the spreader latches (locks) on to the container with the Spreader, the container is lifted and moved over the dock and placed (discharged) on a truck chassis (trailer) to then be taken to the storage yard. The crane will also lift containers from the chassis to store (load) them on to the ship.

The cranes are power by two types of power source; diesel engine driven generators which are locate on top of the crane or direct electric power from the dock. The most common is electric power from the dock (also known as shore power) in which case the electric source can be from 4000 up to 12000 volts.

Lorries and containerlifters, also known as straddle-carriers, can manoeuvre underneath the base of the portainer crane, and collect the 'boxes'. They are designed to allow rapid cargo operations between the dock and storage yard.

Two famous gantry cranes built in 1974 and 1969 respectively, are Samson and Goliath, which reside in the largest dry dock in the world in Belfast, Northern Ireland. Each crane has a span of 140 metres and can lift loads of up to 840 tonnes to a height of 70 metres, making a combined lifting capacity of over 1,600 tonnes, one of the largest in the world.

Commercial item transport and distribution | Portalkran | Portique de manutention | Suwnica bramowa