Portainer
Encyclopedia
A container crane is a type of large dockside
Dock (maritime)
A dock is a human-made structure or group of structures involved in the handling of boats or ships, usually on or close to a shore.However, the exact meaning varies among different variants of the English language...

 gantry
Gantry crane
Gantry cranes, bridge cranes, and overhead cranes, are all types of cranes which lift objects by a hoist which is fitted in a hoist trolley and can move horizontally on a rail or pair of rails fitted under a beam...

 crane
Crane (machine)
A crane is a type of machine, generally equipped with a hoist, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of...

 found at container terminal
Container terminal
A container terminal is a facility where cargo containers are transshipped between different transport vehicles, for onward transportation. The transshipment may be between container ships and land vehicles, for example trains or trucks, in which case the terminal is described as a maritime...

s for loading and unloading intermodal container
Intermodal container
An intermodal container is a standardized reusable steel box used for the safe, efficient and secure storage and movement of materials and products within a global containerized intermodal freight transport system...

s from container ship
Container ship
Container ships are cargo ships that carry all of their load in truck-size intermodal containers, in a technique called containerization. They form a common means of commercial intermodal freight transport.-History:...

s.
Container cranes consist of a supporting framework that can traverse the length of a quay or yard, and a moving platform called a "spreader". The spreader can be lowered down on top of a container and locks onto the container's four locking points ("cornercastings"), using a twistlock
Twistlock
A twistlock and corner casting together form a standardised rotating connector for securing shipping containers. The primary uses are for locking a container into place on container ship, semi-trailer truck or railway container train; and for lifting of the containers by container cranes and...

 mechanism. Cranes normally transport a single container at once, however some newer cranes have the capability to pick up two to four 20-foot containers at once.

Types

There are two common types of container handling gantry crane: high profile, where the boom is hinged at the waterside of the crane structure and lifted up in the air to clear the ships for navigation, and low profile, where the boom is shuttled towards and over the ship to allow the trolley to load and discharge containers. Low profile cranes are used where they may be in the flightpath of aircraft such as where a container terminal is located close to an airport.

Sizes

Container Cranes are generally classified by their lifting capacity, and the size of the container ships they can load and unload containers.
Panamax: A "Panamax
Panamax
Panamax and New Panamax are popular terms for the size limits for ships traveling through the Panama Canal. Formally, the limits and requirements are published by the Panama Canal Authority titled "Vessel Requirements"...

" crane can fully load and unload containers from a container ship capable of passing through the Panama Canal (ships 12–13 containers wide).
Post Panamax: A "Post-Panamax" crane can fully load and unload containers from a container ship too large (too wide) to pass through the Panama Canal
Panama Canal
The Panama Canal is a ship canal in Panama that joins the Atlantic Ocean and the Pacific Ocean and is a key conduit for international maritime trade. Built from 1904 to 1914, the canal has seen annual traffic rise from about 1,000 ships early on to 14,702 vessels measuring a total of 309.6...

 (normally about 18 containers wide).
Super-Post Panamax: The largest modern container cranes are classified as "Super-Post Panamax" (for vessels of about 22 or more containers wide). A modern container crane capable of lifting two 20 feet (6.1 m) long containers at once (end-to-end) under the telescopic spreader will generally have a rated lifting capacity of 65 tonnes. Some new cranes have now been built with 120 tonne load capacity enabling them to lift up to four 20 feet (6.1 m) or two 40 feet (12.2 m) containers. Cranes capable of lifting six 20-foot-long containers have also been designed. Post-Panamax cranes weigh approximately 800–900 tonnes while the newer generation Super-PostPanamax cranes can weigh 1600–2000 tonnes.

Operation

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 locks onto the container, the container is lifted and moved over the dock and placed on a truck chassis (trailer) to then be taken to the storage yard. The crane will also lift containers from chassis on the dock to load them onto the ship.

Straddle carrier
Straddle carrier
A straddle carrier is a non road going vehicle for use in port terminals and intermodal yards used for stacking and moving ISO standard containers. Straddles pick and carry containers while straddling their load and connecting to the top lifting points via a container spreader. These machines have...

s, sidelifts or container lorries
Truck
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...

 then manoeuvre underneath the crane base, and collect the containers—rapidly moving the containers away from the dock and to a storage yard.

Power

The cranes are often powered by two types of Power Supply
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...

; by diesel engine driven generators which are located on top of the crane or by electric power from the dock. The most common is by electric power from the dock (also known as shore power) The AC Electric power transmission
Electric power transmission
Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...

 source can range from 4,000 up to 13,200 volt
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...

s, but is not exclusive.

History

Cranes were used in harbors starting in the middle ages – see crane: harbor usage and list of historical harbour cranes.
Modern intermodal containerization
Containerization
Containerization is a system of freight transport based on a range of steel intermodal containers...

emerged in the mid 1950s, emerging from transport strategies developed in the Second World War and the Korean War, and specialized cranes parallelled developments in containerization.

In popular culture, container cranes are occasionally called AT-AT cranes due to their resemblance to AT-AT walkers in George Lucas's Star Wars films, although Lucas denies their inspiration .

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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