Versatility And Strength: Gantry Cranes
New and used gantry cranes lift objects by a hoist which is fitted in a trolley and can move horizontally on a rail or pair of rails fitted under a beam. Also called a portal crane, the gantry crane has a mechanism supported by uprights, usually with wheels at the foot of the uprights allowing the whole crane to traverse. Gantry cranes are fitted with a hoist in a trolley in order to move objects and materials along a horizontal axis. Gantry cranes can be used in industries like construction and building maintenance due to versatility and strength. Equally popular, new and used gantry cranes (also referred to as overhead travelling bridge cranes) can be designed to be fully portable.
Cranes, defined as mounted mechanical instruments used to transfer small and medium sized loads over a short distance, come in a variety of designs including the bridge crane and the gantry crane. Cranes whether fixed or mobile are driven manually or by power. The gantry crane is one of the few types of cranes that cannot be modeled as an industrial vehicle, the other is the bridge crane. Gantry cranes are used widely across a variety of industries, including: marine industry, pre-fabricated concrete, steel mills, modular buildings, wind power generation and aerospace.
The overhead travelling cranes and the gantry cranes are designed to handle heavy equipment normally used in the following circumstances: erection and maintenance operations of the main equipment of pumping stations, hydro-electric power plants, dams and irrigation systems; manoeuvring operations of stop logs and fixed wheel gates and erection and maintenance operations of radial gates. They are often supported by jib cranes when performing loading and unloading duties.
A container crane (also container handling gantry crane, ship-to-shore crane) is a design of large dockside gantry cranes found at container terminals for loading and unloading inter-modal containers from container ships. Container cranes consistent 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 on to the container's four locking points ("corner castings"), using a "twist lock" mechanism. A fully manoeuvrable version not using rails is a rubber wheeled gantry crane.
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. Another notable gantry crane is the Taisun, the world's biggest 20,000 ton crane, which is based in China.
Used gantry cranes on the market include: workstation gantry cranes, which are used to lift and transport smaller items around a working area in a factory or machine shop; rail mounted or Electrical Overhead Travelling (EOT) gantry cranes, which function similarly to an overhead bridge crane, but has rails installed on the ground and gantry-style legs to support the crane. Used gantry cranes have become a great option in these turbulent economic times.
