Used Cranes for Sale — 2,810

Characteristics of Cranes

Cranes are material handling equipment designed for lifting and moving heavy loads. They are basically used to move loads over variable ( horizontal and vertical) paths within a restricted area. They are preferred over other material handling equipments when there is insufficient or intermittent flow volume, for example when the use of a conveyor cannot be justified in the movement of goods. Cranes are more flexible in the transportation of material than the conveyors but at the same time not as flexible as industrial trucks. Loads handled by these machines are more varied with respect to their shape and weight than those handled by a conveyor. Mostly hoists are utilized by cranes for vertical movement, although manipulators can be used if precise positioning of the load is required

History & Development of Cranes

They have been used since ancient times, the chimney or fireplace cranes were used to turn the pots and kettles on the fire, while the height was governed by a trammel hook. In ancient Greece, the cranes were widely used and it can also be quoted that the construction of these machines probably begun with the ancient Greeks. They played an important role in the construction of tall buildings & temples. During the middle ages, they were introduced for lifting, loading and unloading ships in harbours as well as aid in their construction. It was in harbours where they developed rapidly due to the importance of trade. Later, handling machines were built heavily with the use of tread wheels, which permitted lifting of much greater weights. Nowadays machines employ internal combustion engines or electric motors or hydraulic systems to provide increased capability in lifting weights. Additionally there are the mobile ones which are mounted on trucks. When the provision of power is a major concern, manual cranes come into the picture. Today these are used extensively within the construction industry with a host of different varieties from tower to mobile cranes.

Types of Cranes

Though there are many classifications based on the purpose of use, the three main types used in industrial environments are:

• Bridge Cranes
• Gantry Cranes
• Jib Cranes

Bridge Cranes : It consists of one or two horizontal beams supported between fixed rails on either end. The hoist moves along the length of the bridge, and the bridge moves along the rails. The x- and y-axes movements are provided by the above said movement and the hoist provides motion in the z-axis direction. In the bridge crane, vertical lifting is due to the hoist and horizontal movement of the material is due to the rail system. They are used in heavy machinery fabrication, steel mills, and power-generating stations. The major advantage of this handling machine is that it enables three dimensional handling with ease & precision. Top riding and underhung are the two versions . Top riding is used for lifting heavier loads but the underhung cranes are the most versatile ones as they can also interface with other material handling systems.

Gantry Cranes : These types have one or two vertical legs which support the horizontal bridge. The bridge of the gantry crane has one or more hoists that help in vertical lifting. Gantries are available in a variety of sizes. Double gantry, half gantries and cantilever gantries are the different types of gantries. As the name suggests, double gantry cranes have two legs. In a half gantry crane, there is a single leg on one end of the bridge, and the other end is supported by a rail mounted on the wall or any other structural member. The bridge in a cantilever gantry crane extends beyond the length of the support legs. These types are generally used outdoors where it is not convenient to erect an overhead runway.

Jib Cranes : It consists of a hoist mounted on a horizontal cantilever beam which is supported by a vertical column. The horizontal beam is pivoted about the vertical axis formed by the column to provide a horizontal sweep for the machine. The beam acts as a track for the hoist trolley to provide radial travel along the length of the beam. The horizontal sweep of a jib crane is circular or semi-circular. The hoist provides vertical lifting and lowering movement. Hoist which is used for lifting can move along the entire length of the jib. The arm of the jib machine can rotate up to 360°

Other commonly used types:

Stacker Cranes are more or less similar to bridge cranes except that, instead of a hoist, they use a mast with forks or a platform to handle unit loads. It is ultimately a crane with a fork lift type mechanism used in automated warehouses. It moves on a track in an aisle of the warehouse and the fork can be raised or lowered to any of the levels of a storage rack and can be extended into the rack to store and retrieve the products. It is used especially when more height has to be reached.

A loader crane is a hydraulically-powered articulated arm fitted to a truck or trailer, and is mainly used for loading or unloading of the vehicles.

Bulk-handling cranes are designed to carry a shell grab or bucket, rather than using a hook or a hoist. They are used for bulk goods, such as industrial liquids, coal, minerals, etc.

Manufacturers of cranes

There are many cranes for sale by many manufacturers on the market, including used crane dealerships, specialising in certain industries while others are more general. Some of the world famous manufacturers are: DEMAG, ABUS, STAHL, SENNEBOGEN Maschinenfabrik GmbH, GORBEL, MANITOWIC, LIEBHERR, SARENS GROUP, AMERICAN CRANE & EQUIPMENT and KCI.

One in ten of the cranes produced throughout the world come from Konecranes, a Finnish manufacturer, making them a world leader in crane sales. No matter the manufacturer, though, there are many used craneson the market and regular crane auction sales showcasing second hand cranes and used crane parts.

Here is the list of top crane manufacturers worldwide.