Examining the Types of Cranes
While there are many different types of cranes, all of them are engineered to be safe, reliable, and to be able to lift the capacity you need, depending on the type and model that you choose. When choosing the type of crane that you need you must not only consider the weight that needs to be lifted, but also the radius at which the object must be lifted up at. This significantly changes the loadings imposed on the crane, and thus you will have to adjust the size and model to suit. Also, remember that the loads imposed on the crane must be transferred to the ground; therefore you must ensure that the ground is capable of maintaining its structural stability while the additional loads are imposed on it which include not only the weight of the crane but also the object it is lifting, the lifting gear (chains, slings).
Here is a look at some of the types of cranes you might come across and how they are generally used:
1. Mobile Crane (Wheel based or truck mounted) – One of the most powerful pieces of equipment in the construction business, mobile cranes are used for building and maintaining highways, bridges, buildings, pipelines and towers. They have a maximum height of about 400 feet and can lift hundreds of thousands of pounds.
2. Tower Crane (Hammerhead, Luffing, or Derrick King Crane) – Most major construction sites have tower cranes. They often rise hundreds of feet into the air and can reach out just as far. They are used to lift concrete, steel, large tools, and a variety of other building materials.
3. Marine Crane – Marine Cranes are most often found either on the shore line or attached onto the boat or ocean vessel themselves. They are used in the lifting and placing of boats into the water from shore, or if attached to the vessel it is used in the assistance of lifting and placing objects on board into the water or back on shore. The come in a variety of sizes and can be found with the following jib options: Foldable knuckle boom, stiff boom crane, or telescopic.
4. Gantry Crane (cantilevered, Overhead traveling, Semi Gantry, Wall mounted) – Gantry cranes have become a popular alternative to overhead bridge cranes. They are similar to bridge cranes, except that they run on a runway at the floor level. The bridge is supported by a pair of rigid steel legs, carried by a pair of end trucks along the floor level runway.
5. Electric Hoist (mounted or travelling) – An electric device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps.
6. Straddle Cranes (travelling or mounted) – A straddle crane or carrier is used in port terminals and inter-modal 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.