Types of cranes

Electric Overhead Traveling (EOT) Cranes:

EOT cranes travel on a pair of gantry rails mounted on gantry girders, which in turn are supported on columns on two sides of bay. The crane consists of bridge girders, end carriages, platforms, trolley assemble and long travel machinery. Machineries for hoisting motion and trolley travel(traverse motion) are mounted on trolley. The trolley moves on rails fixed on the top of bridge girders.
These cranes find their application in wide range of industry. Depending upon the need specified by the customer inquiry, the cranes are supplied with special features such as-

? 2 or 3 trolleys running on common pair of bridge girders (paper industry)
? 2 trolleys running on 2 separate pair of bridge girders (4 girder ladle cranes in steel plant)
? creep/inching speed for various motion
? planetary gear box with 2 motor drive for hoist motion (ladle cranes)
? Thyristor/variable voltage variable frequency controls for various drives.
? Hoist arrangement in 4 independent rope suspension (ladle crane)
? trolley running on the top of the bridge girder (Mono box cranes)
? permanent/detachable attachments such as, grab bucket, magnet, lifting beam, rotating beam, slab/coil tong, sheet pack lifter, ‘C’ hook, etc.
? two part trolley with rotation drive for upper trolley part (rotating trolley cranes)
? flame-proof design
? insulated hook block
? remote control either radio or infra red
? traveling type operators cabin
? PLC operation

Underslung Cranes:
These cranes are used in places where adequate space is not available between top of gantry and bottom of roof truss. These cranes run on the inner flanges on gantry girder I beams.
Goliath/Semi-Goliath cranes:
Unlike EOT cranes, Goliath cranes run on gantry rails mounted on floor level. The bridge girders are supported on e pair of legs which are supported on end carriages.
Semi Goliath cranes operate on rails mounted on shop gantry girder on one side end on shop floor on the other side.
Goliath cranes can be supplied with bridges extending beyond the centerline of rail mounted on ground to facilitate loading and unloading of material beyond crane span.
Moving Type Cantilever Crane:
These cranes commonly find their application in large steel plants. These cranes run only on gantry rail. Reaction rollers are provided to balance the moment arising out of cantilever loads. These cranes are mainly used for maintenance operation in steel plants.
Rail mounted Jib cranes:
These type of cranes have hoisting, slewing and machinery at a fixed rotating frame.
These cranes generally find their application in ports. Depending on customer’s needs, the jib luffing and hoisting drive can be designed to ensure fixed level of load during luffing operation (level luffing cranes).
Major Parts Of EOT Crane:
? Trolley Assembly
? Bridge Girders
? End Carriages
? Long travel drive mechanism
? Platforms
? Trolley power supply arrangement
? Operator’s cabin

Trolley Assembly:
The trolley assembly consists of hoist drive mechanism, trolley travel mechanism and the trolley frame. Typically the trolley frame is supported by 4 wheels which runs on rails mounted on bridge girder. For the safety of maintenance personnel the following is provided on the trolley.
? The top of trolley frame is covered with chequered
Plate/antiskid plate
? Toe guards/kick plates are provided around opening
and
? Hand rails and access ladder are provided.
The trolley frame also houses rail sweep plate, derailment guard and jacking pads.