Explosion Proof Cranes

SPECIFICATION

The crane structure is manufactured from material according to EN 10025 GRADE. S275 JR. Designed to withstanding all imposed loadings, with a maximum deflection of 1/750^th of the span.

The crane is driven by a matching pair of braked motors the drive being transmitted through a direct, live axle, maintenance free, gear box via hardened and ground helical gears in a sealed oil bath. Operation is via a single reversing contactor type controller, with an automatic slow to fast speed timing device to provide smooth acceleration and a balanced tandem operation with no skidding or crabbing of the crane in any load permutation.

The proprietary series built, hoist unit would be selected from our extensive range of units which have a world wide reputation for reliability, modern design, safety and the very latest manufacturing techniques. The modular design forms a very efficient, compact & visually aesthetic unit. The hoist transmission train is a direct drive type with no coupling. The rope drum is mounted in maintenance free bearings. Located within the hoist bearer frame. The drum is accurately machine grooved to accommodate the hoisting rope in one layer. And is designed to leave a minimum of 3 (three) turns on the drum when maximum lift height is reached. A rope guide is provided to prevent slack rope and to smoothly guide the rope onto the drum. The rope is securely attached to the drum with 3 (three) rope clips.

The bottom hook block is of the safety type, having fully guarded deep grooved sheaves, running in sealed ball bearings. The hook is a forged steel single point “C” Type, mounted on a ball thrust race and fitted with a spring return safety catch.

The special non-rotating hoist rope is manufactured from high strength galvanised steel, the standard construction is 6×36+SES with a minimum factor of safety of 5:1. Over-hoist/over-lower limit switches, are provided located within the hoist control panel. The electromechanical overload devise prevents the accidental lifting of loads over the safe working load whilst still allowing lowering.

The Hoist & Travel drive motors with integral brake are totally enclosed, fan cooled, squirrel cage induction type, having class “F” insulation with “B” temperature rise, tropicalised and climate proof with a minimum electrical protection of IP55. The motors are specifically designed for crane applications for use in aggressive environments, without the need for anti-condensation heaters.

The heavy duty totally enclosed, fail safe, disc brakes are automatically and instantaneously applied when the power supply is interrupted. Brake linings are asbestos free. Electrical control of the complete crane would be from floor level via a heavy duty, weatherproof pendant control station fully mobile across the crane span to allow operation of the crane at a safe distance from the load. Galvanised tension relief cables to prevent damage to the electrical connections support the pendant. Robust hold-to-run, control buttons, one for each crane function, provide positive operation of all motions. An “Emergency Stop” button is also provided.

A watertight control panel would be mounted at one end of the crane bridge containing the complete control systems, comprising. A pair of electrically and mechanically linked contactors for each crane motion.

Main and control circuit fuses, control circuit transformer c/w the necessary protection devices to provide reduced operation of the control circuits. The contactors are AC 4 duty for high inching & plugging duty.

Power & control supplies on across the crane bridge, are carried in special galvanised ‘C’ type track systems with sealed ball bearing cable trolley’s carrying flat Neoprene cables type NYNJ.

A main current supply system, would provide the power supply along the length of the runway. Consisting off a special galvanised ‘C’ type track systems with sealed ball bearing cable trolley’s carrying special flat Neoprene cables type NYNJ. All necessary fittings and supporting brackets to connect to the runway are provided.

A high level terminal box would be provided at one end of the system, together with the necessary vertical cable, terminating in a low level, lockable Isolator switch, for mounting 1500 mm above grade, complete with a suitable gland to accept your incoming supply cable.

Prior to packing & protected for transportation, the crane would be assembled in our workshops & fully inspected & tested, according to our standard testing procedure, which would include full dimensional and functional tests of all crane operations including limit switches.