Facilitator's Question

What are the constraints of crane and hoist in operations?

ANS:
The constraints of hoist is that there is a need take the weight usage into consideration. For example, package hoist is most suitable for light to moderate usage. When handling with heavy usage, we must use built-up hoist. There is also a need to minimise ratio of dead-weight to payload of the handling equipment.

The major constraint of jib crane is that it is stationary and cannot be moved easily from one work area to another. It is designed for positioning a work piece or tool, rather than for moving a product along in the work flow like an overhead crane.

It is also unsuitable to use when there is a need for precise locating of heavy loads, a large area of hook coverage, or frequent use for heavy loads. Another disadvantage is that the hook coverage is limited to the boom length (typically a maximum of 20 ft). The hook operates along a boom which rotates about a fixed point.

Whereas for bridge cranes or for all cranes, the constraint is the problems encountered when operating it. Problems such as crane travelling too far before stopping as electric motor brakes are being used, like most cranes, the brake pads haven't been replaced. They require replacing or adjusting every 3 months.

Other problems include bearings wearing out too soon, parts availability problems, and brakes wearing out or not working properly.