Part 3: Builders Plant
General Considerations ~ items of builders plant ranging from small hand held power tools to larger pieces of plant such as mechanical excavators and tower cranes can be considered for use for one or more of the following reasons :-
Reduction in overall construction costs.
Carry out activities which cannot be carried out by the traditional manual methods in the context of economics.
Eliminate heavy manual work thus reducing fatigue and as a consequence increasing productivity.
Replacing labour where there is a shortage of personnel with the necessary skills.
Maintain the high standards required particularly in the context of structural engineering works.
Economic Considerations ~ the introduction of plant does not always result in economic savings since extra temporary site works such as roadworks, hardstandings, foundations and anchorages may have to be provided at a cost which is in excess of the savings made by using the plant. The site layout and circulation may have to be planned around plant positions and movements rather than around personnel and material movements and accommodation. To be economic plant must be fully utilised and not left standing idle since plant, whether hired or owned, will have to be paid for even if it is non-productive. Full utilisation of plant is usually considered to be in the region of 85% of on site time, thus making an allowance for routine, daily and planned maintenance which needs to be carried out to avoid...