Most of the construction projects involve labour intensive work which is to be handled by men and the heavy equipment designed for doing the work undersigned. It is difficult for workers to accomplish all things in a project and so there comes the need for machines particularly the construction machinery that is widely used nowadays almost everywhere in the world.
For speedy and economic construction of a project, appropriate choice of equipment is of utmost importance for civil engineers. The versatile range of equipment available commercially involves the decision of the project management team.
There are 10 basic pointers that are considered in selection of suitable equipment. They are as follows:
1. Use of Available Construction Equipment
Where the full utilization of new equipment for its entire working life is not foreseen, or its utilization on further projects is uncertain, it may be desirable to use existing old equipment even if its operation is somewhat more expensive. The depreciation cost of the new machine is likely to be high, and this would raise the owning cost of the equipment and thus the unit cost of work.
2. Suitability for Job Conditions
The equipment chosen should suit the conditions of the job, soil, valley, working conditions and climate of the region.
3. Uniformity in Type
A minimum number of types should be acquired so that there is uniformity in the type of equipment on a job. A common type of engine should be selected for the different types machines such as excavators, dump trucks, tractors and scrapers that are on the project.
4. Size of Construction Equipment
Larger equipment gives higher output on full load, but its cost of production on part load is usually greater than that of smaller units working on full load. Larger equipment needs correspondingly larger size of matching units, and shutting down of one primary unit may render several other large units idle.
Transportation to sites is generally difficult and costly. Servicing, maintenance and repair facilities have to be greater for larger units. However, larger machines are usually more sturdy and suitable for tough working conditions. It is desirable to have equipment of same size on the project.
5. Use of Standard Construction Equipment
Standard equipment is commonly manufactured and is available. Such equipment is manufactured in large numbers and so readily available and moderately priced. Spare parts of standard equipment are easily available and are less costly. After the work is over, disposing off standard equipment and its spare parts is generally easier than disposing off non-standard or specialized equipment.
6. Unit Cost of Production
The economics of equipment is one of the most important considerations in the selection of equipment. When calculating owning cost, all items of expenses, like freight, packing and forwarding, insurance, erection cost, commissioning, etc. should be included with the price paid to the supplier.
7. Availability of Spare Parts
The availability of spare parts at reasonable costs during the entire working life of the equipment should be ensured while selecting a particular type or make of equipment, especially of imported equipment. Downtime due to shortage of spare parts commonly accounts for long idle periods during the working life of equipment. If specialists are needed, their availability should also kept in mind.
8. Versatility
The machine selected should, if possible, be able to do more than one function and should be inter-convertible wherever possible.
9. Selection of Manufacturer
It is good to have equipment of the same manufacturer on a project as far as possible and to have minimum number of different makes of equipment. The quality and commitment of local dealers is important. They should be sincere and capable of extending prompt after sales service.
10. Adaptability for Future Use
If the machine is required to work for only a part of its useful life then possibility on of disposing it off or its employment some other job should be considered. Obsolescence of the machine should not be overlooked.