The document outlines key costs and concepts related to construction machinery, including the evolution of machines powered by internal combustion engines and advancements in materials. It details the types of machinery, factors for equipment selection, and cost components such as ownership, operational, and overhead costs. Additionally, it discusses machinery life cycles, depreciation methods, and factors affecting productivity in construction projects.

1. Construction Machinery
Associated costs and basic concepts

2. Need for machinery
• Reducing costs
• Doing the heavy lifting
• Reducing duration of work

3. Advent of Modern machines
• Simple machines have combined overtime to form more complex
machines
• Developments of internal combustion and compression ignition
engines has replaced humans as source of power for machines
• Developments in materials such as rubber, nylon, steel etc. have
made mobile machines of today possible.

4. Parts of construction machines
• Platform
• Power pack
• Power train
• Equipment or tool

5. Types of machinery
• Earthwork – Dozers, loaders, scrapers
• Lifting – cranes, gantry, lifter
• Transportation – dump truck, pumps
• Concrete equipment – mixers, batching plant, compactors, spreaders,
vibrators

6. Choice of machinery
• Quality of work required
• Schedule
• Material to be handled
• Site conditions
• Budget
• Capacity of work
• Aim of machine

7. Categories of equipment
• Small tools and consumables: drill bits, blades etc.
• Shared equipment - fairly expensive equipment used throughout
construction process
• Task specific equipment – costly equipment used in specific stages of
construction

8. Equipment Selection - considerations
• Optimal production and within time and budget constraints
• Sufficient power and capacity
• Costs: Ownership, operating, labour, replacement, salvage
• Site conditions
• Working surface and material to be handled
• Volume and nature of work
• Labor availability
• Relations with manufacturers
• Client demands

9. Cost Components of production unit
• 1 production unit cost includes:
• Ownership costs
• Operational costs
• Overheads
• Profit

10. Overhead
• These are costs associated with running a machinery maintenance
and storage facility and the associated workforce;
• Wages of mechanics and supervisory personnel
• Clerical and records support
• Rental or amortization of the maintenance facility
• Expressed as a percentage of the total operation hours logged by the
entire fleet of equipment.

11. Ownership costs
• The cost of owning a machine whether its in operation or
remains idle.
• Components of ownership:
• Initial capital cost – cost of transporting machine to construction site
and set up cost
• Depreciation – decline in value of machine with passage of time due to
general economic decline, obsolescence or deterioration
Related concept of Salvage value – cash inflow from machine having some value
at the time of disposal
• Interest cost – capital invested in a machine annually (converted to
hourly cost)
• Insurance – insurance theft, fire damage, accident
• Taxes – cost of licenses and property tax
• Storage – cost of rent and maintenance, guards

12. Depreciation methods
• Straight line : (I-S or D)/Y
• Sum of digits: (year number/sum of year numbers)(D) cost highest in
1st year
• Declining balance: Rate of depreciation * I (constant every year)

13. Investment
• Annual amount of capital invested in a machine. Equals to Average
value x interest rate.

14. Operating costs
• Tire repair and replacement costs = 1.15 xcost of a set of tires
expected tire life in(h)
• Fuel cost = time factor x efficiency x average fuel consumption per hp
x hp x cost per gal
• Lubricants = or 10% of fuel cost
• Repairs (opposite of depreciation)

15. Equipment life
• Physical life: Machine reaches a stage where it can no longer reliably
produce. Must be abandoned or scrapped.
• Economic life: It is the time taken for the machine to produce
maximum operating profit.
• Profit life: The time period during which the machine operates at a
profit.

16. Factors affecting productivity
• Haul unit horsepower
• Haul road rolling resistance
• Haul road grades
• Haul unit loaded and empty weight
• Haul unit transmission characteristics
• Haul unit loading time
• Haul unit travel time
• Haul unit delay time
• Altitude of the project site

17. Rolling resistance is resistance offered to movement
of materials on a plain surface; often expressed in
pounds per ton of materials.

18.  The coefficient of traction can be defined as the factor by
which the total weight on the drive wheels or tracks should be
multiplied to determine the maximum possible tractive force
between the wheels or tracks and the surface just before
slipping will occur.
 Usable force = Coefficient of traction X Weight on powered
running gear

19. • Time to load a mover for load shifting will determine no of loads that
can be transferred. Longer loading time lesser will be productivity.
• Te is cycle time for loader
• Ch is capacity of a hauler
• Ce loading rate/capacity of loder