Familiarization with Construction Equipment [7 Hours]

4.1 Advantages and Disadvantages of Using Equipment 207920772075207420732070

Advantages of Using Equipment in Construction

1. Higher Productivity: Equipment increases the rate of output manifold compared to manual labor.
2. Reduced Overall Cost: For large-scale projects, per-unit cost reduces despite high initial investment.
3. Activities Impossible Manually: Pile driving, tunnel boring, deep excavation, heavy lifting all require equipment.
4. Adverse Conditions: Equipment works underwater (dredgers), underground (TBM), at heights (cranes), and in harsh weather.
5. Better Quality: Machine mixing, compaction, and finishing produce uniform quality.
6. Reduced Fatigue & Hazards: Eliminates health hazards; equipment is free from social and emotional factors.
7. Labor Shortage: Maintains production rate even when labor is scarce.
8. Safer & Cleaner Sites: Mechanized operations maintain safer and cleaner construction sites.

Disadvantages of Using Equipment

1. Heavy Investment: Equipment cost = 25–40% of total project cost.
2. Breakdown Delays: If a critical machine breaks down, the entire operation halts.
3. Skilled Operators Required: Only trained labor can operate, commanding higher wages.
4. Maintenance Cost: Regular maintenance, repairs, and spare parts inventory are expensive.
5. Environmental Impact: Noise, air pollution, vibration, and high fuel consumption.
6. Unemployment: Large-scale mechanization displaces unskilled labor.
7. Disposal Problem: Reselling or disposing old equipment after project completion is difficult.
8. Fire Risk: Electric tools can cause short circuits which may result in fire.

• Construction industry uses different types of equipment for different purposes
• Types: earthwork, transportation, aggregate production & handling, concrete production, road pavement, tunnel construction, hydraulic construction

Equipment classification helps in:

• Identifying equipment and verifying stock
• Locating spares and recording repairs
• Accounting for costs and indexing catalogs
• Logging performance and monitoring effectiveness
• Estimating output and planning procurements

Advantages of Using Equipment 2079 2075 2074 2073

• Large and complex works can be carried out easily
• Faster rate of work progress can be achieved
• High quality of work can be achieved
• Equipment can work in adverse weather, climatic and topographic conditions
• Reduces manual labor requirement
• More uniform output quality

Disadvantages of Using Equipment 2079 2077 2075 2074 2073 2070

• Consumes a considerable amount of investment, increases project cost
• Hiring of equipment depends on availability
• Less environmentally friendly than green technology
• Requires skilled operators
• Maintenance and repair costs
• Fuel and energy costs
• May not be suitable for small-scale works

4.2 Equipment for Excavation 207920762075207420722071

• Earthwork in excavation is the basic task in any civil engineering project
• Excavation may be at surface or below the surface
• Done for foundation or for collection and production of construction materials

a. Excavator 2071

• Has a hoe with teeth-attached bucket at its back
• Capable of excavating to a depth
• Teeth-attached bucket also loads excavated material directly to transporting vehicle
• By changing the bucket, can be converted to driller, power shovel, etc.

• Classified by digging motion: Upward motion = Shovel; Downward motion = Hoe

b. Dozers / Bulldozer

• Versatile mechanical instrument for excavating in both firm and loose soil
• Can work in worst conditions — waterlogged and loose soil where other equipment cannot operate

Uses:

• Pilot road and site clearance
• Remove vegetation, bush and shrubs
• Remove topsoil
• Move tree stumps
• Shallow excavation
• Push material over short distances

c. Power Shovel / Loaders 2079 2076

• Has a square tilting bucket on the end of a moveable arm
• Loader assembly may be removable attachment or permanently mounted
• Used to excavate and load into truck or onto conveyer belt
• May be crawler mounted or pneumatic wheel mounted

d. Backhoe Loader 2075

• Falls under the group of power shovel
• Has a long handle and one digging unit
• Also known as: hoe, backhoe, back shovel, pull-shovel
• Advantageous for digging below ground level (trenches, ditches) with precise depth control
• Small version with dipper attached on rear surface = backhoe loader

e. Dragline 2079 2074

• Works on soft-to-medium soil
• Can handle digging wet material or underwater excavation
• Used for hauling soil from the pit
• Mounting types: track-mounted, wheel mounted, or truck-mounted

f. Clamshells

• Named from the shape of its bucket — a hinged double shell
• Performs digging, excavation, and lifting material
• Handles loose material: sand, aggregate, gravel, crushed stones
• Used for lifting material from deep foundations (cofferdam, pier foundation, manholes)
• Can lift material vertically
• Has characteristics of both dragline and cranes

g. Trenching Machines

• Special machines designed to dig trenches
• Used for laying pipelines, sewer ditches
• Generally crawler mounted to distribute weight over greater area

h. Scrapers

• Capable of cutting, excavating, loading material in its bowl and discharging in uniform layers
• Types: self-propelled or tractor-pulled
• Mounting: self-propelled or rubber tire mounted

i. Graders 2074 2072

• Equipment meant to grade surfaces and large areas
• Teeth attached to blade scarify earth surface to loosen material
• Material shifted forward or to sides by grading blades
• Blade can rotate up to 270° — making it unique
• Also known as motor grader

Classified in four types:

• a) Light Grader
• b) Medium Grader — 10-12 tons
• c) Heavy Grader — 17-24 tons
• d) Very Heavy Grader

j. Power Jack Hammers and Pneumatic Drills

• Equipment used to drill holes in rock
• Used to excavate hard rock by drilling and blasting method
• Drilling bit is mounted over the Jack hammer

Very useful for:

• Drilling holes in rock for blasting and clearing
• Cutting materials with the help of pneumatic circular saws and chains
• Boreholes in timber for jointing them to make timber structure
• Running air-operated centrifugal pumps at the construction site

Comparison: Wheel vs Crawler Mounted Equipment

Comparison of Excavation Equipment

4.2b Equipment for Transportation 208020772074

a. Trucks

• Available in many types and capacities
• Used for transporting construction materials at site
• Includes normal trucks and dumping trucks
• Dump trucks: 2-axle and 3-axle types
• Common type “tippers” are readily available and economical

b. Dumpers

• Larger capacity than trucks
• Can work in adverse conditions
• Types: rear tipping or bottom dumping

c. Rail Wagons

• Used for transportation of bulk materials along rail lines
• Transport large quantities: sand, aggregate, crushed stones
• Economical for long distances where rail lines are available

d. Mini-Dumpers

• Small dumpers used for small construction sites
• Lower capacity but can maneuver in tight spaces
• Useful inside buildings for small volume work

e. Loaders

• Front-end loaders are also excavation equipment
• Useful for loading material onto trucks and dumpers
• Used for material handling and transportation

f. Belt Conveyor

• Moving belt running over a series of rollers to carry material over a given path
• Speed and width of belt determine capacity
• Used for bulk material transport in crushing plants, concrete plants, etc.

g. Bucket Conveyor

• Series of buckets mounted on chains or belts
• Transports material vertically or at steep angles
• Used for elevating materials from lower to higher levels in aggregate/concrete plants

h. Ropeways

• Wires hung from pylons through which material transported in carriers or buckets
• Used in hilly terrain where road access is difficult for transporting construction materials

Comparison of Transportation Equipment

4.3 Equipment for Compaction 2081208020792078207720742072

• Compaction = process of densification of soil by application of mechanical energy
• Purpose: increase soil density and strength

a. Smooth Wheel Roller (Static Roller)

• Also called three-wheel rollers
• Consists of a large roller drum in front and two smaller rollers at rear
• Available in 6 to 16 tons capacity
• Used for compaction of granular soils and finishing of road surfaces

b. Sheep Foot Roller

• Steel drum with projecting legs (feet) attached to its surface
• Feet knead and compact the soil
• Very effective for cohesive soils (clay)
• Available in 5-ton to 20-ton capacity
• Projecting feet penetrate into soil and compact from bottom up

c. Grid Roller

• Cylindrical heavy roller made of a network of steel bars forming a grid pattern
• Used for crushing oversize material
• Compacts weathered rock, gravel, and coarse materials

d. Vibrating Roller

• Has mechanism that produces vibration while rolling
• Vibrations + static weight = efficient compaction
• Most effective for granular soils (sand and gravel)
• Available in single drum and tandem (double drum) varieties

e. Tamping Roller

• Similar to sheep foot roller but with larger and shorter feet
• Tamping effect compacts soil by kneading action
• Used for compacting silty-clay and clayey soils

f. Pneumatic Tired Roller

• Uses pneumatic rubber tires instead of steel drums
• Tires provide a kneading action
• Can compact both granular and cohesive soils
• Tire pressure adjustable for different soil types

g. Frog Rammer / Jumping Hammer

• Small mechanical compactor powered by an engine
• Operates by jumping up and down on soil
• Used for compaction in confined areas: trenches, around manholes, near walls

h. Plate Compactor

• Flat vibrating plate mounted over an engine
• Compacts soil by vibrating action
• Used for small areas and confined spaces
• Also used for compacting granular backfill around structures

Compaction Equipment Suitability by Soil Type 20812080

Selection Rule of Thumb: Cohesive soils (clay) → Sheepsfoot/Tamping Roller; Granular soils (sand/gravel) → Vibratory/Smooth Roller; Mixed soils → Pneumatic Tired Roller; Confined spaces → Frog Rammer/Plate Compactor.

4.3b Crushing Plants

• Crushing = process of reducing large rock pieces to smaller sizes suitable for construction

Types of crushers:

a. Jaw Crusher

• Has two jaws — one fixed and one movable
• Material fed from top, crushed by compression between jaws
• Used as primary crusher for breaking large rocks

b. Gyratory Crusher

• Has a conical head that gyrates inside a cone-shaped outer shell
• Material crushed by compression between head and shell
• Used as primary crusher for large capacity operations

c. Cone Crusher

• Similar to gyratory crusher but shorter
• Used as secondary crusher for producing smaller sized aggregates

d. Roll Crusher

• Two cylindrical rollers rotating in opposite directions
• Material fed between rollers, crushed by compression
• Used for soft to medium hard materials

e. Impact Crusher (Hammer Crusher)

• Uses impact force (hammers or blow bars) to break material
• Material fed into a chamber where rotating hammers break it
• Can produce more cubical shaped aggregates

Comparison of Crushing Equipment

Crushing process: Quarry blasting → Primary Crusher (Jaw/Gyratory) → Secondary Crusher (Cone/Roll) → Tertiary (Impact) → Screening → Stockpiling

4.4 Equipment for Concrete Construction 20792075207320712070

• Concrete = most widely used construction material
• Different equipment required for different stages of production and placement

a. Formwork / Shuttering

• Temporary structure to hold fresh concrete in desired shape until it sets
• Materials: timber, steel, aluminum, or plastic
• Steel formwork is more durable and reusable

b. Concrete Batching 2079 2071 2070

• Batching = measuring concrete mix ingredients (cement, sand, aggregate, water) by weight or volume
• Weight batching is more accurate and preferred for quality work
• Concrete batching plant automates this process for large projects

c. Concrete Mixing 2079 2075 2073 2071

• After batching, materials are mixed to produce a homogeneous mix

Types of concrete mixers:

i. Tilting Drum Mixer

• Drum-type mixer that tilts for discharging concrete
• Drum rotates about an inclined axis
• Easy to charge and discharge
• Common for small to medium projects

ii. Pan Mixer

• Circular pan with rotating blades that mix concrete
• Provides very uniform mixing
• Used for precast concrete and high-quality work

iii. Non-Tilting Mixer

• Drum rotates in a horizontal axis
• Concrete discharged by reversing drum or through a chute
• Used in batching plants

iv. Transit Mixer / Truck Mixer

• Truck with a rotating drum that mixes concrete while transporting
• Transports from batching plant to site
• Drum keeps rotating slowly to prevent segregation
• Capacity: 4–12 cubic meters of concrete

d. Concrete Transportation

Moving concrete from mixer to point of placement:

• Wheelbarrow: For small quantities over short distances
• Bucket Conveyor: Buckets on chains for vertical transport
• Chutes: Inclined troughs for gravity-fed transport
• Dumpers: Small vehicles for site transport
• Belt Conveyors: Continuous belt transport
• Concrete Pumps: Hydraulic pumps that push concrete through pipes to the point of placement. Can pump concrete to great heights and horizontal distances. Two types: line pump and boom pump

e. Concrete Compaction Equipment

i. Internal (Needle) Vibrators

• Also called needle vibrator
• Three parts: power unit, flexible tube, vibratory head
• Vibrating head introduced into fresh concrete to vibrate and consolidate
• Power: engine or electricity
• Vibrating needle = straight iron tube with eccentric weight inside

ii. Plate Vibrators

• Used to compact concrete with lesser thickness
• Surface vibrator used extensively in slab construction

iii. Vibrating Screed

• Surface vibrator capable of acting over large sections of concrete surface
• Used in finishing bridge decks and road pavements

iv. Form Vibrator

• External vibrators attached to concrete formwork
• Vibrate the form, which in turn vibrates the concrete
• Used in precast concrete production

v. Concrete Rollers

• Static rollers for compacting plum concrete or roller compacted concrete (RCC)
• Used for concrete with greater thickness
• Generally used in compaction of dams

f. Finishing Equipment

• After compaction, concrete surface finished by troweling, floating, or belts
• Hand trowels for smaller surfaces
• Power trowels for larger areas
• Power floats level concrete to accurate levels, powered by electric motors

Comparison of Concrete Mixers

Comparison of Concrete Vibrators

4.5 Cranes for Lifting 207620722070

• Hoisting = lifting load from one location, transporting, and landing it down
• Cranes are the most versatile and useful machine
• Only single machine providing 3D movements to a load in one continuous operation
• Operates with speed, safety, and precision
• Must know lifting capacity and working range before selection

Factors for Selecting Cranes 2072

1. Maximum load to be lifted: The crane must have sufficient lifting capacity (Safe Working Load, SWL) for the heaviest load.
2. Working radius required: The distance from the crane center to the farthest point of load placement.
3. Lifting height: The maximum height to which loads must be raised (e.g., number of stories in building).
4. Site conditions: Available space for crane erection, ground bearing capacity for foundation, accessibility, and obstructions.
5. Frequency of lifts: Number of lifts per hour/day — determines whether a high-capacity fixed crane or multiple mobile cranes are needed.
6. Type of load: Size, shape, weight distribution, and fragility of materials (precast elements, steel sections, formwork, concrete buckets).
7. Duration of use: Short-term use favors renting mobile cranes; long-term projects justify tower cranes.
8. Cost: Owning/rental cost, erection/dismantling cost, operating cost (fuel, operator), and transport cost.
9. Safety considerations: Proximity to power lines, wind conditions, and regulatory requirements.

Classification of Cranes 2076

Broadly cranes are classified into four categories:

a) Stationary / Derrick Crane

• Also called derrick crane
• Gives exceptionally large working radius
• Can be designed for any lifting capacity
• Power: steam, electric, or diesel-driven
• Applications: building construction, civil works, industrial erection, ports, shipyards, cargo handling
• Components: boom, bull wheel, and guy ropes

b) Overhead / Gantry Crane

• Used for handling materials over a rectangular area (factories, workshops)
• Moves in any direction and handles loads
• Hoisting mechanism mounted on carriage/crab traveling on a girder
• Girder moves longitudinally on rails on an overhead gantry

c) Mobile Crane

• Mounted on mobile chassis
• Truck cranes: high mobility
• Crawler cranes: slow but stable

Types of mobile cranes:

• Crawler crane
• Telescopic boom truck mounted cranes
• Lattice boom truck mounted cranes
• Rough terrain cranes
• All-terrain cranes
• Heavy lift cranes

d) Tower Crane

• Used in construction of industrial and multi-storeyed residential buildings
• Provides high lifting capacity and good working radius
• Takes up limited space around the worksite

• Generally fixed base type, mounted on a foundation
• Structural sections can be added to increase height
• Vertical limit called “maximum free standing” height
• Self-erecting tower to greater height is fairly easy and economical
• Self-erecting crane has hydraulically operated mechanisms below the slewing ring
• Also used in assembling high industrial plants and loading/unloading works

Principal components of tower crane:

• Undercarriage
• Slewing mechanism
• Slewing platform
• Tower with operator's cabin
• Hoisting and operating mechanism

Lifting System (Luffing System):

• System that constantly increases lifting capacity of a crawler crane
• Components: trailing counterweight, expendable counterweight, luffing system, luffing jib/derrick

Comparison of Cranes

Tower Crane vs Gantry Crane

4.6 Equipment for Tunnel Construction 207820762072207120702069

• Two methods of tunnel construction: conventional (drilling & blasting) and TBM

A. Conventional Method 2078 2070

• Excavation of tunnel by drilling and blasting = conventional method of tunnel construction

• Excavation by manual equipment is done for soft soil
• For rocks, drilling and blasting method is adopted
• The process of taking out excavated/blasted materials from the tunnel is known as mucking
• Mucking is done manually in wheelbarrows for small sections, whereas for larger diameter tunnels, loaders and railway wagons are used
• Excavated material is taken out as the tunnel progresses in depth
• Ventilation is needed when excavation is at sufficient depth. Arrangements are done through exhaust pipes — one pulls foul air from inside and another pushes fresh air inside
• Power is supplied to run equipment like exhaust fans, drilling machines, etc.

Equipment used in conventional tunnel construction:

• Excavators for soft ground
• Drilling machines
• Compressors to run drilling heads
• Earth transporting equipment for mucking excavated material
• Exhaust fans for ventilation
• Compressors to supply fresh air

B. Tunneling by Tunnel Boring Machine (TBM) 2078 2076 2070

• Modern tunnel constructions use TBMs
• Programmed head (moles) drills through mountain to bore tunnel
• Muck taken out through a pipe attached to boring machine

• Very fast and efficient method
• However, machines are very costly
• Length of tunnel must justify use — economical for longer tunnels
• Available in different capacities and diameters
• Can progress along fixed co-ordinates in X, Y, and Z directions

Advantages of TBM 20782076

1. Speed: Much faster than conventional drill & blast method — can advance 10-20 meters per day vs 2-5 m/day by D&B.
2. Continuous operation: Excavation, mucking, and lining can proceed simultaneously.
3. Safety: Reduced exposure of workers to hazards (rock falls, blast fumes). The shield protects workers.
4. Minimal ground disturbance: Reduces settlement and vibration impacts on surface structures.
5. Smooth tunnel profile: Produces circular profile requiring less concrete lining material.
6. Environmental: Less noise, vibration, and dust compared to blasting.
7. Automation: Can be programmed to follow precise coordinates (X, Y, Z) with laser guidance.

• Disadvantages: Very high capital cost, long mobilization time, difficult to transport, limited flexibility for varying cross-sections, not economical for short tunnels

Steps in Conventional Tunnel Construction (Drill & Blast) 2078

1. Setting out & survey: Establish tunnel alignment, grade, and cross-section using survey instruments.
2. Drilling: Drill holes into the rock face using jack hammers, pneumatic drills, or jumbo drills in a predetermined pattern.
3. Charging: Load explosives (dynamite, ANFO) into drilled holes. Insert detonators and connect wiring.
4. Blasting: Detonate charges in a controlled sequence. All personnel evacuated to safe distance before firing.
5. Ventilation: Allow blast fumes to clear. Run exhaust fans — one pulling foul air out, one pushing fresh air in.
6. Scaling: Remove loose rock from roof and walls to make the work area safe for the next cycle.
7. Mucking: Remove blasted rock debris using loaders, dumpers, or rail wagons. Muck is transported to disposal area.
8. Support installation: Install temporary support — rock bolts, shotcrete, steel ribs, or wire mesh (NATM approach).
9. Lining: Apply permanent concrete lining when sufficient length has been excavated.
10. Repeat cycle: Advance to next face and repeat the entire process (called the “advance per round”).

Comparison: Conventional (D&B) vs TBM

4.7 Equipment for Hydraulic Construction 2070

• Types of hydraulic construction: harbors, oil rigging, deep-sea structures
• Use special types of earthwork and concreting equipment

Equipment Used in Hydropower Construction

1. Excavators & Bulldozers: For excavation of dam foundation, canal, penstock trench, and powerhouse site.
2. Drilling & Blasting Equipment: Jack hammers, pneumatic drills for rock excavation in tunnels, surge shafts, and dam foundation.
3. TBM: For headrace and tailrace tunnels of medium to large hydropower projects.
4. Concrete Batching & Mixing Plant: Large-scale concrete production for dams, powerhouse, spillway.
5. Cranes (Tower & Gantry): For lifting heavy gates, turbine parts, generators, penstock sections.
6. Concrete Pumps: Pumping concrete to dam body, tunnel lining, and difficult-to-reach locations.
7. Dredgers: For underwater excavation, desilting of reservoirs and river beds.
8. Cofferdams & Dewatering Pumps: To create dry working area in river bed for foundation work.
9. Compaction Equipment: Sheep foot and vibratory rollers for earth/rockfill dam construction.
10. Conveyor Systems: Belt conveyors for transporting aggregate and concrete materials to dam site.

Comparison of Hydropower Construction Equipment

4.8 Equipment for Highway Construction 2073207120702069

• Highway construction involves earthwork in excavation, embankment construction, and pavement construction

a. Sub-grade Preparation and Compaction

• Subgrade prepared after earthwork in excavation
• Includes site clearance, grading, and compaction
• Grader used for uniform surface along cross section and longitudinal section
• Final compaction: sheep foot roller, tandem rollers, pneumatic tired rollers

b. Construction of Sub-base and Compaction

• Prepared after achieving finished subgrade surface
• Involves: quarrying materials, screening, transporting to site
• Spreading by loader or grader, compaction in layers
• Top surface graded with grader and final compaction done

c. Construction of Base Course

• Constructed similarly to sub-base construction
• Pavers or laying machines = important equipment for mixing, laying, and finishing

d. Equipment for Bituminous Pavement Work

i. Bitumen Boiler

• Used to heat bitumen to required temperature
• Modern boilers use diesel fuel burners
• Can be stationary or mobile

ii. Bitumen Distributor

• Truck that loads preheated bitumen from boilers
• Has burners fired by diesel/crude oil to control temperature
• Bitumen spraying bars spray bitumen in fan shapes through nozzles

iii. Aggregate Spreader

• Used for surface dressing work
• Spreads aggregates uniformly in a layer over sprayed bitumen
• Dump truck with spreading attachment on tail

iv. Asphalt Distributor

• Used to apply prime or tack coats on surface for paving preparation
• Available in truck mounted or trailer models
• Most important equipment on asphalt surface treatment project
• Components: insulated tank with heating system, spray bar, control system

v. Asphalt Concrete Plant

• Asphalt concrete = mix of bitumen binder + graded aggregates
• For patch work: batched and mixed manually
• For large jobs: done in batching and mixing plant (asphalt concrete plant)

vi. Concrete Pavers

• Also called paver finisher, asphalt laying machine, mat makers
• Self-propelled machine used for laying asphalt or concrete
• Normally fed by a dump truck

vii. Water Tanker

• Used for water supply and dust control during pavement construction

Comparison of Highway Construction Equipment

4.9 Selection of Construction Equipment 207920782074207320722069

• Equipment selection plays important role in execution of any construction project
• Proper selection contributes to timely, economical completion with desired quality

Two principal aspects of equipment selection:

1. Technical aspects — governed by performance
2. Economic and Commercial aspects — mainly concerning the contractor from a business sense

• After selection from technical point of view, test viability from economic/business point also

Planning for Equipment Selection

Involves working out answers to:

1. What is the equipment needed?
2. When is the equipment needed and for how long? (Duration of use)
3. How much equipment is needed? (Capacity assessment)
4. Which of the equipment is preferred based upon history of performance?

• At the onset, take concrete decisions on method to achieve target
• Utilize resources (Men, Machinery, Material & Money) in best possible way
• Done at pre-tender stage by studying contract documents, plans, and local conditions

Site Survey Factors

• Geological conditions
• Terrain conditions
• Availability of fuel
• Availability of labor
• Availability of services (electricity, water)
• Pollution standards

Careful Selection Considerations

1. Specifically designed for the purpose
2. Performance is fixed
3. The varying need
4. The combination may be needed
5. Match finding

Main Basis for Selection

Factors to consider when selecting construction plant:

• Identification of task
• Quantity of material
• Unit weight and size
• Changeable characteristics
• Haul distance
• Trafficability

Detailed Selection Factors

A. Task Considerations

• Nature of task and specifications
• Daily forecast of planned production
• Quantity of work and time allowed for completion
• Distribution of work at the site
• Interference expected and inter-dependence with other operations

B. Site Conditions

• Accessibility to location
• Maneuverability at the site
• Working space restrictions
• Altitude and weather conditions
• Working season and working hours
• Availability of local resources — manpower, materials, equipment
• Availability of land, power supply, and water supply for workshop and camp
• Availability of local equipment hiring, repair and maintenance facilities
• Availability of fuel, oil, and lubricants

C. Equipment Suitability

• Type of equipment considered suitable for the task
• Make, models, and sizes of special-purpose and general-purpose equipment
• Production capability, service conditions, and delivery time
• Equipment already owned by the contractor
• Usefulness for other and future tasks

D. Operating Reliability

• Manufacturer's reputation
• Equipment components — engine, transmission, brakes, steering, operator's cabin
• Use of standard components
• Warranties and guarantees
• Vendor after-sales service
• Operator's requirements, acceptability, adaptability and training
• Structural design
• Preventive maintenance program
• Safety features

E. Availability

• Availability of fuel, oil, and lubricants
• Maintenance and repair facilities
• Vendor after-sales service, repairs, spares and maintenance
• Availability of spare parts
• Standardization consideration

F. Economic Considerations

• Owning costs
• Operating costs
• Resale or residual value after use
• Replacement costs of existing equipment

G. Commercial Considerations

• Buy second-hand or new equipment
• Rent equipment
• Hire-purchase equipment
• Purchase or lease

• Equipment selection analysis leads to alternative choices for acquiring equipment
• Management decides on best option
• Final decision is usually a compromise between ideally required and what can be obtained economically

Factors for Deciding Extent of Mechanisation 2073

1. Volume and nature of work: Large-volume earthwork, concrete work, and repetitive tasks justify mechanisation. Small, scattered works do not.
2. Availability of labor: Where manual labor is scarce or expensive, mechanisation is essential. In labor-surplus areas, it may cause unemployment concerns.
3. Quality requirements: Machine-mixed concrete, machine-compacted earth, and machine-finished surfaces produce more uniform quality than manual work.
4. Time constraint: If project completion time is tight, mechanisation speeds up work significantly.
5. Site accessibility: Remote or difficult terrain may necessitate equipment, but narrow/confined spaces may prevent its use.
6. Cost comparison: Compare equipment cost (owning + operating + transport) vs manual labor cost for the same output.
7. Future utilization: If the equipment can be reused in future projects, purchase is more justified.
8. Environmental & safety: Hazardous work (demolition, deep excavation) favors mechanisation for worker safety.

Purchase vs Lease vs Hire-Purchase 2069

Decision Rule: If utilization > 60-70% of equipment life → Purchase. If utilization is short-term or sporadic → Lease/Rent. If capital is constrained but long-term use is expected → Hire-Purchase.

Important Things to Consider