Construction equipments

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CONSTRUCTION

EQUIPMENT

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CONSTRUCTION EQUIPMENT

Excavation

Equipment

Loading & Hauling

Equipment

Concrete

Equipment

Pumps

Compaction

Equipment

Construction

Robots

Lifting

Equipment

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EXCAVATION EQUIPMENTS

Dozers Excavators Scrapers Dragline and Clamshells Finishing Equipments

Bulldozers Angle Dozers Ripper

Shovel Backhoes Loaders

Graders Gradalls Trimmers

Crawler Wheel S/SU-type A-type U-type C-type

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DOZERS

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Bulldozer

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TRACTOR AND RELATED EQUIPMENT

• Tractors - Primary purpose to pull or push the loads

• Also used as mounts for many types of accessories :

– Front - end shovels

– Rippers

– Bulldozer blades

– Side booms (boom for lifting purposes)

– Hoes

– Trencher, etc.

• Two major types of Tractors:

• Crawler Mounted

• Wheel Mounted

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Crawler Mounted Bulldozer

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Wheel Mounted Bulldozer

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Angle Dozers

Landfill typeU-type

SU-typeS-type A-type

C-type

S-Straight blade - small size for cutting purposes Landfill type – for pushing for

pushing large quantity of material (ex. garbage)

SU-Semi Universal blade – combination of S and U type

A-Angle blade – blade which can be angled

U-Universal blade – for pushing large quantity of soil

C-Cushion blade – for pushing with a dozer

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• Bulldozers - Blades are mounted perpendicular to the direction of travel

• Angle dozer : Blades are set at an angle with the direction of travel

• Bulldozers pushes the earth in forward direction

• Angle dozers - push forward and to one side (ex. to fill trenches)

• Blade size indicated by its length and height

• Versatile machine -

– Clearing land of timber and stumps

– Opening up roads through mountain and rocky terrain

– Moving earth for haul distances upto approx. 100m

– Spreading earth fill

– Back filling trenches

– Maintaining haul roads

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1. ADVANTAGES OF CRAWLER MOUNTED BULLDOZERS:

1. Ability to deliver greater tractive effort

2. Ability to travel over muddy surfaces

3. Ability to operate in rocky formations,where rubber tires

might be severely damaged

4. Ability to travel over rough surfaces, which may reduce the

cost of maintaining the haul roads

5. Greater flotation (less sinking possibility) because of lower

pressures under tracks

6. Greater versatility on jobs

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2. ADVANTAGES OF WHEEL MOUNTED BULLDOZERS:

1. Higher travel speeds on the job or from one job to the

another

2. Elimination of hauling equipment to transport the bulldozer

to a job

3. Greater output, especially when considerable travelling is

necessary

4. Less operator fatigue

5. Ability to travel on paved highways without damaging the

surface

6. Adequate for earth moving on certain jobs. In general,

haul distance should be less than 100 m

7. During first passes, most initial earth will spill off the ends

of blade to form a windrow on each side of a lane

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Rippers

Single-shank Ripper Multi-shank Ripper

- all power concentrated in one ripper - power shared by the no. of rippers

- bigger boulders ripped out - smaller boulders ripped out

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EXCAVATORS

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Shovel

Hydraulic Rams

(Shipper Shaft)

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POWER SHOVELS

• Used predominately for hard digging above track level and loading haul units.

• Front dump and bottom dump bucketsBottom dump - More versatile

- Greater reach and dump clearance

- Easier to position for dumping

- Less spillage

However heavier than front-dump buckets.

• Limited ability to dig below the track level. Very efficient when digging from track level up to about the height of the shipper shaft.

• Capable of developing a high breakout force (the force applied to penetrate through the soil for excavation)

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POWER SHOVEL ……..contd.

• The vertical distance that permits the bucket to obtain a full load without undue crowding (full capacity) or hoisting is known as the optimum depth of cut.

• Varies with the shovel size and type of soil excavated.

• Use of optimum depth of cut will yield more production.

• Shovel must have a vertical face to dig against for effective digging.

• Digging face - easily formed when excavating a bank or hill side.

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Selecting A Power Shovel

Two primary factors are

• Cost per cubic meter of material excavated.( class of material,

operator skill, etc.)

• Job condition ( terrain, etc. )under which the shovel will operate.

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Power Shovel

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Backhoes

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BACKHOES

• Primarily used for excavation below grade.

• Digs by pulling the dipper (bucket) back toward the machine.

• Widely utilized for trenching work

• In addition to excavating the trench it can perform other trenching functions:

- Laying pipe bedding

- Placing pipe

- Pulling trench shields

- Back filling the trench

With the help of

different attachments

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Contd…

• For trenching best measure of production:

Length of trench excavated per unit of time

Dipper width should be chosen which matches the required trench width as closely as possible.

• Other suitable backhoe applications:

Excavating basements

Cleaning road side ditches

Grading embankments

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Backhoes

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Backhoe

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Loaders

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Differences between a Shovel and a Loader

Shovel:

• the boom, stick and the bucket comes as different parts attached to each

other from the machine

• it has more lifting height and greater swing

• the shovel sits in one place and does the excavation

• has smaller blades and more power

Loader:

• The boom, the bucket are directly attached to the machine for lifting the material

• it has lesser lifting height

• the loader after excavation travels some distances and unloads it

• has larger blades

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FRONT-END LOADERS

Used to

• Handle and transport bulk material such as rock and earth

• To load truck

• To excavate earth

• To charge aggregate bins of asphalt & concrete plants

• Two types :

– Crawler - Tractor - Mounted

– Wheel - Tractor – Mounted

• Classified by

– Capacities of buckets

– Weight that the buckets can lift

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Wheeled tractor loader

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Wheeled tractor loader

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Skid Steer Loaders – (miniature loaders)

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Backhoe cum Loader

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SCRAPERS

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Scraper

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SCRAPERS

• Designed to load, haul, and dump loose materials

• Greatest advantage – versatility

• Scraper types:

– Push-loaded

• Single-powered axle

• Tandem-powered axles

– Push-pull, tandem-powered axles

– Elevating

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Scraper

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Scraper

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DRAGLINE

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Dragline

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DRAGLINES

• Largest reach for digging and dumping of any member of crane-shovel family.

• Can dig to significant depths in soft to medium-hard material.

• Buckets available in a wide range of sizes and weights. Solid and perforated.

• While dragline is very versatile, does not have the positive digging action or lateral control of the shovel.

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DRAGLINES

More spillage must be expected in loading than a shovel.

Depends on skill of operator.

1.Dragline usually does not have to go into a pit or hole in order

to excavate.

2.Very advantageous when earth is removed from a ditch, canal

or pit containing water.

3.If earth hauled by trucks, they do not have to get into mud.

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OUTPUT OF DRAGLINES

The output will vary with the following factors:

• Class of material

• Depth of cut

• Angle of swing

• Size and type of bucket

• Length of boom

• Size of hauling units when used

• Skill of operator

• Physical condition of the machine

• Job conditions

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Dragline

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Dragline

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CLAMSHELL

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Clamshell

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CLAMSHELLS

• Clamshell has two main parts - Crane boom and clamshell bucket

• Used primarily for handling loose materials such as sand, gravel, crushed stone, coal, etc. and removing materials from cofferdams, pier foundations, sewer manholes, sheet-lined trenches etc.

• Especially suited for lifting materials from one location to another.

• Bucket penetration depends on bucket weight assisted by the bucket teeth.

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Clamshell Bucket Clamshell Bucket for long reach

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FINISHING EQUIPMENTS

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Graders

Moldboard/Blade

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GRADING & FINISHING

• Grading - Process of bringing the earthwork to the desired shape and elevation.

• Finishing (Finish grading) - Involves smoothing slopes, shaping ditches and bringing earthwork to the elevation required by the plans and specification

• Usually follows closely behind the excavation, compaction and grading.

• Equipment most widely used for finishing and grading - Grader

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GRADERS

• It can be used for light stripping, grading, finishing, back sloping, ditching, backfilling, and scarifying.

• Can be used in building construction projects as well as in heavy and higher construction.

• Blade may be pitched forward or backward.

Forward - results in rolling action of the excavated materials and is used for finishing work and blending materials.

Backward - increases cutting action but may allow material spill over top of the blade

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Grader

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Gradall

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GRADALLS

• A utility machine which combines the operating features of the backhoe, dragline and motor grader

• Versatile machine for both excavation and finishing work

• The bucket of a gradall can be rotated 90 degrees or more, allowing it to be effective in reaching restricted working areas and where special shaping of slopes is required

• Telescoping boom can be hydraulically extended or retracted to vary digging or shaping reach

• Can exert breakout force above and below ground level

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Gradall

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LOADING AND HAULING EQUIPMENTS

TRUCKS WAGONS

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Trucks

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Off-Way Carry Truck

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RIGID FRAME REAR DUMP TRUCK

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Wagons

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TRUCKS AND WAGONS

• Up to 100m - dozer or loader

100m - 1000m - scraper

>1000m - trucks

• Also conveyors or trays may be used if more

economical and large job.

• Heavy duty rear dump truck most widely used

• Most trucks may be operated over any haul road for

which the surface is sufficiently firm and smooth on

which the grades are not excessively steep.

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TRUCKS AND WAGONS

• Some units designated as off-highway trucks

because their size and total loads are larger

than permitted on highways. Used on large

highways projects where economically justified.

• Classified based on:

1. Size and type of engine

2. No of gears

3. Kind of drive-two wheel, four wheel, six wheel

etc.

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TRUCKS AND WAGONS …….contd.

4. No of wheels and axles and arrangement of

driving wheels.

5. Method of dumping load - rear dump, side

dump.

6. Class of material handled - earth, rock etc.

7. Capacity, in tons or m3-struck or heaped

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LIFTING EQUIPMENTS

CRANES JACKING SYSTEMS DERRICKS GANTRY HOISTS

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LIFTING EQUIPMENT

Need

1. Transport of material & people2. Installation of components

Classification

Lifting Equipment

Cranes Jacking System Derricks Gantry Hoists

Crane motions

• Travelling Hoisting (Lowering)

• Luffing ( Derricking) Slewing

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Crane Configurations

Tower Cranes Mobile cranes

Base type Boom type Mounting Boom type Out riggers Jib type counter weights

Static Travelling Luffing Horizontal Lattice boom Telescopic boom

boom boom

Fixed Luffing

Truck Crawler Rail

Crawler Truck All terrain Rough terrain Ringer

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Mobile Crane

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Mobile Crane

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LIFTING EQUIPMENT

Major factor controlling the load that may be safely lifted by a crane is its operating radius (horizontal distance from the center of rotation to the hook)

– for other than horizontal boom tower cranes, this is a function of boom length and boom angle.

– Other factors influencing a crane’s safe lifting capacity

• position of the boom in relation to the carrier

• whether or not out riggers are used (beams that wider the effective base of a crane)

• the amount of counter weight

• condition of the supporting surface

– safety regulations limit maximum crane load to a % of the tipping load

• tipping load - load that will cause the crane to actually begin to tip.

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Derrick Crane

74Derrick Crane

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Gantry Cranes

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Gantry Crane

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Gantry Crane

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Mobile Crane

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Mobile Crane

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Mobile Crane

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Tower Crane

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Tower Crane

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Tower Crane

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Tower Crane

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TOWER CRANES

– Tower cranes widely used on building construction projects because of its wide operating radius, and almost unlimited height capability.

– Majority of tower cranes are of the saddle-jib or horizontal boom type.

– Luffing jib (inclined boom) models are available which have the ability to operate in areas of restricted horizontal clearance not suitable for conventional tower cranes with their fixed jibs and counter weights.

– Different tower crane mounting possibilities.

– Climbing cranes are supported by completed building floors and are capable of raising themselves from floor to floor as building is erected.

– Most tower cranes can raise themselves section by section until the mast or tower reaches the desired height.

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INCLINED BOOM

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CONCRETE EQUIPMENT

CONCRETE MIXERS

BATCHING PLANT RMC(TRANSIT MIXERS)

CONCRETE PUMPS

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CONCRETE CONSTRUCTION

• Portland cement concrete most widely used structural material for civil engineering projects.

• Consists of portland cement, water, and aggregate

( Fine& Coarse )

• Cement, water and fine aggregate – mortar

• Normal concrete

– Three - Fourths aggregate

– One - Fourth paste by volume

• Admixtures added for specific purposes

– Entrain numerous microscopic air bubbles

– Impart colour

– Retard the initial set of the concrete

– Waterproof the concrete , etc.

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USUAL OPERATIONS INVOLVED IN THE PRODUCTION

OF CONCRETE

• Batching of

materials

• Mixing

• Transporting

• Placing

• Consolidating

• Finishing

• Curing

Aggregate

Cement

Water

Batching

Mixing

Handling and

transporting

Placing

FinishingCuring

Hoisting

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BATCHING AND MIXING OF CONCRETE MATERIALS

• Batching is weighing or volumetrically measuring and introducing into the mixer the ingredients for a batch of concrete

• A batch is the quantity of concrete mixed at one time

• Cement by volume: If sacked cement is used, the batches of concrete should be of such size that only full sacks are used. Unsatisfactory to divide sacks of cement on the basis of volume

• Cement by weight: On large projects cement may be supplied in bulk. Storage silos and weighing hoppers permit accurate measurement of cement and also permit full batch capacity of the mixer, an important items of cost reduction

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• Aggregate by volume: Unreliable except the most careful supervision, and should be permitted only as a last resort on unimportant work

• A small amount of moisture in the fine aggregate, which is nearly always present, causes the sand to bulk or fluff up.

• Fine sands bulk more than course sand for a given amount of moisture

• Therefore more accurate to measure the aggregate by weight.


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Aggregate by weight

• In most plants, weighing hoppers are suspended or placed under the storage bins. The material from the bin is fed by gravity

• Usually concrete specifications require the concrete to be batched with aggregate having at least two size ranges

(Coarse and fine) and upto six ranges.

• Single material batcher

• Multiple or cumulative batchers

– weighs different aggregates one at a time and loaded on top of those previously weighed

• Weigh beam scales

• Dial type scales

• Controls of batching equipment vary from fully manual to fully automatic


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• The concrete should be mixed thoroughly until it is uniform in appearance, with all ingredients evenly distributed.

• Mixers should not be overloaded and should be operated at the speeds for which they are designed

• If the blades become worn or coated with hardened concrete, the mixing action will be less efficient

• If adequately mixed samples from different portions of a batch will haul essentially the same unit weight, air content, slump and coarse aggregate content

• Two types of concrete - mixing operations in use,

– Job - batched concrete - 99 % in India

– Central batched concrete - Most concrete in western countries


9595

• Often mixed at the job site in a stationary mixer

• Stationary mixers

– On site mixers

– Central mixers in ready mix plants

– Tilting or nontilting type

• Specifications usually require min. of one minute mixing for

stationary mixers of upto 1 m3 with an increase of 15 seconds

for each additional 1 m3 capacity.

• Upto about 10% of the mixing water should be placed in the

drum before the solid material is added.

• Water should then be added uniformly with the solid material,

leaving about 10% to be added after another material are in the

drum


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• As per IS 4925 : 1968 - specification for concrete batching and

mixing

Capacity of mixer ( m3) Time for Mixing ( minutes)

Upto 2

Upto 3

Upto 4

One and half

Two

Two and half

• Mixing time after all materials except the full amount of water, are in mixer, provided that all the mixing water shall be introduced before one fourth of the mixing time has elapsed. (Based on standard speed of rotations)

• Maximum capacity of the plant - Based on minimum mixing cycle time


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• Mixers are specified by the volume of mixed concrete

discharged after mixing of each batch, expressed in m3 or ft3

• Some times the total volume of the unmixed ingredients is given

as a prefix.Thus, a total 10/7 mixer takes 10 cu.ft. of unmixed

material and gives 7 cu.ft. of mixed concrete per batch

• The mixer drum speed is usually 18 to 20 r.p.m.


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10/7 Concrete Mixer

Non Tilting Concrete MixerPan Mixer

Hand Feed Concrete Mixer

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CONCRETE MIXER

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CONCRETE MIXER

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BATCHING PLANT

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BATCHING PLANT

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BATCHING PLANT

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BATCHING PLANT

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READY MIXED CONCRETE

• Can be manufactured by any of the following method of mixing

– Central - mixed concrete is mixed completely in a stationary mixer and is delivered either in a truck agitator, a truck mixing operating at agitating speed

– Shrink - mixed concrete is mixed partially in a stationary mixer and completed in a truck mixer

– Truck - mixed concrete is mixed completely in a truck mixer

• 70 to 100 revolutions of the drum or blades at the rate of rotation specified by the manufacturer, required to produce the specified uniformity of concrete.

• Not more than 100 revolutions at mixing speed are allowed. After 100 should be done at a rate designed for agitation

• Agitating speed is usually 2 to 6 rpm, while mixing speed is generally about 6 to 18 rpm

• Concrete should be delivered with in one and half an hour or before the drum has revolved 300 times

106RMC

107RMC

108HELICAL BLADES INSIDE RMC

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RMC

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RMC

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Concrete Pump

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Concrete Boom Pump

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Concrete Boom Pump

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COMPACTION EQUIPMENT

TAMPING ROLLERS

SMOOTH-WHEELEDROLLERS

VIBRATING ROLLERS

PNUEMATIC TYRED ROLLERS

VIBRATORY COMPACTORS

ROLLERS COMPACTORS

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TYPES OF COMPACTING EQUIPMENT

-Tamping rollers

-Smooth-wheel rollers

-Pneumatic-tyred rollers

-Vibrating rollers - including the three above

-Self-propelled vibrating plates and/or shoe

-Manually propelled vibrating plates

-Manually propelled compactors

- Vibratory compactors for deep sand

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TAMPING ROLLERS

• Of sheep foot type or modifications

• May be towed or self-propelled

• Hollow steel drum on whose surface a no. of projective steel feet are welded

A unit may consist of one or more drums mounted on more and more axles.

The weight of a drum may be varied by adding water or sand.

Feet penetrate the soil to produce a kneading action and a pressure to mix and compact the soil from the bottom to the top of the layer.

120

TAMPING ROLLERS

• With repeated passage the penetration decreases, until the roller is

said to walk out of the fill.

• Effective in compacting clays and mixtures of sand and clay

• Can’t compact granular soils

• Depth of compaction limited to approx length of feet

• Modified tamping rollers - grid rollers

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Tractor Pulled Ballasted Grid RollerTamping Roller

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SMOOTH WHEELED ROLLERS

• May be classified by weight, in tons or kgs

• Some rollers may be ballasted with water or sand to increase the weight

• If designated 8-12 tons, minimum weight 8 tons and maximum weight 12 tons

• Specs may be of two types– designation by weight

– designation by weight per cm of roll (40 kg/cm)

• Specifying weight only does not mean necessarily indicate the compressive pressure

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SMOOTH WHEELED ROLLERS

• In cohesive soils, these rollers tend to form a

crust over the surface which may prevent

adequate compaction in lower portions of the

layer.

• Effective in compacting granular soils

• Also effective in smoothing surfaces of soils that

have been compacted by tamping rollers.

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Smooth Wheeled Rollers

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Smooth Wheeled Rollers

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Pneumatic Tyred Rollers

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PNEUMATIC-TYRED ROLLERS

• Large-tyred rollers utilise two or more big earth-moving tyres on a single axle

• Sizes may vary from 15 to 200 tons gross weight and tyres air pressure may vary from 80 to 150 psi (5.5 to 10.5 kg/cm2 or 550 to 1050 Kpa)

• Because of the heavy loads and high tyre pressures, they are capable of compacting all types of soils to greater depths.

• Four methods of indicating the compacting ability of pneumatic rollers

– the gross weight of the unit

– the gross weight per wheel

– the weight per inch of tyre width

– the air pressure in the tyres

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PNEUMATIC-TYRED ROLLERS

• Since the area of contact between the tyre and

ground surface over which it passes varies with

the air pressure in the tyre, the first 2 methods

are unsatisfactory

• Therefore should specify

– The gross weight

– No. and sizes of tyres

– Tyre inflation pressure

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Pneumatic Tyred Roller

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Pneumatic Roller

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Pneumatic Roller

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Pneumatic Roller

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VIBRATING COMPACTORS

• Sand, gravel and large stones respond well to compaction produced by a combination of pressure and vibration

• On vibration the particles settle to increase density of the mass

• Vibrations may vary from 1,000 to 5,000 per minute

• Slow speeds permit a greater flow of vibratory energy into the soil

• Better compaction efficiencies and economy are attained by moving at slow speeds - 2.5 to 4 Kmph

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Vibratory Rollers

Smooth Drum Vibratory soil compactor Padded Drum Vibratory soil compactor

135

MANUALLY OPERATED VIBRATORY PLATE

COMPACTORS

• In locations where large units are not practical

• Self propelled for consolidating soils and asphalt

• Rated by

– centrifugal force

– exciter revolutions per min.

– Lift

– feet per minute travel

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Diesel Powered Manually operated Plate

Compactors

137

MANUALLY OPERATED VIBRATING TAMPING

COMPACTOR

• Where large units are not practical

MANUALLY OPERATED RAMMER COMPACTOR

• For compacting cohesive or mixed soils

• Impact rates up to 850 per minutes

• Self - propelled in that each blow moves than ahead slightly to

contact new soils

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Manually Operated rammersThe equipment performing in

a congested trench

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PUMPS

JET PUMPS

SUBMERSIBLE

DISPLACEMENT TYPE

RECIPROCATING DIAPHRAGM SELF-PRIMING

CENTRIFUGAL TYPE

MULTI-STAGE

140

PUMPS IN CONSTRUCTION PROJECTS

• Pumps are used extensively in the construction

projects for:

– Removing water from the pits, tunnels, etc.

– Lower the water table for the excavation

– Dewatering the cofferdams

– Furnishing water for the jetting and sluicing

– Furnishing water for many types of utility services

– Foundation grouting

• On some projects may be the most critical equipment

141

Dewatering Pumps

142

Dewatering Pumps

143

Dewatering Pumps

144

• Factors to be considered in selecting type of pump:– Dependability

– Availability of parts

– Simplicity to permit repairs

– Economical installation and operation

• Issues involved in selection– Lift

– Head

– Type of fluid

– Power Source

– Size of pump’s discharge connection

– Pump’s rated power

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CLASSIFICATION OF PUMPS

• DISPLACEMENT PUMPS

– Diaphragm pumps

– Reciprocating pumps

• CENTRIFUGAL PUMPS

– Self - priming pumps

– Submersible pumps

– Multi-stage pumps

146

RECIPROCATING PUMPS

• Operates as the result of movement of a piston inside a cylinder

• The piston may move the water only when it is moving in one direction - single acting

• Double acting - Water is taken in when piston is moving in both the direction - by appropriate additional valves

• Pumps can contain more than one cylinder mounted side by side

– Two cylinders - duplex

– Three cylinders - triplex

– one cylinder – simplex

Duplex double-acting, Duplex single acting etc.

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Reciprocating Pumps

• The capacity of a reciprocating pump depends essentially on the speed of the pump and is independent of the head

• Water delivered with pulsation

Advantages:

1. They are able to pump at a uniform rate against the varying head

2. Capacity increased by increasing the speeds

3. Reasonably high efficiency regardless of the head and speed

4. Usually self – priming

Disadvantages:

1. Heavy weight and large size for given capacity

2. Possibility of value trouble, especially in pumping water containing trash

3. Pulsating flow of water

4. Danger in damaging a pump in operating against a high head

148

Reciprocating Pump Diaphragm Pump

149

Diaphragm Pumps

• The central portion of the flexible diaphragm is alternatively raised and lowered by the pump rod

• This action draws water into and discharges it from the pump

• Best suited for

– Dewatering jobs where the liquid contains a high proportion of trash, mud, sand

– Handling variable seepage of water as in trench work

– Pumping the combination of water and air from a small well -point system

150

151

Centrifugal Pumps

• Contains an impeller, rotation element, which impacts velocity to the water passing through the pumps

• The kinetic energy imparted to a particle of water as it passes through the impeller is sufficient to cause the particles to rise to some determinable height

• If a drop of water is allowed to fall freely, it will strike the surface with a velocity

V = (2gh) ½

• If the fall is 10 m, the velocity will be 14 m/sec

152

Centrifugal Pumps

• if the same drop is given an upward velocity of 14 m/sec it will rise 10 m assuming no loss in energy due to friction through air

h = v2 / 2g

the potential head will be four times as great if the velocity head is doubled

• Power required to operate a centrifugal pump is as given earlier

– efficiency may be as high as 75%

153

154Self priming centrifugal pump a) Priming action b)Pumping action

155

SELF PRIMING CENTRIFUGAL PUMPS

• On most construction projects pumps must be frequently set up above the surface of water to be pumped

• Self-priming pumps avoid the problem of repriming every time used

• They use recirculation method

– Water reservoir contained with in the pumps. As the impeller rotates, it draws water from the reservoir and air from the suction line

– Since they don’t mix and the air is discharged and water recirculated to pick up more from suction line. Continues till water flows through pipe

– Trap valve - to keep reservoir filled

156

SUBMERSIBLE PUMPS

• Powered by a water proof electric motor in the common housing

with the pump to operate submerged in water.

• Handles water practically in the same manner as centrifugal

pumps

• Advantages

– Eliminates suction lift limitations

– loss of prime

– Need for suction hoses

– Noise and fumes from an internal combustion engine

157

Submersible Pumps

158Electric motor operated submersible pump Submersible pump placed in position

159

MULTISTAGE CENTRIFUGAL PUMP

• Means of increasing the performance to develop a higher head or

greater pressure with the use of multi-stage centrifugal pump

– It has two or more impellers where the discharge from one

impeller flows into the suction of another

– Each stage increases the velocity or pressure head of the fluid

– Particularly suitable for water jetting or sluicing work

160Single stage Centrifugal Pump Multi-stage Centrifugal Pump

161

Jet Pumps

• Recirculate portion of the pump output to a venturi tube located below the source water level and then back to the pump inlet.

• Low pressure in the venturi tube draws water from the source into the recirculating line, where it flows into the pump inlet.

• While relatively inefficient, capable of lifting water upto 30m or more.

• Other advantages

– Simplicity

– ease of maintenance

– Ability to operate in wells having diameter as small as 2 inches

– Ability to locate the pumps on the surface

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Jet Pumps

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CONSTRUCTION ROBOTS

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165

166FLOOR FINISHING ROBOT

167MATERIAL HANDLING ROBOT

168

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• This is the largest earth mover in the world..... built by the German company, Krupp, and seen here crossing a federal highway in Germany en route to its destination (an open-pit coal mine). It is cheaper to move the thing like this, than to construct or reassemble onsite.

• Specifications:~ The mover stands 311 feet tall and 705 feet long.~ It weighs over 45,500 tons~Cost $100 million to build~ Took 5 years to design and manufacture~ 5 years to assemble.~ Requires 5 people to operate it.~The Bucket Wheel is over 70 feet in diameter with 20 buckets,each of which can hold over 530 cubic feet of material.~ A 6-foot man can stand up inside one of the buckets.~ It moves on 12 crawlers (each is 12 feet wide, 8' high and 46 feet long). There are 8 crawlers in front and 4 in back. It has a maximum speed of 1 mile in 3 hours (1/3 mile/hour).~It can remove over 76,455 cubic meters each day.(100,000 large dump trucks at 40yds. each)

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• The Emmaus Church in

Heuersdorf, a small town in

eastern Germany near Leipzig,

must be moved in order to

save it. The entire town is

being abandoned as a nearby

lignite, or brown coal, mine

expands.

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• A huge excavator sits at the bottom of the lignite mine, with the 13th-century church looming in the background. The estimated 52 million tons of lignite beneath the town will go to a nearby power station in Lippendorf.

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The town won a legal battle to prevent the takeover from the mining

company, but the decision was overturned in 2005. This photo shows the

early stages of preparing the church to move. The area surrounding the

church was cleared and cracks within the building's structure were

repaired with concrete.

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• Engineers then wrapped the

church in four steel corsets

and painstakingly put a

steel-and-concrete base

under the church.

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Emmaus Church's pastor Thomas Krieger had a hard time

finding it a new home and even considered putting it on the

side of a highway. It will soon be located in the nearby town

of Borna, right next to one of that town's churches. "It's not

the ideal location, for sure, but it's the best we got," Krieger

told the newspaper Die Welt.

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The church was lifted 1.6 meters using hydraulic lifts to make

room to move in an enormous, multi-wheeled transport bed.

Additional preparations for the €3 million move included

repairing roads, diverting small rivers and taking down power,

phone and traffic lines.

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The 12 km (7.5 mile) trip will go at a walking pace and is

expected to end on Oct. 31. Structural engineers will

accompany it the whole way, using sensors to make sure

the church doesn't lean more than three degrees. The

town's roughly 50 inhabitants have until Dec. 31, 2008, to

abandon their homes.

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At least this church is safe: Heuersdorf's second, larger

church will meet the wrecking ball next year.

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THANK YOU

Education

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