Mechanical Engineering Technology

Mechanical Engineering

Introducation

• It is a common fact that we find a wide variety of construction machines on every construction sites, which make the construction jobs easy, safe and quicker.

• Depending on the application, construction machines are classified into various categories which we are discussing here.

• Earthmoving equipments

• Construction vehicles

• Material handling equipments

• Construction equipments

Group A : Earthmoving Equipments

A1 : Excavators

• Excavators are heavy construction equipment consisting of a boom, stick, bucket and cab on a rotating platform (known as the "house").

• The house sits atop an undercarriage with tracks or wheels.

• Excavators are also called diggers

• Excavators are used in many ways

• Digging of trenches, holes, foundations

• Material handling

• Brush cutting with hydraulic attachments

• Forestry work

• Demolition

• General grading/landscaping

• Heavy lift, e.g. lifting and placing of pipes

• Mining, especially, but not only open-pit mining

• River dredging

Bucket Wheel Excuavator

Shovels

Dragline

Cable Excuavator

A2 : Loaders

• A loader is a heavy equipment machine often used in construction, primarily used to Load material (such as asphalt, demolition debris, dirt, snow, feed, gravel, logs, raw minerals, recycled material, rock, sand, and woodchips) into or onto another type of machinery (such as a dump truck, conveyor belt, feedhopper, or railcar).

A2 : Skin Steer Loaders

• A skid loader or skid-steer loader is a small rigid frame, engine-powered machine with lift arms used to attach a wide variety of labor-saving tools or attachments.

• Though sometimes they are equipped with tracks, skidsteer loaders are typically fourwheel vehicles with the wheels mechanically locked in synchronization on each side, and the left-side drive wheels can be driven independently of the right-side drive wheels.

Group B: Construction Vehicles

B1 : Dumpers

• A dumper is a vehicle designed for carrying bulk material, often on building sites. Dumpers are distinguished from dump trucks by configuration: a dumper is usually an open 4-wheeled vehicle with the load skip in front of the driver, while a dump truck has its cab in front of the load.

• The skip can tip to dump the load; this is where the name "dumper" comes from. They are normally diesel powered. A towing eye is fitted for secondary use as a site tractor. Modern dumpers have payloads of up to 10 tones and usually steer by articulating at the middle of the chassis.

B2 : Tippers

• A truck or lorry the rear platform of which can be raised at the front end to enable the load to be discharged by gravity also called tip truck.

• Tippers are suited for the rough and tumble of mining & quarrying operations, as well as for carrying bulk loads in construction and infrastructure industries. Complete maneuverability, high performance and longterm endurance are common to all trucks, resulting in lower operating costs.

• A trailer is generally an unpowered vehicle pulled by a powered vehicle.

• Commonly, the term trailer refers to such vehicles used for transport of goods and materials.

Group C: Material Handling Equipments

C1 : Cranes

• A crane is a type of machine, generally equipped with a hoist, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It is mainly used for lifting heavy things and transporting them to other places.

• It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of a man. Cranes are commonly employed in the transport industry for the loading and unloading of freight, in the construction industry for the movement of materials and in the manufacturing industry for the assembling of heavy equipment.

C1 : Conveyors

• A conveyor system is a common piece of mechanical handling equipment that moves materials from one location to another. Conveyors are especially useful in applications involving the transportation of heavy or bulky materials. Conveyor systems allow quick and efficient transportation for a wide variety of materials, which make them very popular in the material handling and packaging industries.

Group D: Construction Equipments

D1: Tunnelink and Handlink Equipments

• A tunnel boring machine (TBM) also known as a "mole", is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They can bore through anything from hard rock to sand. Tunnel diameters can range from a meter (done with micro-TBMs) to 19.25 m to date. Tunnels of less than a meter or so in diameter are typically done using trenchless construction methods or horizontal directional drilling rather than TBMs

D2: Concrete Mixers

• A concrete mixer (also commonly called a cement mixer) is a device that homogeneously combines cement, aggregate such as sand or gravel, and water to form concrete. A typical concrete mixer uses a revolving drum to mix the components. For smaller volume works portable concrete mixers are often used so that the concrete can be made at the construction site, giving the workers ample time to use the concrete before it hardens.

Precautions

• Repairs

• Never repair any diesel or air equipment while it is in operation or under pressure.

• Power lines

• Make sure that machines or equipment do not come too close to electric power lines. The machine does not actually have to contact a power line for the machine to be energized.

• Hammer and driving heads

• When a pile driver is not in use, use a cleat or timber to hold the hammer in place at the bottom of the leads. Secure the driving heads when using the rig to shift cribbing or other material. Never place your head or other parts of your body under suspended hammers that are not dogged or blocked in the leads.

• Drums, brakes, and leads

• Keep hoisting drums and brakes in the best condition possible and shelter them from the weather. Keep leads well greased to provide smooth hammer travel.