Lifting Chain

Lifting chain is designed for use with hoists, cranes, winches, and other material handling equipment. It is also used in rigging slings and for lashing. There are two standard grades for lifting chain: grade 80 lifting chain and grade 100 lifting chain
We will be using grade 100 lifting chain which is made of alloyed steel and is hardened and tempered for superior durability and fatigue resistance.Grade 100 lifting chain is made of Herc-Alloy 800, a heat-treated alloy with very high strength. 'When working with lifting chain, working load limit and rated capacity vary with the angle of use and the number of lifting chain used in a sling. For example, a single 5.5 mm lifting chain may be rated for 2100 lbs. at 90 degrees. A double 5.5 mm lifting chain may be rated for 60, 45, or 30 degree use with working loads of 3600, 3000, and 2100 lbs. respectively.'

Nuts and Bolts

The nuts and bolts which we will use in the manufacturing of our crane will be made of stainless steel. The nuts as well as the bolts will be coated with zinc to prevent corrosion.Stainless steel is a type of metal alloy. The components of stainless steel are iron, chromium, carbon, nickel, molybdenum and small quantities of other metals. These components are present in varied proportion in different varieties of steels. In stainless steel, the chromium content should not be less than 11 percent. The high content of chromium present in stainless steel is responsible for corrosion resistant property. In order to achieve higher resistance to corrosion nickel is added. Iron is the primary component of steel but it resists oxidation because the chromium present in the steel reacts with oxygen to form chromium oxide. It adheres to the surface of the stainless steel in the form of a tough, passive coating. In case the surface of this layer is damaged due to some chemical or mechanical effect, the chromium oxide formed, is capable of mending the damage. The strength and toughness of steel is because of the carbon present in it. With the increase in the carbon content the toughness of steel also increases

Reasons For Using HSLA Steel

Reason for Using HSLA

:HSLA steels contain additions such as zirconium, calcium, or rare-earth elements for sulfide-inclusion shape control.

: Additions of elements such as copper, silicon, nickel, chromium, and phosphorus can improve atmospheric corrosion resistance of these alloys

: Grades known as "improved-formability" HSLA steels (sheet-steel grades designated ASTM A715, and plates designated ASTM A656) have yield strengths up to 80,000 psi, yet cost only about 24% more than a typical 34,000-psi plain-carbon steel

: High-strength low-alloy (HSLA) steel is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel

: HSLA steels are usually 20 to 30% lighter than a carbon steel with the same strength.

: HSLA steels are also more resistant to rust than most carbon steels, due to their lack of pearlite – the fine layers of ferrite (almost pure iron) and cementite in pearlite

Final Material Used

Final Material

We will be using HSLA(High Strength low-alloy Steel) to manufacture our crane. It provides better mechanical properties or more resistance to corrosion as compared to carbon steel. HSLA steels vary from other steels as they are made to meet a specific mechanical property and not to a specific chemical property. It has small amount of alloying elements like copper,nickel , nitrogen, vanadium, chromium, molybdenum, titanium, calcium, rare earth elements . These elements are intended to alter the microstructure of carbon steels, which is usually a ferrite-pearlite aggregate, to produce a very fine dispersion of alloycarbides in an almost pure ferrite matrix. This eliminates the toughness-reducing effect of a pearlitic volume fraction, yet maintains and increases the material's strength by refining the grain size, which in the case of ferrite increases yield strength by 50% for every halving of the mean grain diameter. The yield strength of HSLA steel lies between 250-590 megapascal. HSLA steels require around 30% more power to form as compared to carbon steels because of its great strength.
To increase corrosion resistance elements like Copper, silicon, chromium, nickel and phosphorus are added. Increased formability is needed because HSLA steels have directionally sensitive properties. Impact Strength and formability vary significantly when tested transversely and longitudinally to the grain. HSLA steels when treated for sulphide shape control have directional characteristic reduced substantially.
HSLA steels are lighter as compared to carbon steel with same strength and due to fine layer of ferrite (almost pure iron) and cementite in pearlite HSLA steels are more resistant to rust than most carbon steel

Raw Materials Required

Raw Materials:

The most important material used to manufacture cranes is steel, which is an alloy of iron mixed with small amount of carbon to increase its hardness. Carbon steel is used for structures that do not require very high strength. The most important factor which determines the property of carbon is the amount of carbon present in it, which may range from 0.015% to more than 0.5%
HSLA steels are used for the manufacturing of cranes that are designed to lift very heavy objects. HSLA steel contains low levels of carbon and small amount of other elements such chromium, nickel, vanadium, titanium and niobium. Hsla steels resist atmospheric corrosion and are better suited to welding than carbon steel
Wide varieties of other materials are also used in the manufacturing of cranes. Natural or Synthetic rubbers are used to make tires for cranes which are mobile. Electrical components may include semiconductors such as germanium and silicon and copper wires for electrical circuits.

Initial Designs

These designs were sketched and was given to our chief designer for final selection.I had come up with these ideas before the vacation and had given them to Varinder and Richard for better understanding .

What is a Crane

A crane can be described as a machine which is capable of lowering and lifting heavy objects and also moving them horizontally the difference between a crane and hoist is that hoist can lift objects vertically but cant move them horizontally. The word crane is taken from the fact that these machines have a shape similar to that of the tall, long-necked bird of the same name.
As early as the first century, cranes were built which were powered by animals or human beings .these types of cranes had a boom connected to a rotating base. It had a treadmill which powered the drum around the rope was wounded. The rope was attached to the pully at the top of the boom and to a hook or holder which lifts the load or weight.
A great advancement was made in crane design during Middle Ages when an horizontal arm called the ‘jib’was attached to the boom in a way which allowed it to pivot, allowing for an increased range of motion
Cranes continued to be operated by human being until middle of the 19th century when steam engines were developed. Electric motors and internal combustion engines were used to power cranes . During the first half of twenth century cranes were developed is such a way that it had tall slender towers with the boom and the operator on the top of the tower. During the 1950s, the availability of stronger steels, combined with an increased demand for taller buildings, led to the development of cranes with very long booms attached to small trucks, or to crawlers with caterpillar treads. Mobile cranes and tower cranes of many different kinds are used extensively in construction sites around the world.