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.

Final Design

Gantry Crane Design

Above is a drawing of the final design. The design is based on a workshop gantry crane and it is very simple in design as this was done deliberately to minimise the effort and confusion when setting up the crane and when using it. Therefore the crane comes only in three pieces one I beam and two struts.
I decided that a mechanical winch and a mechanical hoist would be the best option again to make things easier for the user. The winch will slide into the I-beam whilst setting up it will have wheels which will move the crane in the X direction. A diagram of the winch on the I-beam can be seen below:

The I-beam will be bolted onto the I-beam via 8 bolts these will be sufficient enough to hold the parts together. These will be the only parts on the crane that will be bolted together.
See below:

The crane will rest on rubber spheres that are flat at the bottom; it will be placed on rough ground so the spheres will fit into the ground to provide extra stability. Initially we thought about adding wheels but these would have been unnecessary and may have reduced the stability of the crane. The design of the crane is actually quite durable, there are no wheels or no attached bits to the crane therefore one does not have to worry about things breaking.

The crane parts can easily be transported by a small helicopter and taken to the site. It will take a total of 8 people to carry the crane parts; 3 people for the beam two people for each strut and one person to carry the winch and hoist. Although the beam itself will not be able to fit inside a land rover a separate carrier compartment can be made where the crane can be hauled by the 4X4.

Below are drawings illustrating the dimensions of the crane:
















(Supporting Sphere)













I-Beam (The I-beam will be 5M in length)





















(Strut Side View)











Square beam (struts) this is a cross section of the struts.

(support and bolting plate) this is where the struts bolt onto the I-Beam. The triangle piece is there to provide support to the beam.

Initial Beam Design