Guess, what is the first thought when it comes to Civil Engineering? Yes, it is “Structures”, the spotlight of Colossus. The basis of a good structure lies in the mix of innovation, analysis, and the determination to create an identity. This edition of ENGINEER offers a hands-on experience in building a Tower crane using aluminium sections. Such a lifting machine is used very commonly to transport steel bars, concrete, tools and other building materials especially in high rise construction sites.

The Participants are required to analyze, design and fabricate a model of a tower crane of specified dimensions, using Aluminium L-sections and other specified materials that can sustain the design load under permissible deflection for minimum cost incurred.
Specifications
A tower crane has the following parts: a horizontal jib (jib and a counter jib) or the boom and a vertical mast (figure 1). Following are the specifications of the tower crane:

• The tower mast should have four columns made of L sections.
• The boom and tower mast joint should be such that the boom can rotate in the horizontal plane.
• The tower mast should be trussed with a maximum section dimension of 8*8 sq cm.
• The boom should also be trussed with a maximum sectional area of 5*5 sq cm. Sections can be triangular, rectangular or square.
• Length of the loading jib should be greater or equal to 100 cm with a maximum allowable length of 120 cm. The counter jib should not be longer than 60 cm (figure 2).
• Maximum height of the structure is 120 cm and the boom should be at least 80 cm from the ground level.
• One loading point is at the end of the lifting jib and the location of the other is variable. The counter weight will be placed at the end of the counter jib.
• Additional cables can be used to support the jibs.
• Participants will be provided with steel plates, as a base for the tower mast. Steel plates may be used for other parts in the crane too, as the participant feels appropriate

Figure 1

Figure 2

The event has three stages:
Stage I Teams are expected to send their design and tender document in MS-word document, AutoCAD drawings etc, through email. Teams will be shortlisted based on these documents. Preference will be given to the team with innovative and economical design.

Stage II Shortlisted teams will be invited to the Engineer'11 and are required to give a power point presentation explaining their design methodology, analysis, and economics. The teams should justify why their design is unique. Judges would prefer to see the design analysis of the structures done using STAADPro or SAP during the presentation.

Stage III After the presentation, participants can build their structure according to their respective designs, using the materials and tools supplied by the organizers. After completion of construction, the structure will be tested in the presence of the team.

Last date for submission of design and tender is 15th October 2011

Details Expected in Tender

• Analysis and design of the structure in word document.
• Amount of materials required and the total cost of the materials. The tender should also give the total number of man hours required to complete the construction in terms of cost and time in word document. (For material details, see below).
• Plan and elevation of the structure in AutoCAD drawing format or any 2D or 3D rendering.

The proposals shall be evaluated based on the following criteria:
P = (W.H.L)/(C.A)
Where,
P = points
W= load carried by the structure without failure
H= height of tower mast
L= length of the jib
C= cost of the structure (in units)
A= area of the base

Note:

• All units according to S.I system
• Points are also allotted for the innovative designs and presentation.
• Extra materials or extra man hours may be provided upon request if felt necessary and appropriate by the organizers, during the construction stage at double the normal cost.

Materials Provided

• Aluminum L-sections of dimensions 1 inch x 1 inch and 0.5 mm thickness and 3.6 m in length (Wastages due to non compatibility of lengths have to be calculated and additional material required to be quoted appropriately).
• Nuts and bolts for the joints.
• Hacksaw blades and frame, spanner and power drill will be provided. Any other material as required by the participant will be provided, if felt necessary and appropriate by the organizers.
• Participants can now use the following sections for your design
  1. L section, width - 0.5 inch, thickness - 1mm
  2. L section, width - 0.75 inch, thickness - 1mm
  It is recommended that the designs be done using these sections.

Cost of materials (C)

• L-sections - 35 units/m
• Nuts and bolts - 2 units each
• Labour - 20 units/ man hour. (1 man hour = 1 man working for 1 hour, 3 people working for one hour = 3 man hours).
• Steel plate-0.2units/cm.sq

Loading Criteria:

• The structure will be bolted to the fixed plate by bolting it through the base plate.
• Counter weights will be placed first and the structure should be able to remain stable even after loading.
• The counter jib will be then loaded with the fixed and the variable load placed simultaneously.
• The loads will be successively increased until failure, and the values noted down

Criteria for failure

• Toppling
• Failure of joints or members
• Any undue deformation or deflection more than 10 mm

• The team can include a maximum of three members.
• All members of the team should be enrolled as students in an educational institute.
• No person can be a part of more than one team.

Kaustav Sengupta     - (+91) 9008419767
Kamath Ajit Manohar - (+91) 8904818496