Initial Design Specifications - Gantry Crane

Following group discussion of various types of cranes already on the market, the possibility of using a gantry crane will be developed for the use outlined in the project brief.

The initial stages in designing the gantry crane will involve looking at the main beam used to support the 1000kg load.

As the load is to be transported 4m from the point of lift, in order to deal with the worst case scenario (where the load has most of its length in one dimension), a length of 8m for the guide rail has been decided upon. This will have implications for the cross-sectional area of the beam as each section is to be designed to weigh no more than 30kg in order to ease transportation.

The following structural shapes are commonly used in industry and may be relevant to our design:

• I-Beam
• Hollow Structural Sections (such as a square, or circular tube)
• Tee shapes
• Rail Profiles (asymmetrical I-beams)

A Universal I-Beam is the most efficient cross-sectional shape when vertical bending moments are applied. It is relatively weak when horizontal forces are applied (i.e. when acting as an H) or when torsional forces are applied.

For both horizontal and vertical forces, a hollow box section is the most suitable. The most efficient shape for bending in any direction is a hollow tube with a circular cross-section.

As the crane is designed to deal primarily with vertical forces, initial designs will focus on the use of an I-beam to support the 1000kg load.