Design Development - Gantry Crane

Following discussion with the group, we have decided to divide the main guide rail into three sections in order to reduce focused stresses on the joints of the beams. Each section will now have a reduced mass, meaning it will be easier to transport.

Key issues with the gantry crane will be the bending moments about the ends of the guide rail and how the legs will be assembled to the rail in order to cope with these forces.

The legs will have to be adjustable in order to ensure that the I-beam is level. As previously discussed, an I-beam is the most efficient at coping with vertical bending forces, yet weaker when horizontal forces are applied.

After discussing this issue with the group, a hollow square cross-section is to be considered as this is a more effiecient shape at coping with bending in both the vertical and horizontal plane.

A solution for the legs could be the use of a tripod at each end. As discussed in our inital ideas, a form of tripod was thought of as an immediate solution for dealing with uneven ground whichever crane design was decided upon. Initially, the idea was to have a tripod on the end of two main legs, similar to this design:

After looking at the use of a tripod crane where the load is lifted throught the centre axis between the three legs (as shown below)


An idea could be to combine the two characteristics and design the legs assembly as below:


The larger the legs, the larger the support in the horizontal plane. This will help ensure the I-beam is as level as possible, thereby reducing the chance that the beam will be subject to horizontal forces.