Ideas for the crane design and safety - Sandra Donohoe

Source:
Strength of materials by Nicholas Willems, John T. Easley, Stanley T. Rolfe, New York ; London : McGraw-Hill, c1981.

Materials

The table from the listed source highlights typical properties of some materials commonly used in construction.

The materials which have the greatest probability in being used as part of the crane structure include: steels, high carbon steel, aluminium alloys.

Steels have the possibility to be used in areas where high strength is required (high Young’s Modulus and a high yield stress) e.g the glide beam (I beam design). However it can pose carrying issues for the workers over long and uneven ground, due to its high mass/weight density.

A design that could be looked into for the glide rail according to BS5950-1:2000 (structural use of steelwork in building - part 1: code of practice for design- rolled and welded sections), include the use of castellated beams of the following dimensions (stresses would need to be calculated however it can reduce the weight issues but would be more expensive than a standard I beam ):



On the other hand as the region is currently susceptible to aftershocks, collapse of infrastructures… rescuers will be working in potentially dangerous conditions, to avoid toppling over of the structure the extra weight (e.g. of the steel) could provide some stability if such events were to occur.

Aluminium alloys possess a low mass/weight density and a relatively high yield stress but also have noticeably lower E value (than steels) proving strength per weight and less brittleness than steel. Aluminium however has the disadvantage of being more costly than steels as it requires more specialised manufacturing and repair processes, however due to their chemical properties are generally more resistant to corrosion.

Once the rescues has been completed and most of the rubble removed, if there are no further uses for some of these cranes, having produced them using these types of materials would allow them to be recycled and be considered environmentally friendly.