Beam Length Analysis

The beam length is determined on a few conditions and they are:

• The position of the struts at the base of the leg
• The dimensions of the object to be lifted

1/

The struts position is fixed in relation to the beam so therefore

length of leg at full extension = 1.145m

angle leg sits at = 30 degrees

s.t.f:

1.145 x sin 30 = 0.5725m

however the position of the leg in relation to the object is not that simple. Each leg is 120 degrees from each other and two of the legs sit 30 degrees from the plane which runs parallel with the leg itself.

s.t.f

0.5725 x sin 30 = 0.28625m = 286.25mm

2/

The dimensions of the material is not as big a problem as it would seem, because if we for example take the material to be of a cuboid nature (like in the load dimensions calculated) then if the worst case scenario set is that the material is 4.16m long then we can just work at a different angle by position the crane so we work on a plane with gives more room for the object to moved. However if we come upon a scenario where the material is the same distance no matter what way you take it, for example circular.

The volume of the worst case scenario = 0.3744m^3

s.t.f

pi x r^2 x l = 0.3744m^3

in the previous examples l = 450mm so it will be used in these calculations.

s.t.f

r = 0.515m

So from these two calculated results we can say that if the load has to be moved 4m then the length of the beam must be:

4m + 0.515m + (2 x 0.28625m) = 5.0875m

The beam has also got to have an extra 0.290m added to this length since it must sit in the shoulders. So therefore the overall minimum length needed is 5.3775m

With this it can be deduced that we need to use the standard length of 5.5m for the beam so that in the worst case scenario picking up the most common material.