Spreader bar crane lift
It fits really nicely, and feels very secure on there.
The thumb is a great addition to my digger.I am now in the market for one on my other digger.
#SPREADER BAR CRANE LIFT MANUAL#
To help put this into perspective I have redrawn the diagram with the slings underneath the spreader beam having a wider ISA angle than those above. Higher up the rig, where the spreader beam is placed there is no change in the angle of the force from the bottom slings to the top slings, therefore there is no resultant force created to compress the spreader. As discussed in my first article, it is the angled sling which creates the inwards (compression) force, and in this example this force acts at the point where the angles change. The reason the load takes all of the compression in this example, is because this is the point at which the force pulling downwards (created from the weight of the load) travels into the angled sling. The first point to make is that if the spreader beam was removed from this there would be no change to the sling angle and no change to the forces in the load. When presented with the above scenario, many would argue that the spreader beam would perhaps share the compression force with the load, but this is not the case. In this example, the compression force is entirely taken by the load itself – indicated by the red arrows in figure 2. Let’s get straight to the point then, the beam in this image isn’t being used correctly, in fact, you could say the beam in this image isn’t even being used! It is difficult to be sure from the photo, so to start with in figure 2 I have assumed that bottom slings maintain the same angle as the top slings (it actually looks as if the ISA angle widens which I will deal with later in this post). To help explain what is going on in the above image, I’ve redrawn it (see Figure 2).