We started today, in amongst the showers of snow and hailstones, by finishing off the scaffolding tower with the installation of the wooden platform at the top. This took longer than we thought as we dropped a part and broke it.
The next job was to lift each of the legs upright, we tried an arrangement of a rope and pulley hook up to lift up our first leg, number 1 leg at the Great Room end (it’s being one of the heavy one at 160kg) proved difficult to just simply rotate it upwards from its lying down position. The rope was tied to the top of the leg, went up to the top of the scaffold tower, through a pulley and back down to ground level to an electric winch. It was ok in pulling in the rope with plenty of power in the winding, but the scaffold tower started moving around and the leg slipped sideways a foot or two and landed back on the concrete. We were both well clear of the danger zone, we were back at the motorised winch and the control switch at least 10 metres away!
So plan B!
After thinking it through, we decided that we needed a separate crane arm and leg unit to do the job of lifting the legs and the I beams. Since we would have to make this module for dealing with the even heavier I beams, we would make it now and help us lift the 7 legs too! We spent the rest of the afternoon making a double T shape wooden leg measuring 6.8metres tall. It was constructed with a 89mm CLS and a 63mm CLS glued and screwed at right angled to form a T joint.
This leg will form the second leg of the crane module, supporting a horizontal metal bar that has the winch hooked on it (this will allow a much more controlled pulling forces in just the vertical direction) and the other end of the horizontal bar will be fixed to our scaffolding which will form the first stable leg of our crane mechanism.
We will need to do some metal welding to form the connection to the scaffolding tower but that’s not a difficult job and we will do that Monday.