I'm still downloading photos; this time from the U. of Oregon library website. I just downloaded a particular photo and that had wandering down old memories lane. As I said, I was never a logger, but this photo is of a 'Steam donkey', the power behind a series of large cables that would drag the logs from where they lay, up a hill to a spot where other cables would drag them away to be cut, stacked and loaded. I have increased the size of the photo so that you might see some detail. The 'donkey' was powered by a wood fired steam boiler. Water had to be piped from a nearby stream or spring; uphill from the 'donkey'. The 'donkey' is sitting on a skid made from logs...imagine that! At the end of the log is a short and heavy log with the top made flat so that 'blocks' could be attached to it. Some of what I'm writing is conjecture as there are no details included with the photo, but I'm using a short life time of heavy construction knowledge to fill in what's not included. One heavy cable goes straight out and down on the right side while a second cable crosses over and goes down to the left. Down near the feet of the tall man on the right appears to be a 'snatch block'. Blocks are best described as small pulley wheels, held in a metal framework. A snatch block has a swivel at one end so that it's free to move and always be in the direction of the pull. So you have a straight line pull from the donkey that is converted to a downhill and to the left pull by using a snatch block. Any time you want to change the direction of a fixed line pull, you use a snatch block.
All of this leads up to a memory. The memory of the building of a 14 story office building in downtown Sacramento. Our job was to cover the outside of the building with pre-fabricated panels. The panels were trucked over from our plant in Reno and then, while we blocked traffic on a main street, we would back the trailer down a narrow alleyway alongside the building. When we began the project, there was only a steel structure about 5 stories in height. Ironworkers were adding steel every day. We followed close behind them, welding on the supports that would carry the weight of the panels and allow us to move the panels in or out to maintain a flat exterior. We were also doing the fireproofing; the spraying on of a cementitious material to the steel. Once the building steel was topped out and floor slabs began to be poured, our fireproofing crew could begin. Our panel crew followed the fireproofers. We used machines we called a 'dinosaur' to do the lifting. These were made of a steel framework to hold a heavy duty single phase electrical motor, a winch, a short boom with a snatch block at the end that extended outside of the building and a steel basket at the opposite end to hold about a ton of counterweight iron. All of this rested on six heavy duty wheels.
Here is a website that shows some of the lifting equipment that we used, including snatch blocks.
It all seems simple. Use a heavy duty lifting machine to lift the panels off of the trailer.. Hoist them up and weld them in place. Exactly. Except for the fact that buildings have four or more sides and our panels could only be stored in one place and alongside one side of the building. We had three 'dinosaurs' and half a dozen snatch blocks and that was what we used to move the panels around the building. The panels were usually about 16' long and 6' wide. Made of structural steel and a synthetic plaster finish on one side, open on the other side. We would attach our lifting cables to the top of the panel and rope 'tag' lines to the bottom. One 'dinosaur' would lift the panel off of the trailer while two men held the 'tag' lines. These ropes would help us to control the panel and stop it from spinning as it was hoisted. Once it was free of the trailer we would hoist it straight up about thirty feet and then use clamps to temporarily hold it to the building while we prepared to lift it again, but from a different angle, using a snatch block. The second dinosaur would then begin hoisting and the panel would now move up and sideways across the building. We would do this as many times as needed till we had the panel at the correct side of the building and at the right height. Then it was safely welded in place. I forget how many panels we had on this building but I do know that we never dropped one and we never hurt anyone. Those were my two biggest fears as this was not 'normal' construction. We had just made it up in our heads. I was blessed with having two very clever journeymen working for me and between the three of us, we made it work. We only needed a conventional crane at the very end of the project. We needed a special permit to block 7th Street for the crane and then only for 6 hours while we rushed to finish the job. The building still stands at the corner of 7th and L in Sacramento. I have worked on lots of taller buildings but this one stands out in my memory because of the complexity and danger.