Cranes are extraordinarily versatile in size and in the purposes to which they are put. Too many operations in private homes as well as industry are still undertaken manually when they could be done quicker, safer and better with mechanical lifts.
The size range of cranes
The machines that lift the smallest loads are the optical tweezers used to assemble nano-machines. However, since they are the size of workbenches they may not be the smallest.
One of the smallest most of us will encounter is the drop claw devices in amusement arcades. Many of these, believe it or not, are perfectly capable lifting devices – but the strength of the claw’s grip is crippled using a variable capacitor inside the box. The “Captain Claw Crane” boasts “A crane worthy of the High Seas” – by which we think they mean piracy not wind turbines.
Offshore wind turbines are a different kettle of fish. The Python foundation crane takes them in its stride. The Python can lift up to 40m. This davit crane uses no hydraulics which improves its environmental safety and reduces costs by about 60% (see https://www.gmh.co.uk/davit-cranes/). But they are by no means the biggest.
Surely the Taisun gantry crane in Shandong, China is the world’s largest. Its lifting capacity is reportedly 20,000 metric tonnes (an entire oil rig: see http://cranepedia.com/gantry-crane/yantai-raffles-taisun-taishan-world-record-crane-20000-ton-lifting-capacity/).
The SSCV Thiaf crane vessel deserves a mention. It is an entire shipping vessel with a lifting capacity of about 14,200 metric tonnes and was used to install pylons for Rotterdam’s Erasmus Bridge.
Like most home builders, industrial enterprises usually only need a crane for a limited period, or need to be able to use it in a variety of places. For this you either need a mobile crane that can travel around a site, or from site to site.
Size is rarely about big and small, but about fitting where you need it. There is a davit crane or tracked for every situation. For example, the Maeda MC104C Spider crane is a small tracked crane only 60cm wide. It nevertheless lifts 2190 lb. They are also used to lower things like coffins into the ground (up to 25’ deep – just in case).
When tracked access isn’t possible, there are also crane kits you can assemble in situ.