Plant Equipment and Hire July 2017 | Page 35

An industrial revolution Both ancient and medieval cranes were almost exclusively used for vertical lifting, and not for any sort of horizontal move- ment of loads. With the onset of the Industrial Revolution, the way that cranes were conceived of, constructed, and used changed, becoming more similar to today’s modern cranes. The introduction of the steam engine increased the load that cranes were capable of lifting, with the most famous example of a steam crane likely being the Fairbairn steam crane. The only surviving example of the Fairbairn steam crane is located in Bristol at the quayside dismantled and reassembled higher up during the construction process. Harbour cranes typically comprised a pivoting structure with double treadwheels and were used to load and unload cargo. Cranes at Princes Wharf, and was built in 1878 by Stothert & Pitt based on a design by William Fairbairn. The crane, built from riveted wrought-iron plates, was used to lift heavy loads of up to 35t. In the mid-19th century, British industrialist and engineer William Armstrong designed the first hydraulic crane, used to load coal onto barges at the Quayside in Newcastle. Following the success of this crane, Armstrong established the Elswick works at Newcastle in 1847. In 1850, Armstrong invented a hydraulic accumulator — raised water towers that allowed water pressure to be raised to a constant 42 bar — increasing the crane’s load capacity and allowing machinery such as hoists, capstans, turntables, and dock gates to be used almost anywhere. In a little over a decade, the company had grown significantly, with annual production increasing from 45 cranes Period technologies were used to make a replica of a medieval crane at Prague Castle, based on illustrations from the Wenceslas IV Bible dating from 1390 to 1400.