Technology & Infrastructure in the 8th century

14 sourced entries, 720 CE to 794 CE, oldest first. Also see Technology & Infrastructure across every century or everything else in the 8th century.

• 720In the Chinese capital of Chang'an, the walls of a gated city ward collapse during the night, which unexpectedly forms a large pool out in the open. This is most likely caused by a sinkhole created when ground water eroded the limestone bedrock beneath. As a consequence of this, more than 500 homes are destroyed (approximate date).source
• 721Rains and heavy storms around the southern seaport of Yangzhou destroy over 1,000 ships and boats in the Grand Canal, during the Tang dynasty (approximate date).source
• 729In Denmark, construction of the Kanhave Canal across the island of Samsø is completed. Although the canal is only about 500 metres long, it is one of the largest engineering projects undertaken in Denmark during the Early Middle Ages.source
• 735During the Tang dynasty in China, by this year there is 149,685,400 kg (165,000 short tons) of grain shipped annually along the Grand Canal.source
• 741Ufenau island in Switzerland is first mentioned in 741 as "Hupinauia", and in 744 as "Ubinauvia" — island of Huppan of Huphan. (Unclear significance)source
• 744Ufenau island in Switzerland is first mentioned in 741 as "Hupinauia", and in 744 as "Ubinauvia" — island of Huppan of Huphan.source
• 744Wat's Dyke, a 40 mile (64 km) earthwork in present-day Wales, is constructed. The border between Mercia and Powys is set here. The date that Wat's Dyke was constructed is very uncertain, with some estimates linking the construction of the dyke to the 5th century and others to the early 9th century (approximate date).source
• 750In China during the Tang Dynasty, a barge load of tea (a medicinal herb) comes up the Grand Canal to Luoyang, from Zhejiang (approximate date).source
• 751Like the storm of 721, the storm of this year at the southern Chinese seaport of Yangzhou reportedly destroys over 1,000 ships engaged in canal and river traffic (approximate date).source
• 754The oldest document mentioning the city of Ferrara (Northern Italy) is from this year (approximate date).source
• 761Construction is completed on the 108-room Castello di Lunghezza outside of Rome, Italy.source
• 770Caliph al-Mansur orders the closing of the Canal of the Pharaohs (Egypt). The only remaining land routes to transship camel caravans' goods are from Alexandria to ports on the Red Sea, or the northern Byzantine termini of the Silk Road.source
• 781New city of Bian (汴) is constructed on the site of Kaifeng during the Tang dynasty (China).source
• 794A paper mill begins production at Baghdad during the Abbasid era, as the Arabs spread the techniques developed by Chinese papermakers. Baghdad becomes a great seat of learning, with Christian and Jewish scholars as well as Muslims, while Europe remains largely unlettered. The Arabs will become the world's most proficient papermakers.source