Got some lovely footage there Brian, great pan and zoom! ?
Yarm Viaduct Structure
"The viaduct extends for over 2,280 feet (690 m) in a north/south direction over the town of Yarm and across the River Tees. It consists of 43 arches; 41 of them are 40 feet (12 m) span and are constructed of 7.5 million red bricks. The other two arches are constructed from stone and are 67 feet (20 m) across with one pier standing in the river. The two spans across the river are composed of 139,000 cubic feet (3,900 m3) of stone and are skewed across the river by 20 degrees."
"On the downstream side of the viaduct (eastern side) is a large plaque set into the stone section of where the bridge spans the river. This commemorates the engineers and contractors on the project. Workers on the structure (navvies) were paid £1 per day with the total cost of the bridge being £44,500 by its completion in 1852 (£5.6 million equivalent in 2016). A system of pulleys worked by teams of horses allowed the raw materials to be brought onto the site."