The first task is the clearing of the route, clearing shrubs and trees and undergrowth. The path tray is dug out, permeable membrane is laid, type 1 aggregate laid and tamped down. The whole is overlaid with a topping of red blaes which is rolled to complete.
The licence from Historic Scotland to build this path excluded the use of mechanical diggers on the Antonine Wall so all digging was done by hand.
The Tunnel in the Woods is the poetic name given to the space cleared around the path. The recommended path width is 1.2 metres to allow two walkers to walk side by side. Where the path is designed for horse riders, a height of 3.5 m is recommended. Normally, a path crosses country and is open to the sky. About twice a year new growth has to cleared to maintain the tunnel.
The Path Tray is dug out 150 mm The LoTrak membrane suppresses weeds and, in the case of the Antonine Wall, separates modern work from any archaeology below.
Type 1 is aggregate bottoming used on motorways. Because it is produced in quantity is is relatively cheap. Graded sizes means that the spaces between larger stones are filled with smaller stones and so on down to dust.
The red blaes was bought by West Dunbartonshire Council a couple of winters before to eke out the specious salt. The experiment did not really work as the blaes clagged the culverts. WDC were happy to donate the residue blaes (mixed with a little salt) to out worth cause.