Ahah!

Snapping the website name didn't immediately help, as the site doesn't seem to be there any more. However, Googling the name Brett Mayfield led me to this Stroud newspaper article where there's a video of the gate under construction, including a demonstration of how it moves!

From wander: Long Bemmie Wander with Lisa
Taken: Sun 11 April 2021 16:24
Rating: ★★

GPS Coordinates: 51.43977, -2.60853
Location: Bedminster

Ahah!
Snapping the website name didn't immediately help, as the site doesn't seem to be there any more. However, Googling the name Brett Mayfield led me...