Sandfield swing bridge is a typical example of the swing bridges along the Gloucester & Sharpness Canal. They are manned by CRT staff during their normal opening hours (seasonally dependent). They can be contacted by VHF or telephone on approach, but appear to keep a good enough lookout for boats coming and will swing the bridge clear, giving a green light on their traffic signal. There is a project being trialled (2015) to have them remotely opened using an app for mobile phone. Llanthony lift bridge is also manned. Other bridges having a larger clearance can be opened if needed by telephoning in advance.