What is Union Chain Bridge?
{{Infobox bridge | name = Union Bridge | native_name = | native_name_lang = | image = Union Chain Bridge between England and Scotland, 2019.jpg | image_size = | alt = | caption = The bridge from the north on the Scottish bank | official_name = | other_name = | carries = | crosses = [[River Tweed]] | locale = | owner = | maint = | id = | id_type = | website = | architect = | designer = [[Samuel Brown (Royal Navy officer)|Captain Samuel Brown]] | engineering = | winner = | contracted_designer = | design = | material = | length = | width = | height = | mainspan = | spans = 1 | pierswater = | load = | clearance = | below = | life = | builder = | fabricator = | begin = 1819 | complete = | cost = | open = {{start date and age|1820|07|26|df=y}} | inaugurated = | named_for = | toll = | traffic = | preceded = | followed = | heritage = | collapsed = | closed = | replaces = | coordinates = {{coord|55.7525|-2.107|display=inline,title}} | extra = | references = }} The '''Union Chain Bridge''' links England and Scotland across the [[River Tweed]]. It opened in 1820. It is the oldest vehicle-carrying [[Catenary|catenary bridge]] in the world. it is 137 metres long. When it opened, its span made it the longest bridge in the world. It was designed by Samuel Brown who was a British [[Royal Navy|Royal Naval]] officer who also designed cables for ships made from iron chains. It was restored in 2023. The weight limit was raised from 2 tonnes to 3 tonnes. It is is [[Listed building|Grade I listed]] in England and Grade A listed in Scotland. The [[American Society of Civil Engineers]] listed the bridge as an International Historic Civil Engineering Landmark. <ref>{{Cite web|last=Smith|fi