Tower transformed to protect the past

The project, explains Jeremy Ashbee, head properties curator at English Heritage, was “very much to maintain Clifford’s Tower as a ruin and not pretend that it is something it isn’t. If we had recreated it as a building it would have been wrong on so many levels.”

Not least among the problems of recreating it as a building would have been to decide on which era and for what use, as it served as seat of power for all of the North of England through medieval times and subsequently found uses as treasury and armoury, being a stronghold during the Civil War, before being devasted by fire in 1684. The shell remained while most of the rest of the castle was gradually lost over time, and the Tower became a monument within prison grounds during the 18^th and 19^th centuries.

This current project was therefore to preserve and protect the ruins, particularly vulnerable parts like the upper Tower walls, and provide a more valuable public resource.

The solution was an innovative free-standing timber deck from which steel walkways were suspended at mid-floor height.

“We were keen on keeping the sense of space at the ground floor,” says architect Hugh Broughton when explaining the design. “One of the good things about Clifford’s Tower before had always been seeing all the walls around you. Unfortunately, as architects we are like magpies and collect ideas from all sorts of different places – we looked at how people had dealt with archaeology around Europe. But then you realise there is nothing quite the same and you start from scratch. This is a one off, but then Clifford’s Tower is a one off.”

The deck protects the very top of the walls without placing any strain on them. The weight of the deck – and the 150 people that can be on it at any one time – is carried by the four wooden columns. These are made of Glulam – wood laminate glued together under heat and pressure to provide an incredibly strong, and environmentally beneficial, alternative to steel. The deck allows many people to move around freely and enjoy the views across York. Previously there was only the narrow walkway around the perimeter of the Tower walls, which only allowed one person at a time and a more rushed visitor experience.

The steel walkways are suspended at the same level as the original first floor, so windows and rooms – including Henry III’s personal flushable latrine – can be visited for the first time in centuries.

“The thing with technology that I find really fascinating,” continues Broughton, “and I think it is a potential that has really only evolved in the last 20 or 30 years or so, is this fusion between technology and heritage that allows us to do quite bold things, because the engineering that allowed us to design this structure so that it minimised its impact on the Tower itself comes from quite complex computer analysis of structural loads and we probably couldn’t have done that in the 20^th century to the same degree.

“I really find it quite exciting that you can have a building built in 1245 but you can apply technology 750 years later to give it its new sense of life – and that is something that has happened here.”