The ancient royal castle at Sheriff Hutton in North Yorkshire is a spectacular ruin which looks like it is performing a breathtaking balancing act. Only four corners still stand and the badly decayed North East tower appears to be defying gravity.

But now, thanks to painstaking restoration work and specialist high tensile stainless steel reinforcing bars from Sheffield company Stainless UK, its future is looking a lot more secure.

The 14th century castle, ten miles north east of York, was once owned by King Richard III. Over the centuries it has been ravaged by the weather and robbed of its masonry material.

Repairs to the formidable 100 foot high North East Tower, which is the worst affected section of the castle were part of an English Heritage funded project.

The work involved supporting the whole tower with scaffolding and pinning it together with stainless steel reinforcing bars. The lower levels needed to be stabilised using four 8-meter long M64 tie bars across the arches. These were supplied in Grade 316 stainless steel.

The ties were inserted into holes drilled through the walls and anchored approximately 400mm deep into the one meter thick wall. Central couplers and end threads over 800mm long were used to ensure the bars fitted accurately into the arch.