Approaching bridge repairs sensitively is particularly important when dealing with older, historical bridges.
These may or may not be open to the public, but will still hold a value that goes beyond their structure.
When approaching an historical bridge repair, it is however important to weigh up the value of work you are planning on doing, to decide if it is really necessary. Sometimes however, very old bridges are in need of very specific treatment and may have already outlived their usefulness as newer, bigger structures replace them.
Here we will explore some of the options available to people looking for historic bridge repair, and the areas they should consider when planning this work.
Is the building listed?
If a bridge is of a registered historic importance then it is more likely there will be the funding available to get it fixed. The question of historical significance was raised in a recent case in the US where a bridge that had been used by local farmers for over a century was in dire need of repair.
The local community had fought to prevent it being replaced and there was strong local feeling it should be kept. The Green Lane Farms Bridge is a single lane, wrought iron thru-truss bridge that was built in 1889. Already on the National Register of Historic Places, this will be closed for six months while a $1million repair project takes place.
How is it built?
This is an important consideration when considering how to repair a bridge. Many bridges were not designed to carry the loads they carry today, but if you repair an historical bridge using new technology, you need to ask how much are you really conserving its history?
Some of the engineering practices used to build the bridges in the first place are themselves are of historical significance. Consider Clifton Bridge or Victoria Bridge, and how important the engineering elements are to those when planning a repair to a bridge like those.
Even older bridges may be simpler to repair, but require more sensitivity to the historical significance. Small medieval bridges set on ancient trackways are often solid and small, such as the Dunstun Gallox Bridge, which is just 1.2 metres wide.
What are the alternatives?
How essential is it that the bridge is repaired? The factors for this will depend on whether or not the bridge is still in use, what impact closing it will have on the surrounding area and of course, the historical significance of the structure as mentioned above.
It is important to consider local feeling about a bridge in these situations: is there a great desire to maintain an historic monument, or do local people feel they deserve better transport options?
How accessible is it?
Many old bridges were not necessarily built in the best places, or in places that are still in use. You need to consider whether you can get equipment needed to the site easily and whether or not any complications associated with this will add to the cost of the overall repair project.