The iconic Iron Bridge in Shropshire has been brought back to life at night with an exciting new lighting scheme, unveiled during the Ironbridge festival, to the delight of local residents and business owners who have endured a torrid year of floods and lockdown.

Iron Bridge Furnace

Iron Bridge Furnace

The Iron Bridge, as its name suggests was the first bridge in the World to be made of iron and as the forebear of modern metal framed buildings, is the worldwide icon for the start of the industrial revolution.  During 2017-18, English Heritage undertook a £3.6m conservation project, repairing cracked joints to preserve its longevity.

Whilst the Bridge had been lit since the late 1970s, the 40-year-old floodlights were life-expired, only lit one side of the bridge and were regularly flooded by the River Severn. A new lighting scheme was required to celebrate the conservation project and the 50th anniversary of Telford new town.

The project seemed relatively simple at the outset. A feasibility study had determined that the flood risk was regularly in the region of four metres, but could be as high as seven metres as seen after storms Ciara and Dennis in February 2020. Columns, resistant to that level and force of water were essential.

English Heritage’s clear instruction as the Bridge’s guardians was that nothing could be mounted on or under the Bridge, cables could not be run through or across it, and that the daytime visual intrusion of any installation must be minimal. Telford & Wrekin Council, as the client, wanted not only a new scheme, but one which would extend the economic day of the towns of Ironbridge and Telford, to illuminate the downstream side which had previously been left dark from a key viewing point and crucially, to celebrate the magnificence of the history of the Bridge.

The original concept for the mid-grey painted bridge was to deliver a white-light scheme for weekdays, a special effect on the weekend and the opportunity to have colour-changing for special occasions.   The weekend effect was actually inspired by an unrelated, but co-incidental quote from Morgan Cowles, Head of Conservation & Heritage at English Heritage, in a Sunday Times article: Imagine the effect of the bridge lit at night by the fires from the furnaces and forges  of Coalbrookdale, the structure glowing a demonic red – the weekend effect would thus become ‘furnace’.

This design could be achieved using unobtrusive columns with integrated RGB floodlight heads to deliver both schemes and enable Telford and Wrekin Council to colour-change on special occasions.  A laser-cut model of the Bridge was procured from the Ironbridge Enginuity Museum to physically demonstrate beam angles on spill light and light pollution to over 20 stakeholders, including Telford & Wrekin Council, English Heritage, Enterprise Telford, Historic England and the UNESCO World Heritage Site Steering Group.

During the conservation project, English Heritage discovered patches of the original paint colour a red-brown, mahogany shade and decided to repaint the whole bridge back into this colour; thus mid-way through the lighting design, with budgets outlined and equipment sizes approved, the paint finish changed from a 25% reflective mid-grey tone receptive to most colours, to a 5% reflective red-brown. To maintain the required luminance with a much lower reflectance would require projectors with much higher lumen packages, these being commensurately larger, more expensive and needing larger, more visible columns.  Instantly a relatively straightforward project became three years of careful negotiation and the overcoming of numerous challenges.

Among these were the geotechnical issues surrounding installing the now heavier columns into unstable gorge sides in a UNESCO World Heritage Site cut through by the River Severn as someone once commented that everything moves in the Gorge, it’s just a question of how much and how fast.

With the Bridge shrouded in scaffold and plastic sheeting for the conservation project, site trials were out the question, so metal sheets and tins of the new paint were acquired to determine the optimum colour temperature and to test that the furnace effect would still work, having acknowledged that RGB was now out of the question.

Detailed computer models of the Bridge and gorge were made to determine quantities and aiming angles to ensure uniformity, whilst minimising glare and spill light through the filigree structure.

To gain planning permission, with the support of Historic England, the use of wooden columns was proposed to soften the daytime appearance. These had bespoke brackets to bunch the projectors tightly together to reduce height, and bespoke bases to ensure that the wooden shafts were well above extreme flood levels. These were then located in as unobtrusive places as possible. The floodlights are mainly narrow beam, cross aimed horizontally to capture as much light as possible on the solid stone abutments to minimize glare and spill light.

To overcome cabling restrictions, the automatic controls talk across the river by radio, whilst GSM links enable Telford & Wrekin Council to change programmes from any computer or smartphone, with a backup system in place to ensure system robustness in case of signal failure.

The final effect delivers a warm white light scheme during the week and the innovative dynamic ‘furnace mode’ of red and amber overlaying a dimmed back white scheme for the weekend; the dynamism is created by altering the intensity of the red and amber floodlights across the Bridge, creating the movement of the light from the fiery skies of Coalbrookdale. The scheme was launched during the Ironbridge Festival and has been applauded by all who have seen it since.

Liz Peck, Design Principal at LPA Lighting, said,

“It’s amazing to see it finally come to life; it’s been one of the most challenging, yet ultimately rewarding projects of my life; there were many days when we didn’t think we’d get to this point, not least when we all witnessed the flood waters in February this year push back the flood barriers in the town, soon followed by Lockdown. The response from everyone in the town has been terrific and we believe this wonderful Bridge now has a lighting scheme befitting of its historic significance.  It couldn’t have been achieved without the partnership with Bob Bohannon and our brilliant clients at Telford and Wrekin Council, who supported us magnificently throughout.”

Bob Bohannon, lighting design partner said,

“It’s been a very special project to us, not only is it one of the UK’s heritage crown jewels, but as well as being experienced lighting designers, both Liz and I also teach at the Lighting Industry Association academy, just up the road. These projects are always a team effort, so huge thanks are owed to acdc lighting, Aubrilam, Lee Engineering and Nick Gibbons at e-on for their respective hours of help. We’ve been visiting Ironbridge for three years now, and met tourists from near and far; we hope the new lighting doesn’t just show the Bridge in a better light, but also entices many others to stay here longer into the evening.”

Client Feedback

Kathy Mulholland, Team Leader Investment & Funding, Telford & Wrekin Council:

A big thankyou to LPA Lighting for all your work; I think it’s a great job and a brilliant lighting scheme! Everyone seemed blown away by it all, particularly of course the furnace effect – and the fact that local residents and businesses are hugely supportive is a clear sign that you’ve got it right.”

 

Phoebe Farrell, Heritage Consultant & Head of Heritage & Conservation, Berrys:

“Liz and Bob took in their stride the continual obstacles and constraints that arose on the Iron Bridge lighting project. Both having an innate ability to combine their technical and design knowledge to come up with creative solutions to make the project work. As well as winning over tricky stakeholders with their friendly nature and explaining to lighting novices the intricate details of the scheme including Historic England and English Heritage who were key partners.”

White Light Scheme

White Light Scheme

Technical Specifications

  • ACDC Fusion 48 projectors, 3000k warm white LED
  • ACDC Fusion 48 projectors, bespoke red & amber LED
  • Aubrilam bespoke Moshi wooden columns
  • Pharos Controller, photocell sensors, 4G Lumen Radio
© Copyright LPA Lighting