HEMEL HEMPSTEAD, U.K. – Lighting Technology Projects (LTP) designed and installed lighting for the new Alfie Morland pedestrian bridge. LTP was commissioned by developers Dandara Ltd. after seeing LTP's design for the Perryn Road Footbridge in west London earlier this year. The Alfie Morland Bridge is a single span cable structure that traverses the Leighton Buzzard Road. LTP's design needed to conform with BS Standards BS5489-1:2003 + A2:2008 for road lighting, which governs the specific lux levels required to light public bridges and highways.
The LTP team, project-managed on site by Jonathan Adkins and coordinated in the office by Keith Elms, formulated a design and specification that exceeded the required lux levels of 300 or above, using 90 IP67 UniLED handrail fixtures to light the main bridge span.
Each one of these IP 67 rated exterior LED strips gives a 4 Watt output at 6000°K, and is ensconced within the underside of the handrail at a 45 degree angle, mostly concealed from view.
At one end of the bridge, supporting wires are anchored to a lift housing with two elevated arms, and this aspect of the structure is illuminated with four exterior 150 Watt discharge floods positioned on the east and south faces of the lift housing. They were supplied with internal ballasts and 400 mm "stand off" fixing arms and front protection grills.
Another two 35 Watt discharge (NDL) floods with black bodies are located on the north face of the lift housing with four 70W versions for the approach ramp.
"It was about finding a practical solution that was right for the environment, that fitted the aesthetic and could physically be installed without impacting on the impressive architecture of the bridge," said Elms. He added that it was an "interesting" challenge. "Bridges are always very special structures to light, and architectural lighting is a finishing touch that should have great public appeal as well as practical value."
LTP's previous recent experiences of lighting the Fabien Way Bridge in Swansea, the Perryn Road Footbridge and Tradeston Bridge in Glasgow also helped the firm achieve its goals.
In addition to the lighting design, LTP presented all the supporting photometric data to Dandara, along with detailed CAD drawings identifying mains circuit layouts and electrical loading and technical spec of the proposed products.
Once the design was signed off, the lighting installation took place over a month, and the Mayor of Hemel Hempstead officially opened the bridge. Along with its ability to serve as a stylish local landmark, the bridge makes it safer for anyone on foot who needs to cross the road.
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