LTP was commissioned by developers Dandara, who co-ordinated the construction and delivery of the bridge, an eye-catching addition to Hemel Hempstead's new contemporary town centre 'Image' development.
Apart from being subtle in terms of the installation and looking fabulous, the lighting design had to conform to 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 co-ordinated in the office by Keith Elms - formulated a design and specification that met and exceeded the required lux levels of 300 or above, utilising 90 x 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, virtually concealed from view, while emitting the correct lux levels.
At one end of the bridge is a lift housing with two elevated arms, to which the supporting wires are anchored, and this aspect of the structure is illuminated with four exterior 150 Watt discharge floods, located on the east and south faces of the lift housing, supplied complete with internal ballasts and 400mm 'stand off' fixing arms and front protection grills.
A further two 35W 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," explains Keith Elms. He adds that it was an "interesting" challenge and also a great pleasure to be asked to work on the project, "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."
(Jim Evans)
