St Pancras International, London

HS1, the owners of St Pancras International was looking to upgrade the legacy lighting on the upper deck of the station’s main concourse. The key drivers behind the decision to switch to LED technology were to reduce energy bills, as well as significantly reduce the time and cost to maintain the existing luminaries.

The biggest challenge in terms of maintenance was the fact that the fittings were installed at a high level, with high bays in particular fixed into the roof, which sits at around 100 feet high. Replacing and repairing the lamps posed a logistical challenge for the station’s contractor NG Bailey, specialist equipment was required, each scheduled maintenance round required a three-strong team and timing was key as the station never closes. Additionally, in many instances, secure access involved the closure of lines, which took time to arrange.

Moreover, as the station and its fittings were Grade I listed, the LED retrofit project had to be completed in line with good conservation principles and agreed with English Heritage.

Zeta worked closely with HS1, NG Bailey and English Heritage, developing bespoke LED retrofit gear trays and conducting trials to ensure that the solution provided met all parties’ requirements.

One of the key requirements was to retain rather than replace the historic luminaries, ensuring the overall aesthetics remained the same. This meant that converting to LED technology was reliant on Zeta designing and developing bespoke retrofit gear trays that would work within the existing housings. The colour temperature and intensity of light was also refined by Zeta in order to meet English Heritage’s stringent requirements.

Zeta has many years’ experience developing modern LED retrofit systems that work within heritage sites, making them ideal for use in historic locations and listed buildings. As all development is conducted in-house at its Bicester production facility, Zeta was able to quickly respond to feedback from English Heritage following the early stage test and trial process, and refine and adapt its retrofit systems to conform to all requirements.

This agility proved to be very important during the installation process. The project plan set clear targets regarding the number of retrofits to be completed within each shift. With equipment hire, contractors and arrangements to cordon off parts of the station organised well in advance and at significant cost, it was critical that the retrofit gear trays were onsite, on time, every time.

To the naked eye, the aesthetic of the station remains the same – this was a non-negotiable condition set by English Heritage. However the lighting is now much more energy- and cost-efficient. One of the biggest benefits of LED technology is a significant reduction in energy consumption. LEDs consume on average 70 per cent less energy that traditional lighting technology and also lower carbon emissions at a similar level. With the lights in the station on around the clock, HS1 can expect to realise a strong and fast return on investment. The resultant energy bill cost savings for the 118 high bays are expected to be £13,000 per annum while powering the 208 wall washers will deliver an annual saving in excess of £22,500 each year.

LEDs have a typical lifetime of 100,000 hours, and are ultra-reliable, as such they do not require frequent replacement compared to traditional light sources. This will prove to be a major benefit, freeing up time for NG Bailey to focus on maintaining other areas of the station. Furthermore removing the requirement to regularly replace and maintain the lighting, eliminates logistical issues around securing line closures, closing off areas of the station to the public, as well as ensuring the appropriate staffing levels to complete the works. HS1’s spend on lighting maintenance was almost £190,000, a significant sum it will now save each year thanks to Zeta’s LEDs which will provide an approximately ten-year maintenance-free period.

Zeta’s expertise played a key part in enabling the LED upgrade project to run smoothly. The station is now illuminated with energy-efficient maintenance-free technology and Zeta’s bespoke retrofit solution meant the legacy housings could be retained, a key requirement for English Heritage.
Aara Astourian, Assistant Contract Manager, Network Rail High Speed