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The Berkeley Square T-Rex - ‘Chomper’

SECTOR

COMMERCIAL

LOCATION

LONDON

Project Brief

Detail Lighting were appointed by David Aaron Gallery of Berkeley Square, London to provide lighting for a unique outdoor sculpture installation.

The bronze sculpture was a life sized replica cast of a juvenile T-Rex skeleton exhibit entitled ‘Chomper’. The sculpture was created in a specialist bronze foundry and laboratory in Germany, partly using 3D technology. Known as The Berkeley Square T-Rex, the sculpture is part of Mayfair’s art trail.

Lighting was required to dramatically illuminate the design and features of the statue, and to provide safety lighting for the benefit of pedestrians because the lowest part of the statue was less than 2.5m from ground level.

The main challenge of this project was the lack of mains power supply which meant that Detail Lighting needed to design a battery powered solution that would distribute light evenly while conserving as much power as possible.

We were mindful that LED fittings do not react well to fluctuating voltages, and the voltage supplied by batteries would vary according to the level of charge. We therefore needed to develop a lighting system that would ensure the lifespan of the fittings.

Development

Detail Lighting’s Technical Manager developed a battery system to meet the brief for sustainability and standalone power supply.

To produce optimum capacity without excessive size or weight, two Lithium Polymer (li-Po4) batteries were wired in series to deliver 24v at 100ah (amp hours). Because charging 24v would ordinarily require expensive commercial vehicle chargers, we needed to come up with an alternative system.

We opted to have discreet wiring from the batteries to the connector. The batteries were then charged separately using a dual 12v charging system with the series connection made at the power control unit, making it one series wired 24v pack when plugged in.

With sustainability a key issue, to conserve power while ensuring continuous operation the lighting system was designed to only function during hours of darkness. To control the power to the light fittings, a Mean Well DC variable rectifier, time switch, relay and photocell were installed. This setup ensured that the lights would only operate under specific times of day and/or light levels, preventing unnecessary discharge of the batteries. Rigorous testing was carried out to ensure longevity of the lighting system and stability when exposed to the elements.

The electronics were mounted to a board, then fitted inside a rugged ‘site’ IP rated briefcase. All cables were fed though IP rated cable glands for both strain relief and to prevent ingress.

In depth simulation testing and trials of the lighting effect achieved successful results, giving us the go-ahead to complete the installation in Germany where the sculpture was mounted and constructed before transportation to London.

Outcome

We overcame the unique challenges presented by design and operating restrictions to develop a customised lighting system for this high profile project.

Duration tests on the lights showed a healthy discharge duration of 18 hours, with 20% remaining on the battery packs. Testing was undertaken at 20°c which allowed for the reduced capacity of the batteries in temperatures of 0°c or below. 

The resulting lighting system was completely bespoke. Our designs made the system as user friendly as possible and met quick battery swapping challenges, as well as achieving output stability and battery capacity objectives.

Aesthetically, the lighting effect achieved for showcasing the sculpture of a 66 million years old T-Rex was stunning and captivated the public’s imagination. We were delighted to use our problem solving skills to meet the multi-level challenges of this project.

Lighting products used

Mira 2 (20w)