Net benefits

Customers are attracted into the O2 in Dublin by a striking LED mesh, a clever combination of structural engineering and lighting

Architen Lighting is no stranger to working on special projects for O2. It is a veteran of several creative lighting installations at the mobile phone company’s popular London arena, housed in the previously ridiculed Millennium Dome.

The company – which has both lighting and tensile structure divisions – worked with New York architect Jordan Parnass Digital Architecture (JPDA) to create several installations at the London venue.

“The one that was most important in terms of lighting was for the O2 shop,” project manager Christopher Rowell reveals. “It’s an inflated pillow system that’s suspended on the wall, and behind are colour-changing LEDs. They pulsate and change colour or act like a graphic equaliser."

When JPDA was commissioned to design the O2 ‘brand experience’ at Dublin, it wasn’t long before architects Darrick Borowski and Sean Karns were on the phone to Architen. A meeting in New York generated more than 20 ideas, not all of which made it into the final installation.

“One the things that Darrick and Sean were keen to keep, was the LED mesh in the concierge area,” says Rowell. “The architect presented a concept drawing and said: ‘This is what we’re thinking of doing, what are your thoughts?’”

Celestial illuminated cargo net
Borowski elaborates: “We liked the idea of a celestial fabric that was being pushed and pulled in an effect which focused the attention of the customer on the ticket desks. An 2D LED screen would not be capable of the warping and twisting effect we were searching for."

Working with JPDA architects, the Architen team set about finalising the design. “It was to be a ‘cargo net’ suspended from the roof, and we would fix lighting onto it,” says Rowell. “Then we decided we’d like structure and strength, and the net should be a stainless steel-type structure."

"Building the structure was no problem, doing the lighting was no problem, but putting the two together was a problem"

But all was not plain sailing. “We always came up against the same wall,” says Rowell, “which was that building the structure was no problem, doing the lighting was no problem, but putting the two together was a problem. How would we hide the cable between the lights?"

Initially, off-the-shelf products such as Color Kinetics iColor Flex looked like they’d fit the bill, but the LEDs in that product are spaced at regular intervals. “When we started to model the mesh in CAD, we had to have an LED at every node and it was crucial to keep them at a visually consistent pitch,” says Rowell. “Balancing cost and the size of the room, that pitch turned out to be around 230mm. But there were places where the pitch was about 310mm. In the mesh, every dimension is different.

So the designers turned instead to a bespoke system. In one direction there are 50 LED nodes, in the other there are 30, making a total of 1,500 nodes. Each node is 30mm in diameter, and contains four RGB tricolour chips. They are mounted onto a plastic block that accepts and supports the structural cable, and a diffusing lens cap clips onto the underside.

“It was critical to lock the cables off at the right positions for the mesh to maintain its shape,” says Rowell. “We laid out all the cables individually on the table in the factory and literally marked the cables and fixed the nodes on in that position. Then we marked the other cable. On site, they simply lined up the marks and locked off the nodes."

Power and control
The final design hurdle was getting power and control data to the nodes. “We decided that what we really need to do is send the power down the cables that are supporting the LEDs,” says Rowell, “and we spoke to a company, Glasson Electronics, that has done something similar before for our digital festoons."

Shorter cables that span the eight-metre width of the room are positive and the cables that span the 13-metre length of the room are commoned up and grounded. All the positive cables are grouped into sections wired back to power supplies. “Simon from Glasson suggested that we take the 24V supply and inject the control data on top,” says Rowell. “Each of the LED nodes is numbered and they listen for their data. They are individually addressable."

“The more LEDs you run, the longer the text string of control instructions is going to be, and the effects will run more slowly"

An element that extracts power and data is built into each node, and the plastic block keeps everything insulated.

“The critical factor was the number of LEDs you can put in a single run,” adds Rowell. “The more you run, the longer the text string of control instructions is going to be, and the effects will run more slowly. Considering the refresh rate we needed, we came up with 150 LEDs for one power supply, which very nicely divided the thing up into 10 power supplies, each supplying five runs of 30 LEDs.

The completed mesh is capable of displaying low resolution images and simple animations. It is all fed from a Pharos LPC X controller. “The controller spits out its data on Ethernet protocols,” Rowell says, “but because of time and cost constraints, we had to develop the power supplies that drive the mesh with DMX input. So we had to go from an Ethernet to a DMX protocol. We basically had 10 universes of DMX.

Architen has since developed the system to accept ARCnet input.

Client control of light
The client controls the system through a web page. Architen installs GPRS routers in all its control systems, and on the back of that internet router or gateway there is a web page hosted on the control system that allows the client to make changes, set up new programs or turn the installation on and off.

Architen is considering connecting the mesh to the building’s Dali-based lighting control system.

The control system cycles through a range of effects, which are demonstrated in the video below.

Naturally enough, the dominant colour is the corporate blue of O2. There are also moving letter Os and other special effects and colours for particular events. This can be accomplished from anywhere through the control system’s web page.

“There is talk of more interaction with customers, so they can text the system and messages will be posted on the mesh,” says Rowell. “That capability is there. I hope it does happen because it makes it different.”

Project details

Project: O2 Dublin
Client: O2
Lighting designer: Christopher Rowell, Architen Lighting
Architect: Darrick Borowski, Sean Karns, JPDA, New York
Electronics design: Glasson Electronics
Controls: Pharos