Standing beneath a circular, stainless steel colonnade in London’s Gasholder Park, nighttime visitors can witness a solar eclipse every 20 minutes. The effect is a lighting sleight-of-hand: LED uplights along the canopy’s perimeter dim sequentially, simulating the moon moving across the face of the sun, creating a dynamic spectacle for both the residents of the surrounding King’s Cross redevelopment and children from a nearby school.
The pocket park is the competition-winning design of London-based Bell Phillips Architects, who organized the space as a series of concentric areas with a circular lawn at the center. Surrounding the green space is a hardscaped walkway from which the restored structure of Gasholder No. 8—an 82-foot-tall cylindrical metal frame constructed in the 1850s to hold coal gas—emerges from behind a newly added stainless steel canopy. The architects tasked local lighting design firm Speirs + Major, who had been involved in the larger King’s Cross redevelopment, to sharpen the material contrast between the cast-iron gasholder and the internal stainless steel canopy and make the park as alluring and functional at night as it is during the day. “The circular layout led us to the idea that we could use light to create both a beautiful nighttime landmark as well as an enlivening immersive experience, inspired by the idea of a solar eclipse,” says Speirs + Major design integrator Philip Rose.
For the solar-eclipse effect, the architects wanted to illuminate each of the canopy’s columns from below, and Speirs + Major chose an in-ground 5000K 1W narrow-beam uplight. The fixtures follow the canopy structure’s architectural rhythm, so that where its columns are positioned more closely together—to provide privacy for the buildings that overlook the park—the fixtures are also densely grouped. (At the northern end of the site, the columns are farther apart to allow views of Regent’s Canal.) Using a lighting control system set to an astronomical clock, Speirs + Major programmed the luminaires to run on a 20-minute cycle—they start at fully illuminated, then dim to off, one-by-one, from east to west over a 3-minute period. After 2 minutes of darkness, the luminaires gradually return to full brightness, again from east to west. The variation in light levels (the light cycle changes according to the lunar calendar) creates a sense of movement and yields shifting shadows and reflections from the column surfaces, animating the park.
The light emitted from the canopy uplights reflects off the polished face of the steel columns and washes onto the pedestrian pathway, producing a kind of corona when viewed from above. In order to accomplish the celestial effect, Speirs + Major had to convince the architects to use a brushed finish for the edge of each stainless steel column, rather than the polished treatment used for the faces. “We had to make sure the material would be coarse enough that the light would be caught on it,” Rose says. Another challenge was making sure that the fixtures were level, in order to align precisely with the 30mm-thin profile of the columns. “Any deviation,” Rose says, “and the light would be spinning off to the side,” rather than hitting the etched steel.
Even when the canopy fixtures go completely dark as they simulate a total eclipse, the park is never pitch-black, since the gasholder luminaires’ remain illuminated. A pair of in-ground 4000K 24W uplights highlights each column and truss that hold the two-level Victorian-era structure together. The restrained lighting makes the gasholder, when seen from outside the park, appear in silhouette and creates the illusion that all of the light is emanating from the corona generated by the interior canopy. An additional layer of light is provided by 3000K 18W-per-linear-foot fixtures integrated into the stairs, ramps, and handrails that connect the site to the surrounding neighborhood. The result is an understated yet ever-changing lighting scheme that ensures a safe and enjoyable visual environment for both residents and visitors alike. •
Details
Project: Gasholder Park, King’s Cross, London • Architect: Bell Phillips Architects, London • Lighting Designer: Speirs + Major, London and Edinburgh • Landscape Architects: Dan Pearson Studio, London (plantings) and Townshend Landscape Architects, London • Engineers: Arup and Hoare Lea • Project Size: 1,590 square meters (17,115 square feet) • Project and Lighting Costs: Not Available • Watts per Square Foot: 0.09 • Code Compliance: Not Applicable
Manufacturers
ETC Paradigm: lighting control system • Mike Stoane Lighting: 3000K 18W linear LED luminaires at handrails • Photonstar: 5000K 1W narrow-beam LED uplights at stainless steel canopy • We-ef: 4000K 24W narrow-beam LED uplights for gasholder structure
