Confluence

Lighting and Urban Art Meet Down by the River

Motorists making a nighttime crossing of Melbourne's new Bolte bridge are unexpectedly presented with one of Australia's largest works of lighting art: an entire grain terminal as the canvas for a projected work titled Confluence.

It's a project designed to recall the city's history. Originally a meeting place for the Kulin Aboriginal nation, the European settlement of Melbourne was established in 1835 on Port Phillip Bay at the mouth of the Yarra River. By the late 19th century, Melbourne had become Australia's largest and most prosperous city. Its busy ports poured out wheat and wool to Europe, receiving back manufactured goods for the colony's rapidly growing population, as well as more immigrants.

With the advent of container shipping and bulk handling in the latter part of the 20th century, substantial parts of the city's docklands had fallen into disuse and, by the end of the 1990s, plans were underway to redevelop these derelict precincts. One such project was the construction, by Grainco, of a state-of-the-art terminal for the bulk storage and shipping of grains, pulses, and oil seeds. This new facility, on the site of the old Appleton Dock, consists of 20 silos with a capacity to store 48,000 tons of grains.

A grain terminal, as with every major construction project in the state of Victoria, is required to include an element of urban art. To facilitate this, Grainco engaged arts consultant Elizabeth Walsh to compile a brief for the work and to assist in the selection of an appropriate project.

Walsh had previously lived in the vicinity of the docklands area and she recalled the drab industrial area's nighttime transformation into a landscape of lights and reflections off the water. The concept of transformation, together with the grain terminal's proximity to the newly constructed Bolte bridge, became key elements in Walsh's brief.

The project selected for the site was Confluence: a Meeting of Waters, a collaborative work from artists Glen Romanis and Megan Evans, working in conjunction with lighting consultant Braham Ciddor of Lightmoves. The concept for their work is that, by night, the silos are transformed, by projected images, into a stylized map of the waterways that converge at the site. The map depicts the trade routes through the area originally followed by Aboriginals and more recently by Europeans.

Due to the distortions involved in viewing a map stretched out over ten cylindrical silos, the complete image can be seen only from a limited number of viewing positions. Romanis and Evans selected a 100m (330') stretch of nearby Bolte bridge, itself part of the docklands renewal, as their point of convergence. This viewing angle also coincides with a part of the waterway frequented by sightseeing tours and water taxis.

While large in scale and grand in concept, the silo project was modestly funded, a factor which strongly influenced the choices of technologies and processes Ciddor used to implement the design. The colored imagery is achieved through the time-honored process of gobo projection from ellipsoidal reflector spots. The red ochre land elements of the design are projected by one set of seven luminaires while the blue water elements are projected by a second set. This facilitated the use of relatively inexpensive and robust aluminum templates to compose the images. The design also incorporates black lines to separate and define the colored elements, a technique borrowed from screen printing. These black lines are achieved by simply making the blue river elements a constant amount smaller than the red land elements, into which they fit.

At first glance, the design of a set of gobos intended to project an apparently flat image onto a series of cylindrical silos would seem to be an ideal application for three-dimensional CAD. However, if the budget doesn't allow for CAD, and besides, you are working with artists who like to develop their designs by freehand sketching, then you had better devise an alternate process. Ciddor's approach was to give Romanis and Evans a glass sketch pad: a fine-point marker pen and a set of ultra-high-temperature glass slides that fit into the gobo slot on the custom profile spots.

The image development cycle consisted of (1) making changes to the set of glass slides, (2) reinserting the slides into the luminaires, (3) driving around the city from the grain terminal to reach the Bolte bridge, (4) getting out of the vehicle in the viewing zone to check and record the progress of the work, and (5) returning to the grain terminal to adjust slides.

Romanis and Evans, together with the Lightmoves crew, repeated this process dozens of times during the design development phase, and many hundreds of times over a 10-night period, as they refined the final design. (Their work was not helped by a road traffic official who decided it was his life's work to prevent the artists from alighting as they crossed his new bridge. As a bonus, each round trip also exacted an electronically-collected bridge toll.) The completed glass slides were scanned into a computer where the images were retouched and adjusted for masking and borders before being photo-etched in aluminum.

The ellipsoidal reflectors used, although based on standard 1,200W MSR fittings from Prolite of Queensland, are highly-customized models developed to meet the unusual demands of this project. Unlike most profiles, their shutter and gate assembly is movable, to provide a wider-than-normal range of focus adjustment. The shutter blades are designed to be locked down with screws to prevent any movement of the masking during maintenance. A second gobo holder has also been fitted to the gate assembly to carry a Showcraft gobo rotator that is used to create a moving water-ripple effect in the blue river luminaires.

Perhaps the most interesting optical feature of these luminaires is the 84° beam angle, necessitated by the short throw distances between the boundary fence and the silos. Prolite's luminaire designer, Sean Cairns, achieved the wide angle by the insertion of a third, movable lens group in the optical train. This also enabled accurate focus on the marked surface of the glass slides during the development phase, and control of the softness of the ripple effect in the final setup.

The 14 luminaires are mounted in rain- and seagull-proof enclosures at the top of 8m (25') towers along the boundary fence of the terminal. As this land was only recently reclaimed from the river, it proved impossible to sink the bases of the towers into the ground for stability. Instead, they are mounted on broad concrete slabs, which “float” in the marshy soil.

This project is not a short-term lighting artwork to celebrate a particular occasion. Controlled by a photoelectric cell linked to a time clock, Confluence will be on show from sunset to midnight every night for the next 10 years.

Andy Ciddor of The Kilowatt Company has been a practitioner, educator, and writer in the field of production technology for 30 years. He can be reached at [email protected].