Meerhaven Canal Ring

Still water doubles everything. A quay lantern with a poorly controlled upward component appears twice, once in the air and once as a bright inverted image, and the reflected copy is often the more distracting of the two from a boat or a facing window. We modelled the canal surface as a specular plane in the calculations, which almost nobody bothers to do, and then chose fittings on the strength of their 80 to 90 degree intensity rather than their headline efficacy figure.

The ecological constraint was harder and more interesting. The northern arm is a documented commuting route for a protected bat colony, and the consent condition was a maximum of 0.5 lux at the water surface along nine hundred metres of it. We took the lighting off the water entirely on that stretch, using handrail-integrated linear fittings that light only the walking surface behind a 40 millimetre lip, at 1800K, which keeps output almost entirely outside the blue range the ecologists were concerned about.

The rest of the ring is a conventional but carefully layered composition: 2700K on the brick quays, warm graze on the six bridge soffits so each arch reads in the water, and lime trees lit from below at low level and only from November to March. Between April and October the canopy is left dark, because uplighting a full canopy wastes most of its output into the sky and puts a nesting bird under a floodlight for six months.