No_2_August_1961 — Page 103

SEC. LIGHTS THE A40 UNDERPASS

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Twin tunnels, 780 ft. long, sweep the A40 straight under London's crowded North Circular Road. The Lighting Division of the G.E.C., responsible for lighting both the under- pass and adjacent roadways, has evolved an interesting and unique system of graduated daylight to ease the contrast between natural and artificial light on the approaches to the tunnels.

220 ft. long canopies over the cuttings leading down to the tunnel entrances reduce the amount of daylight reaching the road surface and enable motorists' eyes to adjust themselves to the light in the tunnel. After dark a lower level of illumination is required in the tunnel than in the daytime and is effected by switching off every other lighting unit.

This is the first underpass lighting scheme to be sponsored by the Ministry of Transport, whose consulting engineers worked closely with the G.E.C. Lighting Division throughout the project.

G.E.C.

LIGHTING DIVISION

The British General Electric Co., Ltd., Union House, Hong Kong.