Corner of Commercial Road and St. Vincent Street, Port Adelaide

The 'silent policeman' in the centre of the intersection was distinctive and for many years a respected traffic manager at the busy intersection. The black and white column and base was erected in 1939 the third of similar devices intended to manage the traffic. It was replaced with traffic lights on 4 December 1968. The statue in the foreground is 'Justice' on the Workers' Memorial.

The intersection was known as the 'Black Diamond Corner' but there is no generally accepted reason for the name although most people consider that it was so named because the offices of the Black Diamond Line (of ships) was located on the corner.

The intersection looks busy, but there is only one bus in the image and none of the heavy freight trucks now associated with the corner.

Greater Port Adelaide heritage survey Norwood, S. Aust.: McDougall & Vines, 1989

Mudflats to metropolis: Port Adelaide 1836-1986 [Port Adelaide, S. Aust. : B. & T. Publishers, 1986]

Couper-Smartt, John Port Adelaide: tales from a "commodious harbour" Port Adelaide: Friends of the South Australian Maritime Museum, 2003

Rundle Street, Adelaide: with 'silent cop' in left foreground. A real policeman directs traffic.This photo was taken at 2.15 P.M. on February 12th, 1925, to show the traffic

Black Diamond Corner B 24297

Right or wrong the cop always wins in Popular Science September 1926: includes reference to 'silent policeman'

Silent cops make a quiet exit

Flickr: Silent policeman