The Black-Allan line

Spare a thought for the patient pair who marked out our NSW-VIC border!

There is no doubt the COVID-19 pandemic who are usually able to travel interstate without hindrance. A few of us will remember when the NSW border with Victoria was closed and vehicle inspections carried out for fruit inspections as a preventative measure in stopping the spread of fruit fly. SA and WA still have these inspection stations in place, so it’s not unheard of.

We generally accept that the border between Victoria and New South Wales is the Murray River, with its numerous bridge crossings. There is a straight dotted line though, that goes from the middle of the Great Dividing Range to Cape Howe on the east coast of Australia that also defines the border. This is called the Black-Allan Line named after the surveyors who put it in place. A mapping expedition starting in 1870 and finishing in 1872 by Alexander Black and Alexander Allan has defined this part of the border ever since.

The project began at Indi Springs, said to be the Easterly most source of the Murray River and is marked by Cairn No.1. A series of stone cairns and marked trees then proceed along the 176.5 kilometres of the line to Wauka or Cape Howe. Black and Allan used precise trigonometric exercises in putting their observations together to ensure the correct course of the line.

The next time you drive along Highway 1 and cross the well- signed NSW/Vic border that welcomes you into the next State, give a thought to that intrepid team of Black and Allan.