find many of these in Australia. In fact, I think there might be only two of
So, what am
I talking about?
In the days
of the steam train, locomotives didn’t have the power to conquer steep climbs.
There needed to be work-arounds. The most common one was to reroute the track to
avoid an otherwise insurmountable range. An alternative – not always applicable
– was to construct a spiral around the range that allowed the track to gain the
altitude needed at a reduced rate of incline the locomotive could manage. Sort
of like a spiral staircase.
railway spirals with full 360⁰ loops are on the Sydney to Brisbane single track
line through the Border Ranges on the New South Wales side of the Queensland-New
South Wales border; and on the Melbourne to Sydney double track line between
Junee and Cootamundra just north of the village of Bethungra, but it’s only the
“up line” heading to Sydney that has the spiral.
Junee and Cootamundra in southern New South Wales, trains on the then single
track between Sydney and Melbourne were subjected to long delays as those
travelling north had to be helped up the 1 in 40 incline of the Bethungra Range
by an extra locomotive kept on stand-by at Bethungra. The need for more efficient rail transport on
this crucial line was more keenly recognised with the flurry of war time
movement of personnel and goods. Hence, in the early 1940s a new “up line” to
Sydney was constructed making us of the geography to build an 8.9km spiral deviation
around a hill that added about 2km to the distance travelled by the uphill
trains but reduced the incline to 1 in 66.
Construction of the
construction of the spiral was quite an engineering feat. Cuttings of 27m deep
had to be blasted through the granite hill. Several rock falls over ensuing
years hindered use of the spiral. In January 1994, the spiral line closed for a
four-month rebuild which saw the cuttings widened.
spend time describing how the spiral works – it’s a bit more complicated with a
double track – I’ve made this short video that explains it all.