31 
located, a surveyor was standing by. He could be seen by the engineer and was 
in 2-way radio contact with him. The engineer, comparing his plan with the 
photographs and orientating himself with the aid of the common points mentioned 
above, was able to direct the surveyor into the positions of intersection or tangent 
points of the designed road. He gave the surveyor the corresponding number 
from the design on his plan, which was then noted on the peg accordingly. 
By this method a road was set out without preliminary field investigations and 
surveys. Time and cost for such stages as grade line, traverse and cross sections 
were saved—and in the case of this particular type of terrain the saving was 
quite substantial. 
For the setting out of 24 miles of road along the steep slope of the Tumut gorge 
another procedure was adopted: 
The respective side was covered by phototheodolite survey from 12 bases which 
were connected by a precise traverse and located on the opposite side of the 
valley. Whilst the phototheodolite party proceeded from one base to the other, 
another surveyor was following a given grade line on the proposed road 
site, setting pegs at certain intervals, but especially where intersection points 
were most likely to be expected. These pegs were so placed that they showed 
up on the photographs and could be coordinated and heighted during the 
plotting of contours. By this means a traverse had been laid out on the ground 
along the route of the proposed road without any instrumental observations. 
When the design of the road was completed the offsets from the pegged line for 
  
Fig. 3: Section of the Tumut Valley road at the stage of phototheodolite survey.