Can you help identify?

Photo 39

1943-09-15. Lae Salamaua isolated. Pioneers working knee-deep in mud and slime construct a road for motor transport 70 minutes after the Australians had landed north west of Lae. To get a foundation the Pioneers laid out tree trunks. Bulldozers and caterpillar tractors went straight into the work of making roads, laying steel mesh strips over soft earth and transporting supplies. AWM id no. 015706