Australian Army trailer Dolly

[cliff]

In WW2 most of the supplies were moved to Darwin with Ford semi trailers. These trailers were #7 McGrath (spell) trailers rated at 7 ton and had a 1941 Ford (Aust) tractor unit.

When the Army recieved Mack NR 10 & NR 12 10 ton 6X4 diesel trucks the #7 semi trailers were converted to 4 wheel standard trailers using a 'Dolly' which consisted of a sprung axle with a draw bar and sitting on top a 'semi-permanent' type turn table the same as that on the Tractor units and the Aussie CMP semi truck units. These were then towed by the Mack's as a standard trailer.

Can anyone help with any details of this 'Dolly' unit please or am I :dh: ?

Photo shows a Mack and #7 trailer like I have discribed above.