Gregory/Judbarra National Park – Katherine (280kms)
After the rigours of the previous day, we decided to give the Humbodlt Track a skip. On the way to Katherine, we visited Limestone Gorge. It was full of interest: calcite levees in the (non-flowing) creek; limestone escarpments mostly comprised of dolemite; calcite flows (white flows over grey rocks); and nut trees and baobobs everywhere. The “nut trees” have this amazing chequerboard pattern bark. There were baobob trees in profusion (scientific name: Adansonia gregorii). [A noticeboard said they were introduced from Africa – BS – I think!] We gave a guy a lift over the last 2kms of the track; it was pretty rough and rocky (high clearance 4WD only).
Have I talked about tyre pressures? When we entered the national park, we dropped the tyre pressures all round by about 5-6psi. The main thing is to keep the tyre profile approximately the same all round, so typically the back tyre pressures of the car are higher than the front (30psi v 24psi), and I set the trailer tyres at 24psi. This is for driving over rocky ground; the softer tyres cushion the ride, and apparently make the tyres less prone to punctures (from below, not necessarily from the side). The softer ride also cushions the car and trailer from damage due to vibrations and shocks. In sandy conditions, you drop the pressures even further, so the car and trailer essentially float on the sand. The tyres are lengthened by the process of reducing the pressure, so they act a bit like tank tracks.
We stayed in the Shady Lane Caravan Park for a night, which was my third time there.