Old techniques can be environmental winners

“We do a lot of dry-stone work, which is a lost art,” says director Brenton Collins, “and we’ve moved rocks like the Egyptians.”

At the time of writing, TSA was working on four separate sites.

Summit Track from Waterfall Gully to Mount Lofty summit is SA’s busiest trail with 400,000 users a year, TSA is in a team managed by Camco SA that is upgrading a 3km section from the top of First Falls to the summit.

“Operating on the trail while it is open to the general public has presented a huge challenge,” says Collins. The old surface has been stripped and reconditioned as a sub-base for a capping layer and large rocks now anchor the trail. These, along with passive water treatments, create a more natural bush experience as well as help increase its sustainability.

TSA designed – and for the past 12 months has been building – a new 2.4km alignment into the waterfall in Deep Creek Conservation Park on the Fleurieu Peninsula, just 1.5 hours from Adelaide.

“We lugged in 500kg of hand tools to the Deep Creek crossing, the nearest access point was 800m away from the work site and we also had 150m of elevation.”

It took six weeks to get a walkable alignment in extremely tough bush negotiating multiple gullies and cliffs. Great care has been taken to minimise the impact on endangered species like the Xanthorrhoea, or Yakka grass tree.

The local foliage can be up to 4m in diameter and present “quite an issue” to work around. “The bush in this area is the thickest I have ever pushed through in this country, and I have walked in every state,” says Collins.

“We have a 3.5km walk in and walk out every day, we try to run a crew of around six and we use a lot of hand tools.”

Remote locations prove inviting

TSA has also done a site assessment/concept plan and feasibility study for a 3km hard build trail for walkers only, in the Ravine des Casoars wilderness area on Kangaroo Island.

As a consultant to DENR, which is building the trail (managed by ranger Cassie Hlava), TSA is training department staff and assisting with construction which is scheduled to finish in late July this year.

The Victor Harbor Council contracted TSA to design and construct stage two of the Victor Heritage Walking Trail – 1800m from the Bluff car park past Petrel Cove to Queen’s Beach. A dry-stone staircase through sandhills was completed recently, random spalls from the local quarry were used to create the stairs, armoured treads and retention walls.

Collins taught himself the mortar-less technique and has been applying it for the past six years, finding it particularly useful in low-lying damp areas and for wet crossings. The staircase was tied into stone on the beach in the tidal zone by building riprap walls and armoured treads with a heavy ballast foundation.

As for moving rocks like Egyptians, this involves Porta Power hydraulic jacks and the Turfer Style hand winch, with these tools a crew of three or four can winch rocks weighing 14t, Collins says.

“We use permapine rounds just like the Egyptians and Incas to move large stone into position to construct walls, stairs and stepping stones, they run on rails if the ground is soft and the rocks are heavy, the rails are 30mm crowbars weighing 11kg each.”