Kirstenbosch is soon to have a world-class walkway giving visitors a bird’s-eye view of the gardens though the tree canopy of the arboretum, home to over 450 indigenous trees. The canopy walkway will start just above the concert garden and end near the Dell below the Protea garden. Leading a group of Kirstenbosch guides and interested visitors through the area on Monday, Adam Harrower gave a lively commentary which infected us with his enthusiasm for the project. “The walk will bring visitors closer to the forest ecology – to the birds, foliage and flowers – in this lesser used part of the garden,” he said.
The design of the structure is based on the skeleton of a snake. It will curve its way between the trees , starting at ground level near a 350 year old tree forming part of Van Riebeck’s Hedge, reaching its highest and widest point at 11m above the ground before ending off at ground level again about 135m from its start- all at a gentle slope. Its ribs of regular mild galvanized steel will be covered in a wire mesh, while the platform is to be built of slatted pine and will measure for the most part 1,2m from rail to rail. Some parts will be slightly wider than others allowing for seating and observation points. The handrails will be made from kiaat or gum. ”Before the structure is painted, an artist will give advice as to what shade of green is ‘Kirstenbosch green!, laughed Adam. The painted steel will attract moss and growth.
At present a deep pit marks the beginning and the end of the walk with short concrete pillars which will form the base supports of the structure marking its route through the arboretum. These pillars are housed in eight pits 1.5m deep and 2m wide which have 300mm of concrete at their base, into which ten curving steel bars have been planted and then covered with concrete. The concrete will soon become mossy and unobtrusive. These pillars in turn will support I-beams of 400mm x 400mm which will be hidden from sight by creepers. The walkway is being built off site in 6m long sections.
“Once on site they will just need to be bolted together like a giant Mecanno set,” said Adam. “The problem is how to get them onto the site. One proposal was to lower them by helicopter, but this will be far too expensive. We will probably have to use a crane, doing our best to minimise disturbance to the garden and the visitors to it!”
“The project has been on the cards for the past five years. It was more of a dream than a plan. This year being the centenary and with enough money from bequests, mainly from Mary Mullins, to cover the cost, we thought it was a good opportunity to make some ‘bling’ in the garden to keep us up with the best. Kew Gardens installed a canopy walk four or five years ago. Ours will be unique – snaking left and right and up and down, unlike the one at Kew, which is circular.”
The canopy will cost between R3.5 – R4 million. It is hoped that the project will be completed by the end of October- beginning November this year. Kirstenbosch will also be launching a tree route, of which the canopy walk will form part, taking visitors past 80 of the best trees in the garden.
For photos of the skeleton of the walkway now being constructed as well as an artist’s impression of what it will look like see