Surveyor-General Bags Top Trigs

30 March 2009 Landscan Issue 48

Surveyor-General Don Grant created a little bit of surveying history in December when he reached the summit of Mt Brewster (2515m) in South Westland near Haast Pass.

Brewster bears the eighth highest trig mark in New Zealand, and in reaching it Don accomplished a goal of climbing the peaks with the country’s 10 highest trigs – the fixed points that underpin our survey, land title and mapping systems.

Long before helicopters, pioneering surveyors and chainmen lugged equipment across inhospitable terrain as they went about establishing the geodetic network from the early days of settlement. Trigs were established on accessible peaks and hills – in most cases a two inch pipe set into the rock over which a theodolite could be placed. The familiar surveying icon, the 4m high, four-sided beacon, came to grace many of the trigs around the country. Their design allowed the trig to be seen from distant mountain tops and, as a side benefit, a canvas tent to be wrapped around the beacon to shelter surveyors while they did their work.

While one of the Surveyor-General’s functions is to ensure trig marks are well maintained, climbing the highest trigs was for Don as much personal ambition borne from his enjoyment of tramping and climbing as it was professional interest. When Don climbed Marlborough’s Mt Tapuae-o-Uenuku in 2006, he became the first Surveyor-General to reach New Zealand’s loftiest trig, located on the summit at 2884m. For the record the mark was still in place, though a pipe attached to it had been bent over by snow. Don says the idea to climb the high trigs had “evolved” after an earlier climb of Tapuae-o-Uenuku in 1998. After his appointment as Surveyor-General in 2005, Don convinced several of his tramping and climbing mates to give up weekends and holidays to take up the 10 trig challenge. The other trig points fell: Mt Ruapehu (three trigs in two climbs), Mt Taranaki, Mts Manukau and Te Ao Whekere (both on the Seaward Kaikoura Range), Mt Gladstone and Mt Cold (on or near the Inland Kaikoura Range).

While physically demanding, most were straightforward climbs requiring little technical climbing know-how, but Brewster was left till last because it was always going to be the most challenging. Preparation for Brewster involved two alpine instruction courses at the Sir Edmund Hillary Outdoor Pursuits Centre, honing skills on snow routes on Ruapehu and Taranaki, and an ascent of Mt Travers in Nelson Lakes National Park– coincidentally New Zealand’s 11th highest trig point. For the climb itself, the team hired two mountain guides to see them to the top. After waiting several days for good weather, they bagged the peak after a climb involving steep snow, a rock step and negotiating the narrow summit ridge.“I was pretty nervous on the ridge; the biggest thing about the climb was overcoming doubt that I could do it.” To top off the climb, the remains of the disused trig beacon were still there for the Surveyor-General’s inspection.

The installation of the Brewster beacon in 1979 turned into something of an epic. Although the materials were flown to the summit by helicopter, surveyor Alan Gough (a competent climber) wisely reckoned they should climb to the summit so that he and the two chainmen assisting would know the route down if weather prevented a helicopter pick up. Which is precisely what happened. Roped for the descent, in whiteout conditions and steady snowfall, the leading chainman slipped and dragged off the other, but fortunately Alan had them on a good belay. They eventually emerged below the cloud and were lucky enough to be picked up by helicopter before dark.

The 16 hour day Don and his companions spent completing the Brewster climb, and the other climbs they did have given them a profound respect for the work of early surveyors, Don says. “Unlike us, they didn’t have modern climbing gear and instead had to carry heavy survey equipment and tools up the mountains.”

Several prominent New Zealand surveyors-general have been memorialised in names of Southern Alps peaks – S. Percy Smith and Thomas Noel Brodrick to name two, so a suggestion that Don’s next goal might be to climb some of those peaks draws at least a thoughtful scratch of the chin!