Resolving a twin Corbett height issue!

Guest post by Myrddyn Phillips

Outdoor enthusiasts will be pleased to hear that an anomaly in the lists of British hills has been resolved by a team comprising The Scottish Mountaineering Club (SMC) and G&J Surveys and Ordnance Survey.

In 1953 the SMC first published John Rooke Corbett’s ‘List of Scottish Mountains of 2,500 feet and Under 3000 feet in Height with Re-ascent of 500 feet on All Sides’ now known as The Corbetts to walkers and climbers of the Scottish mountains.  On that list are two adjacent mountains, Buidhe Bheinn and Sgurr a’ Bhac Chaolais, both of which have a map height of 885m, but a re-ascent between them of only 400ft or so, less than the 500ft required to make them both Corbetts.  The SMC lists them as twins, which has led to much speculation in hill-going circles about which is actually the higher.

So,  action was needed to finally work out which was actually the higher.

The SMC were represented on the day by their President, Andy Nisbet, and Dave McGimpsey while John Barnard and Graham Jackson were the surveyors from G&J Surveys.  John Barnard said ‘The participation of the SMC in the survey of the Twin Corbett was intrinsic to the success of the venture, for as well as being the keepers of the Corbett list, the SMC representatives helped with the survey and carried much of the heavy surveying gear.  This was not a task to be underestimated as we had two sets of equipment’.  He went on to say, ‘We considered this a very important survey and to do it in conjunction with the SMC proved a great success.  We are indebted to Mark Greaves of Ordnance Survey for advising us of the best method for carrying out the survey, which involved placing a GPS receiver on each summit simultaneously and collecting data for three hours.

Mark also processed the data sets to produce the final result.’  Graham Jackson added, ‘Thanks must also be given to Leica Geosystems for the loan of a Leica Viva GS 15 Professional receiver and also to M&P Surveys for the loan of an external power source for our Leica 530, as without their help this survey would not have been possible.’

The surveying team based themselves at Ratagan Youth Hostel in early September and awaited a storm associated with a deep low to show signs of abating.  A weather window occurred on Wednesday 5th September and the survey duly took place.

Andy Nisbet, the President of the Scottish Mountaineering Club said ‘The day proved very enjoyable, albeit wet.  The result that Ordnance Survey has confirmed and the measurement that the SMC will adopt, is that Buidhe Bheinn is 885.50m in height and that Sgurr a’Bhac Chaolais’ is 885.21m in height.  The measured height difference was 0.29m.  I can confirm that the SMC will now list the higher summit, Buidhe Bheinn, as the Corbett.  And although these summits will no longer be listed as a Twin Corbett, I would encourage hill walkers not to neglect the attractions of Sgurr a’ Bhac Chaolais; it is a fine hill in its own right.’

John Barnard, Graham Jackson, Andy Nisbet and Myrddyn Phillips

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