Monday, 17 August 2015

Mapping Mountains – Trimble Surveys – Tarmachan Ridge

29.07.15  Creag na Caillich (NN 562 376)    

Creag na Caillich (NN 562 376)

What a difference a day can make!  Yesterday the rain swept in and remained for a number of hours penetrating bodies and ground and yet a few hours and one day later and the sun kissed the hillsides and bathed their colour in warmth.

Today we were back at the base of Beinn Ghlas aiming for the western end of the Tarmachan ridge, this is where the shapely summit of Creag na Caillich is found, this hill is currently listed as a Munro Top.  However, its summit has been surveyed by Alan Dawson with his Leica RX 1250 as being 914.29m high, which is 0.11m below 914.4m / 3,000ft.

By the time Graham parked his car I had already got my boots on and the tripod was strapped to the bottom of my rucksack and a few minutes later I set off in the knowledge that I had to get a good start on John and Graham, otherwise they would be waiting a long time on the summit for my arrival.

A track contours its way around the southern flank of this excellent ridge and gives easy access to its far western end.  As I walked up the track the sun shone out from a beautiful patched cloud sky with Loch Tay spread out below as an elongated sheen.

Looking back down the track to Meall Corranaich

The expanse of Loch Tay

There were moments when I considered putting on my one-skin summer walking jacket as a brisk wind blew, chillying my arms, but I persevered and was thankful I did as the warmth of the sun, and height gained, warmed by body.

The track splits on two occasions with the latter giving access to a small quarry below Coire Fionn Làirige.  As I headed up toward the quarry and our break off point from the track onto open hillside I looked behind and John and Graham were quickly approaching, they soon overtook me and John sped ahead up steep green slopes that were still wet from yesterday’s deluge.

Being caught up

Being overtaken

Gaining height we crept up beside a small stream aiming for the bealach between Creag na Caillich and Beinn nan Eachan.  The former looked like a grand hill with steep eastern sides plummeting down from a pointed summit, whilst the latter was a rounded bulk, protected on its southern side by upper crags.

Graham overshadowed by the bulk of Beinn nan Eachan

By now John had sped off and I occasionally picked out his profile way off in the distance, Graham followed and kindly waited at each point of our upward route that disappeared around a grassed bump until I had come into view, indicating the onward route for me.  This expanse of hillside was marvellous as part of the Tarmachan ridge veered up in front of us with the sun casting dramatic light and the cloud accentuating the effect with shadowed silhouette.

Graham in the great bowl of land under the Tarmachan Ridge

Eventually the ridge was gained and the wind blew in from the north, it was chilly!  As I followed the ridge path John was standing on the pointed summit waiting for our arrival.

John on the summit of Creag na Caillich

Once at the top extra layers of clothing were quickly put on and we used the level and staff to prod around the high point of the hill, this consists of a small grassed area with a few stones indicating a semblance of summit cairn. 

Determining the high point of Creag na Caillich with a level and staff

This small grassed summit area was within a few millimetres from one end to the other, but we determined the high point and John and Graham proceeded to put the tripod and the Leica GS15 over it.  We made a note of the measurement offset with the steel tape of the tribach and set it to collect data.

Setting up the Leica GS15

Graham and John beside the Leica GS15 at the summit of Creag na Caillich

Our next objective was to get out of the wind as it was making our stay somewhat chilly.  John and I found a reclining seat partly out of the wind which we happily made our home for the next two hours of data collection, whilst Graham disappeared around a corner only to emerge and say that he was off to bag a Corbett Top which is named as Meall Tòn Eich on the map.  This looked a long way off with quite a bit of descent to get down to it.

The view from our partly sheltered reclining seat - Meall Garbh

A nice spot to spend a couple of hours as the Leica GS15 collects data from the summit of Creag na Caillich

The view from our partly sheltered reclining seat - Beinn nan Eachan

Toward the end of our two hour wait Graham emerged from his wander and we watched as a person descended our upward route down toward the track corner where we had left to climb on open hillside.  Away to our north-east Meall Garhb pointed skyward with its impressively shaped summit on display.  Further west we could see tiny figures on the summit ridge of Meall nan Tarmachan.  It was a stunning panorama and one that blended from one peak to another in a seamless continuation of mountain form.

Graham on the summit of Meall Tòn Eich (centre of photo)

By the time the two hours of data collection was complete a number of large showers were breaking out on near ground to our north-west, and once the GS15 had been dismantled I quickly set the Trimble up to gather five minutes of data.

The Trimble set up at the summit of Creag na Caillich with Loch Tay in the background

The Trimble set up at the summit of Creag na Caillich with the continuation of the Tarmachan Ridge in the background

As we packed the equipment away I also stripped off the extra layers of my clothes and tried to put them in my rucksack before the wind whisked them away.  Once everything had been packed away we shot off following the ridge path to the steep grassy descent down into the bowl of land and back to the track.

Heading back on the ridge path

It had been another excellent day on the hill and one that was a bonus, as although this hill had been one we wanted to survey we had not planned to do so until discussing it the previous day.

Survey Result:

Creag na Caillich

Summit Height:  914.4m (converted to OSGM15, Trimble GeoXH 6000) 

914.3m (converted to OSGM15, Leica RX1250)  914.3m (converted to 

OSGM15, Leica GS15) (deletion of Munro Top)  

Summit Grid Reference:  NN 56285 37699

Drop:  69.3m (from earlier Leica RX1250 survey)

Dominance:  7.58%

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