Myrddyn Phillips - Mapping Mountains: Mapping Mountains – Trimble Surveys

Friday, 23 April 2021

Mapping Mountains – Trimble Surveys – Carnedd Wen

22.02.21 Quarry Field (SJ 155 075), Cefn Uchaf (SJ 157 072) and Y Golfa (SJ 182 070, previously Trimbled)

Quarry Field (SJ 155 075)

With rain clearing by mid-morning and forecast sunshine for the remaining daylight hours Linda and I set off later than initially planned. We were walking up the Cefnyspin Lane by 11.45am with increasing amounts of blue dominating the sky overhead.

On our last walk up the Cefnyspin and Frochas Lanes a slight dusting of snow and a crisp chill in the air lingered all day, whilst today it was spring like with lambs in the adjoining fields and the first warmth of the year. It was a joy to be out.

Heading up the Cefnyspin Lane

A few minutes after starting up the Frochas Lane there was a shout from behind and there was Nic with Tommy the dog, it was good to see her and she joined us for the remainder of the day.

The Frochas Lane is delightful; as it follows the crest of a broad ridge and the views from it are extensive. It gains height steadily and looks out on a typical mid-Wales scene of grazing fields, hedgerows and gently shaped hills. During the latest lock down this route to Y Golfa and other near hills has been a release from the confines of the imposed restrictions. It has never disappointed giving good options for circular walks. Today we wanted to extend the walk to two lower hills beyond Y Golfa, both could be Trimbled, and then double back over the higher summit. With our later start we knew we’d be on the higher summit close to sunset and descending the lower part of Llanerchydol Drive as it was turning dark.

First warmth of Spring

We left the Frochas Lane at an intersection and joined a track leading up to a green lane which headed confidently toward the bwlch between the two hills beyond Y Golfa. I’d analysed these with LIDAR prior to today’s walk and as they don’t possess individual names on contemporary Ordnance Survey maps I’d also examined the Tithe map for the name of the bounded land where each summit is situated.

Quarry Field

Our first hill; Quarry Field rose steeply ahead, its greened and pastured south-easterly flank looked inviting set against a deep blue sky as background. By the time we started up the hill I was in plodding mode and watched Linda and Nic steadily pull ahead. As I reached the summit they were sitting on a fallen bow getting ready to have lunch.

Heading up Quarry Field

Lunch time

The summit was under a branch of a tree overlooking a small and now disused quarry. I had no intention to gather five minutes of data and needed a well-earned rest and the warmth and view dictated there was no need to rush proceedings.

Y Golfa from the ascent of Quarry Field

Once the Trimble had attained the 0.1m accuracy level before data should be logged, I pressed ‘Log’ and sat on a near bow of a tree, ate a banana and slumbered in the gorgeous weather. The first warmth after winter’s hold is welcome and to experience this when on a hill is always special and today was no exception. I sat and waited for the Trimble to gather 15 minutes of data before closing it down, taking a few photos and packing it away. It was now time to head off toward our second hill.

Gathering data at the summit of Quarry Field

The Trimble set-up position at the summit of Quarry Field

This was relatively near and once we had back-tracked to the bwlch between it and Quarry Field it was only a short distance to its summit. As I assessed the lay of land and then compared my chosen position for Trimble placement to that produced by LIDAR, Linda and Nic sat a few metres away looking out toward a sumptuous view taking in Cadair Idris, the Aran and the Y Berwyn.

I again had no intention for a quick data collection and this time gathered 13 minutes of data at the summit, with the Tithe map naming the upper enclosed field as Cefn Uchaf. These two hills were a welcome addition to a walk up Y Golfa and can be relatively easily combined with their higher neighbour.

Gathering data at the summit of Cefn Uchaf

Once the Trimble was closed down and packed away we headed back to the green lane which took us down to an old lane heading up the western flank of Y Golfa. This was the route Linda and I had taken on our last walk, so the map was now back in my rucksack and all we had to do was steadily gain height toward a welcome rest outside the Golf Club.

On our way up we found a myriad of lost golf balls which Linda happily bagged for her Dad. This route adds a little wilderness to the walk and beyond the top of the old green lane our route turned to a path beside stunted trees before petering out amongst the browns of copious amounts of bracken. This land is at contrast to that immediately above as the bracken and patches of gorse are quickly displaced with manicured greens and fairways.

We spent about 20 minutes sitting outside the Golf Club, chatting with the person whose family lives there whilst Tommy the dog and the dog from the Golf Club whizzed around the practice putting green, running this way and that, playing to their hearts content.

At the summit of Y Golfa

When we left the Gold Club a chill has set in, the sun had lowered and the magical late afternoon colour had been replaced by a gentled hue heralding the onset of dusk. We were soon beside the trig pillar at the summit of Y Golfa, we lingered for a few minutes for a last look out toward the west and those higher mountains and away we went down the easterly ridge.

Our route down proved a lovey walk as dusk was quickly overtaken by darkness, and was a perfect ending to the day.

Survey Result:

Quarry Field (significant name change)

Summit Height: 268.5m (converted to OSGM15, Trimble GeoXH 6000) (significant height revision)

Summit Grid Reference: SJ 15530 07552 (Trimble GeoXH 6000)

Bwlch Height: 209.6m (LIDAR)

Bwlch Grid Reference: SJ 16489 07601 (LIDAR)

Drop: 58.9m (Trimble GeoXH 6000 summit and LIDAR bwlch) (200m Sub-Twmpau reclassified to 200m Twmpau)

Dominance: 21.93% (Trimble GeoXH 6000 summit and LIDAR bwlch)

Cefn Uchaf (significant name change)

Summit Height: 261.8m (converted to OSGM15, Trimble GeoXH 6000 survey)

Summit Grid Reference: SJ 15739 07264 (Trimble GeoXH 6000 survey)