Myrddyn Phillips - Mapping Mountains: Mapping Mountains – Trimble Surveys

04.02.21 Pen y Foel (SJ 179 058) and Y Golfa (SJ 182 070, previously Trimbled)

Y Golfa (SJ 182 070)

Hill walking is a wonderful way to spend a few hours. I rarely arrive back home unfulfilled. It gives solace and with good company can bring laughs a plenty with stunning countryside as a backdrop.

Today I was out with Linda, with two hills planned to visit; Pen y Foel and Y Golfa. The former is a small, unobtrusive hill squeezed between the higher Upper Park to its south-east and Y Golfa towards its north, with the latter proving a delightful hill to visit during lock down. One that gives excellent extended views and a variety of routes for its ascent and descent.

We met at 8.30am outside The Raven and followed public footpaths across muddied fields parallel with the Llanfair Caereinion road, from where the hum of morning traffic meandered across the land.

It was only after an hour or so of our walk up valley that we emerged in to morning sunshine. The sun had been lost behind the Upper Park ridge with us walking in shade whilst it tantalised us across the intervening brook springing out of the Black Pools with bright coloured conditions on the opposing hillside. The sunshine highlighted the rusted winter colour of brackened slopes on Y Golfa and accentuated those wonderful winter greens of grazed pasture.

The beautiful morning gave way to increasing cloud and patchy rain in the afternoon

The footpath soon turned to a track making its way toward Talyrnau and Upper Talyrnau farms, where slurried walkways led past ever so cute calves looking out at us from their pens.

Blue skies dominated the horizon, but with forecast cloud banks and the possibility of rain later in the day we enjoyed the fresh colour that was now with us. Beyond Upper Talyrnau we wandered across expansive greened fields to a lane that gave access to the track leading to Pen y Foel. We used this for a short distance before contouring the upper hillside to the area of the summit.

Pen y Foel (SJ 179 058)

Prior to our visit I had LIDARed this hill for height and position of both summit and bwlch, and this gave an indication for Trimble summit placement. The summit of Pen y Foel looked impressive and especially so to a person that due to lockdown restrictions was now used to the gentle mid Wales landscape having kept my walks local. The remains of its ancient hill fort circled the upper hill, and whilst Linda relaxed sitting beside a fence I set the Trimble up on the highest part of its earthen embankment. This was the first hill that I had surveyed during any of the three lock downs that Wales has experienced over the last 11 months. I wondered if this constituted work, recreation or exercise. As I felt knackered at the end of the walk I decided it couldn’t be classified as recreation!

LIDAR image of Pen y Foel

I took two data sets, the first from the high point of the ancient embankment and the second from what I judged to be the high point beside the fence, with each looking similar in height.

Gathering data at one of two positions surveyed for the summit of Pen y Foel

From here we skirted the near wood using its periphery to make our way around to a sharp, steep decline and a barb wired fence, which gave access down a large field to a gate. Ahead of us over a couple of intervening fields was the small community of Castell Caereinion, which nestled into the landscape against the surrounding green pastured hills.

Castell Caereinion

From here we had a rail and road crossing before the next uphill. Once we had gained a semblance of height we sat on brackened slopes and enjoyed the last throngs of winter sunshine, as the westerly and southerly emerging cloud banks were forever pushing our way.

Winter greens

Leaving the sun behind us we continued uphill following a public footpath toward the Golf Club. Here we sat at a picnic table where Linda thoughtfully produced two beakers for a welcome warmed coffee each.

Approaching Y Golfa from Pen y Foel

Beyond the Golf Club the skies turned grey and by the time we arrived beside the trig pillar atop Y Golfa the first windblown flecks of rain were falling. We didn’t linger and headed down the easterly ridge toward Llanerchydol. The rain increased and kept with us for 30 minutes or so, never too much for me to put my Goretex on, but sufficient to dampen proceedings.

Heading for the summit of Y Golfa

At the summit of Y Golfa with the weather closing in

We sheltered under a number of trees and continued our conversational topics. By the time we set off again the last of the rain had blown northward leaving dulled skies but dry conditions. It was only a short distance down Llanerchydol drive to The Raven passing banks of white dotted Snowdrops on the way.

Snowdrops beside the Llanerchydol drive

After washing our wellies I left Linda with an elbow bump and waved my bi bi’s. All that remained was a slow plod back through the empty streets of Welshpool and the ever welcome canal tow path leading me home. The walk proved a wonderful way to spend a few hours.

Survey Result:

Pen y Foel

Summit Height: 284.1m (converted to OSGM15, Trimble GeoXH 6000) (two points surveyed giving 284.137m and 284.136m respectively, with only 1mm difference both positions are given below)

Summit Grid Reference: SJ 17893 05893 and SJ 17916 05895 (Trimble GeoXH 6000)

Bwlch Height: 194.2m (LIDAR)

Bwlch Grid Reference: SJ 18505 05867 (LIDAR)

Drop: 89.97m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance: 31.66% (Trimble GeoXH 6000 summit and LIDAR bwlch)

Y Golfa

Summit Height: 341.4m (converted to OSGM15, from previous Trimble GeoXH 6000 survey)

Summit Grid Reference: SJ 18247 07086 (from previous Trimble GeoXH 6000 survey)

Bwlch Height: 175.1m (LIDAR)

Bwlch Grid Reference: SJ 16645 06017 (LIDAR)

Drop: 166.3m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance: 48.72% (Trimble GeoXH 6000 summit and LIDAR bwlch)