Mapping Mountains – Trimble Surveys – Drygarn Fawr

01.07.23  Pt. 506.0m (SN 817 554) 

Pt. 506.0m (SN 817 554)

Back to the forested hills above the Tywi valley today, and with only six hills remaining to complete the Welsh Highlands list and with the encouragement from Aled the plan was to knock another one off the ever decreasing total.  This hill was my main objective of the day and is listed as Esgair Gerwyn (SN 788 586), however as a higher prominence hill which is classified as a Dewey is positioned conveniently across the valley and on the way to Esgair Gerwyn, it seemed wise to visit the Dewey first and make more of the day by doing so.

We were parked at the start of the forest track leading toward the summit by 8.50am.  Stepping out of the car was a shock as a chilled breeze blew with flecks of wind-blown drizzle adding merriment to the scene; therefore I put my lightweight fleece on and was glad for its extra warmth. 

Heading up the forest track

The gate at the start of the forest track was locked, which wasn’t a surprise.  Soon on the other side we made good progress up the track as drizzled showers pushed inland toward us.  Looking toward the bleak grey skies to the west the cloud was just above the hills, and one of these was Esgair Gerwyn.  In time the cloud base would rise and patches of direct sunlight would appear, adding flashes of intensified colour to the scene.  This was highlighted by the deepening grey sky, which always intensifies colour when direct sunlight is at play. 

Flashes of sunlight between the showers

As height was gained we passed a section of felled forest, with machinery beside the track, with cut and stacked logs neatly arranged for pick-up.  A short distance beyond and Aled called back that the summit area was free of trees, which was an unexpected bonus. 

One of the hazards of visiting forested tops

Prior to tree felling this section of the hill had two fire breaks leading up toward the summit.  The second of which took you very close to the high point.  This is what I found on my only previous visit in June 2003.  These fire breaks were still evident on the ground, the first adjacent to the still standing mature trees and the second further in to the felled section.  It was this second fire break that would lead us toward the summit. 

A pleasant surprise when the summit area came in to view and it was free of trees

Considering the whole summit area of this hill had recently been felled the going underfoot was relatively easy as we left the confines of the track and headed toward the high point, Aled had recently analysed this hill with new Welsh LIDAR, and using the Trimble GeoXH 6000 as a hand-held device soon took us to the LIDAR high point. 

Heading up the fire break

The felled section gave a number of advantages; easier access to the high point, a summit that could now be Trimbled and the prospect of a view, the latter was only partial as more mature conifers were in front of us. 

Gathering data at the summit of Pt. 506.0m (SN 817 554)

By now the intermittent drizzled showers were massing to wind-blown rain which swept across the summit as the Trimble beeped away collecting its individual datum points.  Once allotted data were gathered and stored I closed the equipment down, wiped the screen to dry it off and down we went back on the easier ground of the fire break to the forest track.  It was here that Aled set off farther in to the forest to visit a sub hill positioned at SN 825 540, whilst I headed down our inward route enjoying the freshness of drizzle and the view farther west, which was now slate grey with more rain massing. 

Aled heading off toward the Welsh Highland Sub which is in the background on the left

Once back at the car I quickly sorted my gear out before sitting in the driver’s seat with a bite to eat, water and a good book.  About an hour after I had arrived, Aled appeared with stories of conifer bashing to get to the trig pillar at the summit of the sub hill.  I was glad that the subs had not yet entailed a compulsive bagging mentality in me! 

 

Survey Result:

 

Pt. 506.0m                                

Summit Height:  506.0m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SN 81733 55429 (Trimble GeoXH 6000)

Bwlch Height:  462.7m (LIDAR)

Bwlch Grid Reference:  SN 81897 54586 (LIDAR)

Drop:  43.3m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  8.56% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet