Mapping Mountains – Trimble Surveys – Moelwyn Mawr

 

22.09.21  Cefn Coch (SH 610 396) 

LIDAR image of Cefn Coch (SH 610 396)

Sometimes a walk can take on a surreal aspect where one part is in utter contrast to another.  This hill was such an example.  Cefn Coch; with the name appearing on the Ordnance Survey One-Inch ‘Old Series’ map, is positioned above the town of Penrhyndeudraeth and is one of many similar hills in this area that qualify for P30 status that are both wooded, rocky and seemingly pathless. 

We had hoped to visit Moel y Dyniewyd (SH 612 477), but low cloud and rain meant our plans were quickly rearranged.  The weather conditions dictated lower summits and Aled suggested visiting three hills, with Cefn Coch the second, all of them wooded, which would at least shelter us from any continuing drizzled rain.  However, this also meant that I had not come prepared with the ten figure grid references for each hill. 

Moel y Dyniewyd (SH 612 477)

We approached Cefn Coch from the east having parked in a large lay-bi on the A4085 road just below its connecting bwlch.  We walked up the road to where a public footpath sign confidently pointed toward the direction of the hill.  This we followed and then started to gain height giving views across Traeth Mawr to the higher Eryri peaks. 

The Yr Wyddfa massif was still cloaked in cloud as were the higher Moelwynion, but Cnicht stared back at us, standing out with its shapely profile easily identified.  Across the intervening flatlands Moel Ddu stood out with a cloud enshrouded Moel Hebog beyond.  From where we now were this view was to be savoured and more so as earlier in the morning the gloom was almost down to road level. 

The view of the Yr Wyddfa massif before the brambles overwelmed us!

This view was at contrast to what we found the higher up the hill we went.  Online logs gave a foretaste of the undergrowth encountered, with numerous visits finding a pathless morass of brambles. 

I followed Aled as he negotiated a way upward, initially a path of sorts made its way through bracken, but this soon lost interest and disappeared when the first brambles made their entrance.  Soon afterward we encountered a wall which was easily negotiated.  On the other side more bracken and brambles led to a rock outcrop which we slithered up and over.  More brambles emerged beyond! 

We reached a point that could have been the summit, but before setting the Trimble up, Aled investigated farther on and soon called me to join him as he was standing on higher ground.  Not satisfied with this position he again investigated farther in to the mass of undergrowth and reached a point that looked as if it was the summit.  Without a ten figure grid reference for the high point we were unaware that we were still 100 metres or so from the true summit.  By now my legs had been torn to pieces with bloodied scratches making a patchwork of patterns. 

The point we were now at consisted of a large mossed rock and soon the Trimble was set up gathering data.  During data collection we sat below the equipment and debated the fineries of what constitutes a published hill list.  This subject has direct relevance to a project we are currently working on, so time now permitted that we could discuss the details at length. 

Gathering data at the point we thought the summit

Once allotted data were gathered and stored I closed the equipment down, packed it away and followed Aled through the jungle of brambles and down the slithery rock to finally emerge back on the public footpath.  It was only a short walk from here to the awaiting car. 

Back through the jungle of brambles

When back home I processed the data and checked the co-ordinates against those on the Hill Bagging website and from LIDAR analysis.  Once data were processed it was obvious that the Trimble data set was not good, which was not a surprise considering the enclosed nature of where it was taken from, therefore this will not be used.  The co-ordinates confirmed we were approximately 100 metres from the high point of the hill.  Hopefully a repeat ascent in winter to the true summit will give my legs a chance to survive the experience, when wearing trousers instead of shorts will protect them from being scratched and bloodied as they had been today. 

 

Survey Result: 

 

Cefn Coch (significant name change)

Summit Height:  86.6m (LIDAR) (significant height revision)

Summit Grid Reference:  SH 61030 39620 (LIDAR)

Bwlch Height:  51.5m (LIDAR)

Bwlch Grid Reference:  SH 61461 39763 (LIDAR)

Drop:  35.1m (LIDAR) (30-99m Sub-Twmpau reclassified to 30-99m Twmpau)

Dominance:  40.51% (LIDAR)

 

 

For further details please consult the Trimble Survey Spreadsheet