Mapping Mountains – Trimble Surveys – Arenig Fawr

 

25.02.22  Mynydd Nodol (SH 865 393) 

Mynydd Nodol (SH 865 393)

Having visited and surveyed Moel Heulog (SH 987 353) I wanted a relatively easy hill to visit before continuing my way toward Nantlle for the weekend with my brother, and Mynydd Nodol ticked all boxes, especially as it is over 500m and qualifies for Dewey status and I had only visited its heathery domain once before, in April 2000 when I remained on its summit for 10-15 minutes admiring the extensive view. 

Time between ascents, and especially ones encompassing 22 years have a tendency to create paths on hills where few previously existed.  These intervening years have also created online logs giving detail of various routes to the summit of this particular hill.  My previous route followed a fence line and I found going on its north easier than beside it on its south, picking up a narrow animal track that took me toward the upper section of the hill.  However, I remember the going was rough in places.  One online log mentioned a path to the south of this fence and as a convenient parking spot close to the start of a track gave access to this fence, this was my chosen route of ascent for the day. 

Leaving my car I joined the track heading directly northward across the western flank of Mynydd Nodol.  The sun cast colour across the land with shadowed patches accentuating the darkened heather, of which there was plenty. 

Mynydd Nodol from the track leading to the disused tip

The track led past a disused tip and proceeded to lose a little height before connecting with the fence line that then strode confidently upward toward the summit.  I left the track at its high point having spotted what I thought a sheep track through the heather, this meandered uphill as a path, always on the south of the fence which was about 20-30 metres away.  The path gave relatively easy progress uphill and only petered out toward the top. 

Arenig Fach and Llyn Celyn

As I headed up I could see an aerial positioned on the summit and suspected it had been set up by a SOTA enthusiast, as I neared the point where the fence joins the summit ridge the person who had set it up was heading my way, we stopped and chatted for ten minutes or so.  He had already been to the top of Arenig Fach earlier in the day and wanted to visit the summit of Carnedd y Filiast before nightfall, my humble two little hill surveying day felt inadequate by comparison! 

Arenig Fawr

I watched him start to descend toward the path I had used on my ascent before I headed across to the ridge path and the large cairn that marks the summit of this hill.  It felt good to be back, but with a gap of 22 years since my only visit I suspect it will be the last time I venture to this particular hill.  Over the intervening years I had passed Mynydd Nodol an inordinate amount of times travelling west and heading back east on the A4212 road beside Llyn Celyn.  When visibility permitted I would always have a quick glance toward the top of Mynydd Nodol and wonder when my next visit would be.  One hill after another always, until today, got in the way, as they are prone to do. 

The 22 year wait for my second visit did not disappoint as the view from the summit was as I remembered; extensive, and although on my previous visit I had spent a number of minutes looking out toward the many hills that are on view, my priority today was to establish the high point of the hill and survey it.  LIDAR gives two options for the summit, both close to one another, with a further point nearer the fence only just lower.  With reports of Abney level surveys on the Hill Bagging website giving a rock beside the large summit cairn as 20cm higher than the point beside the fence.  I assessed the lay of land from a number of directions and came to the same conclusion that the rock beside the cairn was the highest point of the hill. 

LIDAR image of Mynydd Nodol (SH 865 393)

As a brisk breeze blew across the upper part of the hill I secured my rucksack in place with two substantial rocks, one on either side, before placing the Trimble on top aligned with the high point of the rock below, before noting the measurement offset between its internal antenna and the rock at its base.  It only took a couple of minutes for the equipment to attain the 0.1m accuracy level before data should be logged and it was soon then activated to gather data. 

During data collection I stood behind the large cairn out of view of the equipment and let it gather its customary five minutes of data.  Once data were gathered and stored I closed the equipment down, took a few photographs and packed it away. 

Gathering data at the summit of Mynydd Nodol

Leaving the summit I looked back to it as I re-joined the ridge path, after all this would probably be my last visit to this hill.  This feeling of finality has only just entered my conscience; it is due to age and the realisation of time between ascents, it is also the realisation of however many hills there are in Wales, there are always new ones to prioritise and visit. 

I met and chatted with a couple on my way down, the man originated from Aberystwyth and the woman from Cardiff.  They had lived in Y Bala for eight years, so Mynydd Nodol is one of their local hills.  They were on the initial part of the path as it leaves the track.  I waved my goodbyes after ten minutes or so and made my way down to the track, as I did so I peered up and the blue sky from earlier in the day had now been replaced with high cloud giving a late afternoon feel to proceedings. 

 

Survey Result: 

 

Mynydd Nodol

Summit Height:  540.0m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SH 86514 39339 (Trimble GeoXH 6000)

Bwlch Height:  370.8m (LIDAR)

Bwlch Grid Reference:  SH 85660 39014 (LIDAR)

Drop:  169.2m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  31.34% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet