Tuesday, 21 May 2019

Mapping Mountains – Trimble Surveys – Carnedd Llywelyn


17.02.19  Cribau (SH 732 641), Pt. 504.7m (SH 744 624) and Cefn Cyfarwydd (SH 752 630)

Cefn Cyfarwydd (SN 752 630)

Much of the north-eastern Carneddau are a world apart compared to their higher adjacent hills as their land is dominated by heather which always gives an added sense of wilderness.  These hills stretch from the higher peaks of Creigiau Gleision and Pen Llithrig y Wrach north-eastward toward the coastal plains of the Afon Conwy.

Along with Aled and Mark we planned to visit three of these hills with each being surveyed.  Two of which are marginal P15s and are listed in the Welsh Highlands list (Yr Uchafion) whilst the third; Cefn Cyfarwydd is a potential new Dewey with OS Maps indicating that the 477m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map is in fact on a separate contour ring implying that the critical bwlch is significantly lower.

We met in Trefriw and spent an hour in a café enjoying conversation and laughs over breakfast as the forecast rain materialised.  It was around 10.00am as we indulged in our morning meal, and the rain was forecast to continue until at least midday.  After breakfast Mark drove on the narrow road toward Llyn Cowlyd were he parked and we sat in his car watching the rain and wind sweep in and batter the land around us.

Met office weather forecasts can be incredibly accurate and we had our boots on, or in my case my wellies, and walking in dull but dry conditions by 12.20pm, following the track heading up toward an old quarry above the northern part of Llyn Cowlyd.

The first hill on the surveying agenda was Cribau, which we’d all previously visited, a long time ago for me when I surveyed it with my basic levelling staff.  It has an attractive summit consisting of two tops, each was surveyed and although the rain had stopped the strong wind was still present and I hoped that the Trimble would remain in place during the five minutes data collection on each top.

Gathering data at the first position surveyed for the summit of Cribau

Between the two tops of Cribau

Gathering data at the second position surveyed for the summit of Cribau

I’ve always enjoyed this north-eastern land of the Carneddau with its rock carved summits and thick heather, few people seem to visit these hills compared to their easier underfoot higher neighbours and they have a feel of remoteness and solitude enhanced by the elongated lake of Llyn Cowlyd, which today glistened with brief bursts of sunlight giving a silvery sheen to the grey cloud and rising hillsides above.

Gathering data at the critical bwlch of Cribau

Llyn Cowlyd

Our downward route consisted of the customary bit of heather bashing before the inward track was re-joined; this brought us down to the dam of Llyn Cowlyd from where a convenient path continued through the heather gaining height toward our next point to survey; the bwlch of a c 500m hill positioned between Creigiau Gleision and Cefn Cyfarwydd.

Mark heading up toward the Cefn Cyfarwydd ridge

Pen Llithrig y Wrach rising above Llyn Cowlyd

The bwlch was positioned in a flat-bedded bog and I was thankful for my chose of footwear, which for winter walking in the climate and conditions that lovely Wales sometimes offers are a must.

Gathering data at the critical bwlch of Pt. 504.7m (SH 744 624)

Once five minutes of data were gathered I followed Aled and Mark through the heathery surrounds to the hill’s summit, which consists of three potential high points, with two of these were judged to be candidates for the true summit, they were duly surveyed.

Gathering data at the first position surveyed for the summit of Pt. 504.7m

Gathering data at the second position surveyed for the summit of Pt. 504.7m

By now the grey overhead conditions that had followed immediately after the rain had been replaced by blue sky and a chilling afternoon strong breeze.  During the two summit surveys Mark headed down to investigate the area of the critical bwlch for Cefn Cyfarwydd.  This hill now shone in the afternoon light, a bulk of a hill that looked from this vantage point to easily have the required minimum 30m of drop to qualify for Dewey status.

As I stood upon the summit that had just been Trimbled long shadows cast out against the heather at my feet with Cefn Cyfarwydd beyond.  Once the Trimble was packed away I followed Aled through the rough heather toward a welcoming path that eased passage down toward the area of the connecting bwlch.

Cefn Cyfarwydd

This bwlch consisted of two lines of land that curved round an intermediary heathery bump, whilst Mark succumbed to the pleasures of lying in copious amounts of heather, Aled and I assessed the land and decided that two surveys were required, one from either side of the heathery bump with the placement of the Trimble nearer Cefn Cyfarwydd our favoured position for the critical bwlch of this hill.

Gathering data at the critical bwlch of Cefn Cyfarwydd

It was now 4.30pm and as I followed Mark and Aled up toward the summit of Cefn Cyfarwydd banks of cloud had pushed in from the south-west and any remaining blue sky was now positioned to our north over the sea.

Moel Siabod (L), Creigiau Gleision (centre) and Pen Llithrig y Wrach (R)

It felt good to be on this hill determining its drop after comparing its bwlch spot height against the 5m contouring on OS Maps.  Map research can often give the prospect for interesting survey results and my inclination before processing the Cefn Cyfarwydd data is that it will have sufficient drop to qualify for Dewey status.

As I approached the top of Cefn Cyfarwydd Aled and Mark were standing on its high point which consists of a slight heathery rise amongst more heather.  The Trimble was soon positioned on Aled’s rucksack to give it elevation above its immediate surrounds, the measurement offset noted and the 0.1m accuracy level before data should be logged was soon attained, I now waited for the allotted five minutes of data to be gathered and stored.

Gathering data at the summit of Cefn Cyfarwydd

All that remained was the walk down the hill on what proved to be a good path that led on to the narrow lane which culminated at the continuation of the track leading toward Mark’s car which was parked close to Llyn Cowlyd.

The walk back

As I sauntered toward the car the wind whipped down the valley and the landscape looked stunning in the dusk light.  I slowly plodded my way back on the track happy to be out in such a place. 



Survey Result:



Cribau

Summit Height:  501.9m (converted to OSGM15)

Summit Grid Reference:  SH 73264 64129

Bwlch Height:  487.3m (converted to OSGM15)

Bwlch Grid Reference:  SH 73056 63919


Dominance:  2.90%





Pt. 504.7m

Summit Height:  504.7m (converted to OSGM15)

Summit Grid Reference:  SH 74482 62452

Bwlch Height:  491.4m (converted to OSGM15)

Bwlch Grid Reference:  SH 74150 62406

Drop:  13.3m (Uchaf deletion)

Dominance:  2.64%





Cefn Cyfarwydd

Summit Height:  501.7m (converted to OSGM15)

Summit Grid Reference:  SH 75201 63067

Bwlch Height:  471.0m (converted OSGM15)

Bwlch Grid Reference:  SH 74708 62751


Dominance:  6.11%











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