Mapping Mountains – Trimble Surveys – Carnedd Llywelyn

31.08.18  Carnedd Llywelyn (SH 683 643, only bwlch surveyed)

The critical bwlch of Carnedd Llywelyn

Having visited Foel Lwyd and Tal y Fan surveying their bylchau and summits I now had an appointment with Janet Ruth Davies, who is a research photographer.  We met outside the Moel Siabod café in Capel Curig and sat in the afternoon sunshine with what looked like the world’s largest scone.

Janet contacted me a few weeks ago and expressed interest in the lines of least resistance, which is the phrase I used to describe how the hill to hill and valley to valley traverse meet and form a critical bwlch.  If weather permitted I suggested we could visit the critical bwlch of Carnedd Llywelyn and Trimble it.

Leaving the café we took two cars toward the small car park adjoined to Gwern Gof Uchaf, a farm that has camping facilities beautifully positioned near the base of Tryfan.  On the way up the A5 cars driving in the opposite direction were flashing their lights, and ahead grey smoke indicated that something was ablaze, it was a car and it looked as if it may explode at any minute as I drove past with flames leaping out of its bonnet.

Thankfully by the time we parked and sorted our gear a fire engine had arrived to douse the flames, but this remained as a near backdrop during the time we were at the bwlch.

A track leaves the outskirts of Gwern Gof Uchaf leading toward Capel Curig, this would have been the old road before the A5 was constructed, it led eastward and we followed it as far as another indistinct track that headed a short distance northward toward the busy road where cars were now stationary as the police and fire brigade dealt with the remnants of the forlorn looking burnt out car.

Heading toward the bwlch

The critical bwlch was only a short distance from where we now were, and I used the Trimble as a hand-held device to zero in to its critical point.  This proved unsurprisingly to be positioned beside a bog.

Having located the position of the critical bwlch which had previously been documented from LIDAR analysis conducted by Aled Williams, I positioned the Trimble atop my rucksack and once the 0.1m accuracy level was attained before data should be logged, I activated the equipment to gather data.  It then stood in place for just over an hour quietly beeping away gathering individual data points, one every second, with 3,650 gathered in all.

Gathering data at the critical bwlch of Carnedd Llywelyn

During this time conversation between Jan and I flowed, and the intensity of the early evening light increased with beautiful colour highlighting the first bronzed tinges of moor grass as summer greenness ebbs in to autumn’s great colour show.

The Trimble set-up position at the critical bwlch of Carnedd Llywelyn

Behind us Tryfan became a silhouetted giant with a backdrop of sky that slowly cascaded in to evening light as slithered cloud accentuated the setting sun.

Jan with the ever present and distinct profile of Tryfan in the background

By now an evening chill had set in, and as Janet and I had exhausted our photographic stock I headed toward the Trimble to close it down.  Its hour long data set is the longest I’ve yet gathered.  It was only a short walk back to our awaiting cars and I waved Jan off before heading down the A5 toward home.

Postscript 

Since the bwlch survey of this hill with the Trimble GeoXH 6000 full LIDAR coverage is now available.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height and positional data that is now freely available for England and Wales.  Consequently the numerical details for this hill has been analysed using this technique, resulting in the LIDAR height and position for its summit being used.

 

Survey Result:

Carnedd Llywelyn

Summit Height: 1062.1m (LIDAR)

Summit Grid Reference:  SH 68375 64349 (LIDAR)

Bwlch Height:  313.7m (converted to OSGM15, Trimble GeoXH 6000)

Bwlch Grid Reference:  SH 67558 60463 (Trimble GeoXH 6000)

Drop:  748.3m (LIDAR summit and Trimble GeoXH 6000 bwlch)

Dominance:  70.46% (LIDAR summit and Trimble GeoXH 6000 bwlch)

For further details please consult the Trimble Survey Spreadsheet

On Location with Janet Ruth Davies

Introduction:

One of the interesting aspects of having a blog is that on occasional I am contacted by someone who expresses interest in what I do.  This usually relates to surveying, but does also take in hill listing and place-name research.  Usually when a person contacts me their motives for doing so are self-explanatory, however on occasion it can also be interesting for me to try and find middle ground where my and their motivations meet, and when Janet Ruth Davies contacted me a number of weeks ago I wondered how my interests and hers could be met.

Janet is a research photographer currently specialising in the erratics of Snowdonia.  She found Mapping Mountains whilst trawling through the Internet and wondered if her inspiration for these rocks could be enhanced by my enthusiasm for surveying and numerical data.

After she contacted me we talked on the telephone, and we both knew that our worlds although concentrating on the outdoors, were extremely different, with one based on eclectic thought and the other firmly placed in practicality.  I wondered how these two worlds could find middle ground where both Janet and I could benefit.  But always up for a challenge I was intrigued by the world that Janet works in and we arranged to meet. 

 

Photographic Shoot:

Prior to meeting Jan I described the line of least resistance followed by a hill walker when on a hill to hill or valley to valley traverse, and described where these lines meet is the critical col of a hill.  Jan was intrigued, and wanted to visit such a point. 

There are many critical cols that are beautiful places to visit, they are varied in nature and one of their appeals is that many are seldom visited.  As Jan lives in Llanberis I wanted to find a critical col that was close to her home and ideally had not been surveyed with the Trimble GeoXH 6000 and was also relatively easy to reach.  A col that met all these stipulations is the bwlch of Carnedd Llywelyn; the third highest mountain in Wales.

Janet Ruth Davies

We met outside the Moel Siabod café in Capel Curig with Jan having travelled north from her work commitments for the day in Dolgellau, whilst I had earlier visited and surveyed Foel Lwyd and Tal y Fan in the northern Carneddau.  It was good to finally meet and over drinks and a giant buttered scone we sat in the late afternoon sunshine as conversation flowed.

The bwlch of Carnedd Llywelyn is placed just to the south of the A5 road and to the east of Llyn Ogwen.  Its position had been identified from LIDAR analysis conducted by Aled Williams and although the construction of the road has altered the near landscape, its critical and natural point still exists close to its tarmacked surface, but firmly planted on what turned out to be relatively dry ground beside a bog.

We left the café and headed west taking two cars toward the farm of Gwern Gof Uchaf where the adjoined small car park would give us easy access to the bwlch.  Approaching the farm a haze of black smoke rose above the road and oncoming cars flashed their headlights, suddenly the cars in front slowed and on the left hand side of the road was a car ablaze with fire engulfing its engine and sides, it looked as if at any minute it would explode, I quickly sped past it and waited for Jan in the farm’s parking area.  Once Jan arrived we wondered how close the car was to where we wanted to visit.

By now a fire engine and a number of police cars were at the scene and their presence and that of the burnt out husk of the car added a surreal element to proceedings.

The proximity of the burnt out car, fire crew and police brought a surreal element to proceedings

Leaving the confines of the small parking area we walked past the farm house and joined the old road as it headed east toward Capel Curig, Jan had cycled this track in the past and we chatted about our experiences of the outdoors.  It’s always of interest meeting people who have an enjoyment of the outdoors, as the environs taking in the uplands can give so much, and this can be enjoyed in so many different ways.  For me this has evolved in to surveying, hill list compilation and place-name enquiries, for Jan it took her to the Alps where she became a shepherdess, and then on to Iceland where she lived for five years, and now back to her north Wales home and through her photography an interest in the Snowdonia erratics.

As the cars were halted on the A5 and the burnt out husk of the car inspected by the fire crew and police, we walked the short distance to where the critical bwlch of Carnedd Llywelyn is placed.  The ten figure grid reference produced from Aled’s LIDAR analysis led us to the critical point and as Jan set her tripod up I explained how the lines of least resistance met from opposing valley directions heading up the Afon Llugwy from Capel Curig and the Nant Ffrancon from Bethesda, and how the opposing hill to hill lines came down from Carnedd Llywelyn and Yr Wyddfa, with the latter passing over the Glyderau and all met at this singular point.

By now the light was turning a succulent hue, giving that magical late half hour when hillsides become ablaze with colour.  The darkened silhouette of Tryfan gave an impressive backdrop to proceedings as the Trimble was set up and beeped away gathering its longest ever data set of just over one hour.

Jan at work with the ever present profile of Tryfan as backdrop

During this Jan set about her photographic duties whilst explaining the intricacies of striated and smooth space, and how these can be developed in landscape photography.  For me, this was a complete re-thinking of how and what photography means, to meet someone with seemingly such abstract thought  concerning a process that I have enjoyed since teenage years was a revelation, and one that I confess I did not fully understand, but it was also one that opened my mind to other thought, which I greatly appreciated.

As the last light disappeared in to the west I closed the Trimble down, and we made our way back to the cars watching the sky delicately changing as bands of cloud highlighted the intensity of deep blue radiating out of the evening sky.

Sunset beyond the Glyderau

Postscript:

I enjoyed Jan’s company and her thought and view; she tested my accepted thought in a gentle way, and this I appreciated.

The Trimble data will be processed and the numerical figure obtained for the critical bwlch of Carnedd Llywelyn will no doubt match that obtained by LIDAR analysis to an acceptable degree.  This will put a figure that man has devised to subconsciously lay foundation to an otherwise natural scene.  This need of man to make sense of landscape by creating semblance of height imposes a foreign element upon an otherwise natural scene.  And there is similarity between this and an erratic; a geological rock, that has found itself imposed upon an otherwise foreign landscape, transported by a glacier many a millennia ago, and it is this that Jan highlighted during our time together.  And it is this form of contrasting similarity that I also question; where my appreciation of a landscape that has given me so much over so many years, has evolved in to one that concentrates on numeracy and its documenting, one seems at odds with the other, and yet they also sit neatly together and enhance my enthusiasm for the uplands that still give me so much. 

Myrddyn Phillips (November 2018)