Tuesday, 16 September 2014

Mapping Mountains – Trimble Surveys – Yr Wyddfa



09.09.14  Llechog (SH 606 567) and Derlwyn (SH 588 586)

Looking toward Tryfan, Llechog, Crib Goch, Crib y Ddysgl and Yr Wyddfa

For those lovers of symmetry the ridges leading from the summit of Wales’ highest mountain are pleasing in formation.  They plunge downward in dramatic fashion to the summit’s east with ridges comprising Crib y Ddysgl and Y Lliweddd, whilst the western ridges are each split, the southerly of the two comprising Yr Aran and the lower section of the Rhyd-ddu path, with the northerly of the two having the Moel Eilio ridge and what is probably the least frequented ridge on the whole mountain; the Llanberis ridge.

The ridge itself has few visitors probably due to the proximity of the Llanberis Path being one of the main and most popular paths leading up the mountain.  When walking its heights a multitude of budding summiteers file their way on the lower main path neglecting the beauty and solitude just above them.

Today I wanted to visit Llechog, the only 2,000ft summit on this ridge and continue downward as far as Derlwyn, a prospective entry in to the Sub-Pedwar ranks.  I set off at 8.00am from above Llanberis in northern breezed clarity as the sun cast down from a blue and empty sky.

As height was gained the hill’s on the Moel Eilio ridge took on a formidable and friendly feel with their eastern profiles cut to steep ridges and yet their bulk of profile green and inviting.  Moel Eilio itself rather pleasantly gave a delicate shadowed display as strips of darkened hillside seemed to oscillate across its eastern façade.

Moel Eilio (SH 555 577)

Higher on the ridge Moel Cynghorion stood aloof of its neighbours with great sides of green spiralling downward to the upper reaches of Cwm Brwnynog.  These views were enhanced with the triangled summit of Yr Wyddfa poking up above the ridge that continues from Crib y Ddysgl.  A view to savour as so often it is obscured by cloud.

Moel Cynghorion (SH 586 563)

As I made progress up the path two couples descended about ten minutes apart, and both having walked up during the night to watch the sun rise, they said that it was beautiful to see between the bouts of hyperthermia! 

Approaching the café at Halfway House I came across a number of signs proclaiming that Snowdon was for sale.  The prospective sale is of lands owned by Dafydd Morris, a farmer I once met when doing a round of these hill’s, I had ventured off piste and was heading for my car parked high above Llanberis at the foot of Moel Eilio, I’d often taken the route I was then on, but unbeknownst to me the house named Hafodty Newydd was being renovated by Dafydd and his son, as I appeared around the corner of the house I was met by Dafydd who quisickly asked if I knew that I was not on a right of way.  Within a few moments Dafydd was showing me inside the house and telling me about the community that once lived high in Cwm Brwnynog.  He proved a lovely man to meet and he is now selling much of the land he owns.  It is also Dafydd’s family who renovated and now run the Halfway House café on the Llanberis Path with Alwena; Dafydd’s daughter, being chief patron; a lovely woman.

Snowdon for sale, any buyers?

Beyond the café the path steepens and gave views westward toward Crib Nantlle, from this angle a maze of peaks one butted against another, framed by Bwlch Cwm Brwnynog, opposite these hills was the outlier of Mynydd Mawr.

Bwlch Cwm Brwnynog framing Crib Nantlle

As the path crests the ridge it intersects with the railway next to Clogwyn Station.  I decided to have a look inside and say bore da to its occupants, they were busy at work enjoying a morning panad.  The scene resembled one from a Dickensian back street as sunlight was almost non-existent and blackness ruled.

Clogwyn Station from the outside


Clogwyn Station from the inside

Clogwyn Station is positioned at 779m (2256ft) which is over 50m higher than the first hill I wanted to visit, so a bit of downhill towards Llechog was needed.  The advantage of overshooting the hill and descending to it is the view when approaching the hill from its south as its shape of rock lunges skyward with its easterly flank plunging almost 600m down to the Afon Nant Peris in the valley below.  It is this side of the hill that sports an interesting scramble if taken straight on from the road below, I once did this and only veered off the direct route nearer the top as I thought the day’s adventure then sufficient.

I’d wanted to visit Llechog and accurately re-survey it for a number of years as I attained a drop figure of 97½ft (29.7m) with my old staff, whereas it is listed in Alan’s excellent TACit publication as a Sub-Hewitt with c 23m of drop.

Llechog (SH 606 567)

The area of the critical bwlch for this hill is only small; I chose my spot and waited until the 0.1m accuracy had been attained before data can be logged.  The position of the Trimble was within a couple of metres of the side of the railway track and I hoped that my arrival was timed to miss any trains, after all it had survived being run over by a car but I thought a train may be a teense too big for it to take on.

Gathering data at the critical bwlch of Llechog


The Trimble set up position at the critical bwlch of Llechog

Once data were stored I proceeded up to the summit, which comprises an elongated substantial rock.  As the Trimble clung on to the high point I sat and watched one of the trains as it stopped just above the bwlch, I wondered what the passengers thought of this lone figure that was dashing up to the high point, peering in to a small yellow contraption and then quickly ducking out of sight.  This happened on numerous occasions as the Trimble attained the 0.1m accuracy.

The Trimble GeoXH 6000 gathering data at the summit of Llechog


The Trimble set up position at the summit of Llechog

Descending from the summit of Llechog I looked across to the Glyderau and the rocky profiles of their higher summits contrasting with the friendlier graduated outlines of Y Garn and Elidir Fawr, the latter’s old quarry system forever edged in to the mountain.  Once this was the second largest working slate mine in the world, now it is an industrial scar that is highlighted in its blues and greys and stepped sides.

The old quarry on the slopes of Elidir Fawr

As I crested a 644m map heighted hill a party of walkers from West Kirby approached, we stopped and chatted for a few minutes, they were doing a similar walk to me but in reverse, we commented on how good this ridge is and how few people seem to come this way.

The party of walkers from West Kirby

The downward ridge from Llechog continues over the two Tryfan peaks, both fine steep sided hills and proceeds to the outlier; Derlwyn, which is a 416m map heighted hill that I’d estimated having a c 18m of drop and therefore it doesn’t make it to the ranks of Sub-Pedwar hills.  When assessing the hill on the map the area of the bwlch has two possibilities for where its critical bwlch is placed.  When on the ground there is only one distinct possibility for the critical bwlch, this was near to a ladder stile and as the Trimble did its stuff I sat and waited, feeling very content with the day’s progress.  Looking back on my downward route the lower of the two Tryfan peaks stood impressive with its rock shaped outline bathed in sunshine.

Looking back up the ridge toward Tryfan


Would Derlwyn become a new Sub-Pedwar?

Time waiting for the Trimble to attain its accuracy and to log data can sometimes give one time to reflect upon life and its direction; today was one of those occasions.  It seems life can throw a good many fun moments and opportunities ones way as well as a heap of pain, hurt and sadness.  Some if not all is self-induced, I suppose it’s how one deals with the bundle that is life that gives eventual direction.  Right where was I, ahh yes, up on a hill with a Trimble!

Once I realised that the second critical bwlch option for Derlwyn was no more than an almost level bit of ground I wandered up to its summit, this consists of small rock outcrops, embedded and erratic boulders, today all were highlighted in afternoon sunshine.

I decided to take data from three rocks, the first where the spot height appears on the map, this proved to be a large erratic that had a convenient place for the Trimble to balance as its internal antenna was aligned with its highest point.  As data were gathered I retired a safe distance away and looked out on the higher peaks of Eryri.


The first of three surveys on the summit area of Derlwyn

The second option for the summit was a small embedded rock a few metres on the opposite side of a fence, I balanced the Trimble on another rock and placed it on the high point and waited, and waited, and waited.  It had performed well during the day’s surveys and attained its accuracy relatively quickly, this time it took 30 minutes to do so, I do not know why it took so long, but I’m now used to such occurrences and as long as the weather is favourable and no one disturbs its slow motion progress then I’m happier enough to wait, and today was no problem as I relaxed in the sun, occasionally jumping up to check on its progress.

The second of three surveys on the summit area of Derlwyn

Once it had gathered five minutes of data I strolled over to the far option for summit position, to the eye this looked distinctly lower, but as I was there I thought I’d gather data anyway.  This third placement was on the top of an impressive looking rock outcrop, again the rubberised bottom of the Trimble gave it enough friction to remain delicately perched in place, and again five minutes of data were collected.

The third of three surveys on the summit area of Derlwyn

I then followed the hill’s northerly ridge down from the summit area of Derlwyn across sun drenched grass and then veered west toward the bareness of path heading back to my car.  Another excellent walk with the edged colour of leafs and the chill of the proceeding night heralding the onset of autumn, a special time amongst the hills.


Survey Result:


Llechog

Summit Height:  720.0m (converted to OSGM15) (significant height revision)  
 
Summit Grid Reference:  SH 60613 56751

Bwlch Height:  692.1m (converted to OSGM15)

Bwlch Grid Reference:  SH 60557 56634

Drop:  28.0m  (Sub-Simm, Sub-Hewitt and 700m Sub-Twmpau status confirmed)

Dominance:  3.88%



Derlwyn

Summit Height:  416.4m (converted to OSGM15) 
  
Summit Grid Reference:  SH 58856 58610

Bwlch Height:  396.0m (converted to OSGM15)

Bwlch Grid Reference:  SH 59116 58477

Drop:  20.4m  (400m Sub-Pedwar addition confirmed)  

Dominance:  4.91%




For further details please consult the Trimble survey spreadsheet click {here}














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