Thursday, 25 February 2021

Mapping Mountains – Trimble Surveys – Y Berwyn

 

26.11.20  Moel yr Henfaes (SJ 077 385), Y Drum (SJ 082 378), Pt. 581.7m (SJ 086 373) and Cefn Dylif (SJ 089 369) 

Y Drum (SJ 082 378)

For many years it was as if I was walking with blinkers on, as I concentrated on the higher 2,000ft mountains and rarely ventured to any hill that was lower.  It was the listing of the Deweys that opened my eyes to the lower hills, closely followed by the remaining Twmpau.  And two hills on today’s walk show how blinkered my vision was, as the first hill; Moel yr Henfaes I had only visited once before in August 2000, whilst the last hill; Cefn Dylif I had visited on 21 occasions.  Both hills are on the same ridge, with the former at its north-westerly end and the latter joining the main Berwyn ridge.  But the difference in totals is purely down to height. 

I was joining Mark and Aled for this walk and the arrangements to meet and route and hills to visit were quickly organised the preceding evening.  We met in Cynwyd and took two cars to the end of a steep minor road and parked beside the farm buildings at Rhos-y-maerdy.  This was at 350m, which helped somewhat. 

The way to the hill

I set off a few minutes before the others and made my way up the track that continues from the end of the paved road.  Conditions were beautiful with the remnants of mist still in the valley below and the higher Berwyn tops clear with autumnal blue sky above, whilst further to the north and west many of the higher tops were cloaked in a blanket of grey. 

The view west with mist in the valley and a grey murk over the higher tops

Breaking away from the track a field led up beside the Nant y Cwm toward the bwlch between Moel yr Henfaes and Y Drum, in time this would be surveyed, but our first objective was the summit of Moel yr Henfaes.  I heard Mark and Aled before I could see them, with their voices echoing against the stillness of the morning.  By the time they emerged on to the field below I was now immersed in heather, making slow, rough progress ever upward. 

An occasional sheep path amongst the heather helped, but in the main it was rough and pathless.  Bit by bit height was gained and I eventually reached the ridge and swung left up toward the summit.  Within a minute or so of arriving on top I was joined by Mark and Aled. 

As the Trimble gathered summit data we sat and stood close to the cairn in the morning sunshine looking out across a myriad of hills, some clear, others still cloaked in grey, but all inviting. 

Gathering data at the summit of Moel yr Henfaes

It was only a short distance back toward the connecting bwlch which is the critical one for the next hill on the ridge; Y Drum.  This was in a sea of tussock grass and heather and as I stood knee deep in the stuff Mark used his hand-held GPS to zero in to where the 551m spot height appears on the ground.  The whole area was awash with large tussocks and this was our best way to approximate where the bwlch lay.  Before setting the Trimble up, I assessed the lay of land and as I positioned the equipment on top of my rucksack, Mark and Aled headed toward the summit of Y Drum. 

Gathering data at the bwlch of Y Drum

Once data were gathered and stored I closed the equipment down, packed it away and stumbled my way to a part of the hill where the heather had been cut, this at least enabled easier underfoot conditions, and the temptation of a grazed and closely cropped grassy field was not too far away.  This I reached and within a couple of minutes I joined the others at the summit. 

Moel yr Henfaes (SJ 077 385)

The summit of Y Drum is attractive and consists of a small rocky knoll.  After setting the Trimble up to gather data we each sat, socially distanced on a rocky rib that extended out from the summit area.  A few minutes later it was time to head off again, this time down to the bwlch that is the critical one for Moel yr Henfaes. 

Gathering data at the summit of Y Drum

I headed off before the others and had the Trimble set up gathering data as they waved and headed past me up toward the summit of a 582m map heighted hill that had recently been promoted to Sub-Uchaf status.  The proceeding summit and bwlch survey will confirm its status one way or the other. 

Gathering data at the bwlch of Moel yr Henfaes

Its summit was beside the ridge fence overlooking a steep drop down to its bwlch.  By the time I arrived at its high point, Mark and Aled had assessed the lay of the land and chosen the place for Trimble placement.  As the equipment gathered summit data, Aled headed down to assess the bwlch.  Once data were gathered and stored I joined him, whilst Mark headed off and waited for us just beyond the bwlch. 

Mark and Aled heading to the summit of what used to be a 500m Sub-Uchaf

We took two data sets from the area of the bwlch, each on the hill to hill traverse.  The ground above and to our north was steep, and whilst the Trimble gathered its sixth and seventh data set of the day we debated whether this hill would retain its sub status. 

Only one hill remained to survey and after closing the equipment down I followed Mark and Aled up a vehicle track on the moor toward a fence and then across it to the rocky rib and cairn that make up the summit of Cefn Dylif.  The last time I had visited this summit was in August 2007, a lot has changed in my life since then, some good, some not so good, and although it is clichéd to say; the allure of the hills remain as a constant. 

Gathering data at the summit of Cefn Dylif

After the summit was surveyed we headed down to the bwlch which has the continuation of our inward track crossing it, before it continues down following the course of the Nant Rhydwilym to the Afon Ceiriog.  It was easy to pinpoint the critical point and as the Trimble was set up Mark and Aled went to find the book beside the memorial to the Wayfarer. 

Gathering data at the bwlch of Cefn Dylif

Many years ago a form of garage stood at this bwlch, its roof finally gave up and collapsed and now any lingering remnants have been removed.  It leaves this part of the Berwyn garage free, and all the better for it. 

The Wayfarers Memorial

The bwlch survey was the ninth data set of the day and once safely stored I closed the Trimble down, took a few photos and packed it away and we headed down the track back to the awaiting cars.  It had been another good day on the hill. 

 

Survey Result: 

 

Moel yr Henfaes  

Summit Height:  584.5m (converted to OSGM15)

Summit Grid Reference:  SJ 07755 38589

Bwlch Height:  547.4m (converted to OSGM15)

Bwlch Grid Reference:  SJ 08418 37600

Drop:  37.1m

Dominance:  6.34%

 

 

Y Drum  

Summit Height:  579.1m (converted to OSGM15)

Summit Grid Reference:  SJ 08247 37893

Bwlch Height:  549.0m (converted to OSGM15)

Bwlch Grid Reference:  SJ 08003 38256

Drop:  30.1m (500m Sub-Twmpau reclassified to 500m Twmpau) (Dewey addition)

Dominance:  5.20%

 

 

Pt. 581.7m  

Summit Height:  581.7m (converted to OSGM15)

Summit Grid Reference:  SJ 08664 37360

Bwlch Height:  568.7m (converted to OSGM15)

Bwlch Grid Reference:  SJ 08659 37320

Drop:  13.0m (500m Sub-Uchaf deletion)

Dominance:  2.23%

 

 

Cefn Dylif  

Summit Height:  618.3m (converted to OSGM15) (significant height revision)

Summit Grid Reference:  SJ 08943 36942

Bwlch Height:  581.3m (converted to OSGM15)

Bwlch Grid Reference:  SJ 09068 36590

Drop:  37.0m

Dominance:  5.99%

 

 

For further details please consult the Trimble Survey Spreadsheet

 

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