Monday, 26 February 2018

Mapping Mountains – Trimble Surveys – Y Berwyn

26.01.18  Ffridd (SJ 038 121) and Mynydd Bach (SJ 051 123)

Mynydd Bach (SJ 051 123)

Dolanog is similar to many small communities in Wales as a quiet peacefulness pervades its realm, with this peaceful tranquillity also edging to the tops above the hamlet, which is nestled beside the Afon Efyrnwy (River Vyrnwy).  Today the river gushed eastward with grey waters, with this seemingly the only thing that stirred in Dolanog.


I hadn’t been out on the hill with Charlie for nine months and it was good to see him again, the hills we planned on visiting were ones that he had investigated a few weeks ago and having enjoyed them he wasn’t averse to re-visiting.

Having parked and walked across the old bridge we followed the paved road heading west which soon turned in to a vehicle track beside fields recently planted with trees, these new plantations continued on the northern side of the road and track all the way from the valley below toward the higher tops above.

The route to the hills

There was a slight freshness in the air with blue skies predominating above; both were welcome as the preceding days had been damp and grey.  The track avoids the first hill skirting it on its southern side, and heads toward the connecting bwlch between the two hills; here we heard a tractor chugging up from the south, smiling at Charlie I ran off to stop it.  Its occupant; Trefor Jones, farms from Maescelynog and it was his hill that we had just passed and which we planned on visiting after the higher westerly summit had been surveyed.  Trefor told us that the hill is named Mynydd Bach, with it being purchased from Neuadd-wen a number of years ago.  After thanking him for his time we carried on following the track toward Ffridd; the first and highest hill of the day.

Trefor Jones

The track led round the northerly part of the upper section of Ffridd and so we left it to walk to the summit, which is marked by a small, old cairn.  I set the Trimble on top of my rucksack, measured the offset between its internal antenna and the highest part of the hill and once the 0.1m accuracy level had been attained, pressed ‘Log’ and joined Charlie a few metres away.  During the five minute data collection we stood and admired the late morning’s light as sun and greying cloud added atmosphere to the scene.

Gathering data at the summit of Ffridd

As the Ordnance Survey Interactive Coverage Map hosted on the Geograph website gives a second top as 1m lower than the cairned summit, we headed over to it once the Trimble had gathered its allotted five minutes of data.

Gathering data at the 328m map heighted lower summit of Ffridd

Although this second top didn’t have the sweeping westerly views of the cairned summit it was crowned by an attractive small rock outcrop and as the Trimble quietly beeped away gathering its data, Charlie headed off to investigate the southerly outlying top which we both concluded was lower than where the Trimble was presently gathering its data.

Charlie admiring the view to the west

The 330.6m cairned summit of Ffridd from the 328.5m rock outcrop summit

Once the Trimble was packed away I joined Charlie and we then headed toward the inward vehicle track back toward the connecting bwlch between the two hills.  We’d assessed this from the track on our inward route and its southerly part was decidedly watery, enough so that even with wellies it would be a treacherous undertaking attempting to gather data from its depths, thankfully the ground slowly rose to the north and we followed the minor paved road that heads over this bwlch from south to north, to where dryer ground existed indicating that this was the higher part of the area of the bwlch. 

Looking east from the hills above Dolanog

With the Breiddin beyond

I took two data sets at this bwlch, both from its northern periphery, one amongst rough grass beside its bog and the other on the edge of the minor road, once data were stored we continued toward the summit of Mynydd Bach.

Gathering data at the critical bwlch of Mynydd Bach

As we ascended over closely cropped grass toward the summit of Mynydd Bach I occasionally turned around and looked back at the expanse of bog that makes up the connecting bwlch and even though eyesight alone is not ideal for judging either height difference or the upward / downward lay of land, the upward motion of this bwlch headed northward toward where the Trimble had been placed.

Thankfully the summit of Mynydd Bach is easily found as rising ground leads to a small embedded rock whose uppermost part just breaks the soil and grass, and with the area of the summit having no other discernible bump I aligned the Trimble with the highest part of the small rock and waited for the allotted five minute data set to be gathered.

Gathering data at the summit of Mynydd Bach

Before re-joining the vehicle track we headed further east to the end part of the upper ridge of Mynydd Bach, by now the predicted cloud build up had materialised and the sunlight that had given us striking colour had dulled.  The vehicle track led on to the upper part of paved road which took us down toward the Afon Efyrnwy and the car park in Dolanog.


Survey Result:


Summit Height:  330.6m (converted to OSGM15)

Summit Grid Reference:  SJ 03897 12140

Drop:  c 78m

Dominance:  23.48%

Summit Height:  324.9m (converted to OSGM15)

Summit Grid Reference:  SJ 05100 12325

Bwlch Height:  296.4m

Bwlch Grid Reference:  SJ 04661 12268

Drop:  28.5m (Sub-Trichant status confirmed)

Dominance:  8.79%

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