Friday 19 June 2015

Mapping Mountains – Trimble Surveys – Y Berwyn


07.06.15  Foel Wylfa (SJ 192 331), Gwastad Mawr (SJ 210 349), Foel Rhiwlas (SJ 200 327), Craig yr Hwch (SJ 213 323), Belan (SJ 222 324), Mynydd Lledrod (SJ 216 309) and Coed y Bwlch (SJ 224 304)    

Foel Rhiwlas (SJ 200 327)
Having met Aled in Rhydycroesau we left his van diagonally opposite a Chapel a mile up the narrow lane at SJ 232 311o and continued west toward the higher Berwyn and parked my car on the grass verge next to a gate at approximately SJ 186 331.  Before parking my car we investigated the bwlch for Foel Rhiwlas which is positioned close to the cross roads of narrow lanes a few hundred metres down the road from where I eventually parked.  Once I had gathered data at this bwlch I rejoined Aled who had waited beside the car, he had watched a chaffinch fly from the hedgerow and showed me its nest, a marvellous, intricate and delicately manufactured thing of beauty.  We then proceeded up the lane and parked the car.

Gathering data at the critical bwlch of Foel Rhiwlas
Chaffinch's nest - a delicate thing of beauty
The day’s forecast was ideal with sunshine and a light breeze, the day’s hills looked good and we had planned to visit six Pedwarau with an option to cut the walk short after the first four.  I’d visited these hills once before in July 2003 and had memories of using a centrally positioned track to visit many of the hills.  I’d been fortunate with my previous visit as the sky had then shone blue and the hills were quiet, a very similar day to today.

We left the car and used the first of many gates to gain access onto the slopes of Foel Wylfa, the first of our planned six hills, as we joined its westerly ridge fence for the last few metres to its summit the patches of cloud cast shadowed, attractive patterns on its green higher slopes with splashes of gorse adding intensity to the colour of the hill.

The upper section of Foel Wylfa
Foel Wylfa has two high points, as the first was being Trimbled I looked out on the beautiful landscape below with the cultivated fields leading to the darkened profile of the high Berwyn ridge.  Across the intervening valleys rose the hill which is currently named as Gyrn Moelfre on Ordnance Survey maps, this dominated the immediate skyline with its eloquent flattish eastern ridge leading to its slightly pointed summit

Specks of white on a green landscape
Gathering data from the first high point on Foel Wylfa with the high Berwyn beyond
The most northerly of the two high points of Foel Wylfa has a small fenced enclosure on it, in the enclosure is a memorial stone to Irene May Louisa Hill and Charles Henry Hill.  Although this spot was a fitting place for two loved ones to be remembered the enclosure was unnecessarily obtrusive and the vegetation inside now overgrown.

Gathering data from the summit of Foel Wylfa with the fenced enclosure on left of photo
Memorial stone to Irene May Louisa Hill and Charles Henry Hill
Once each high point had been Trimbled we continued down toward this hill’s connecting bwlch with Pen y Gwely, which is a Sub-Pedwar and whose summit and bwlch had been recently surveyed in the company of Mark on an evening walk a few weeks ago. 

The critical bwlch for Foel Wylfa was situated in a field of long swaying grass which moved in sync swathes as the morning’s breeze blew across the hills.  Aled remained on the track beside the bwlch and directed me toward where the critical bwlch lay, I then spent a few minutes creating my first crop circle, once my artistic design was complete I placed the Trimble down and set it to collect data.

My first attempt at creating a crop circle
As the Trimble gathered data I walked back toward the fence adjacent to the track we had reached, this track would give us access to the next three hills and eventually marches down to the area around the Pen y Gwely Reservoir which we planned on visiting later in the day.  Before packing the Trimble away I took a series of photographs as the sun and cloud cast light and shade of my crop circle.  Wondering what the farmer would think of this unusual pattern that had appeared in his field I rejoined Aled on the track.

Gathering data at the critical bwlch of Foel Wylfa
Our next hill was Foel Rhiwlas, the highest of the day, before visiting its summit we collected data from the bwlch leading upto its high point, this is the critical bwlch of Gwastad Mawr, whose summit was surveyed on the previously mentioned evening walk with Mark a few weeks ago.

Foel Rhiwlas
Foel Rhiwlas also has two high points that vie for the summit position, with a third lower top further south.  The two higher points were Trimbled with one having a small flat cairn on it.  As the Trimble gathered its data we sat and had a bite to eat overlooking the southern lower summit as its bulk smoothly descended to the valley below.

The lower southerly top of Foel Rhiwlas
Having packed the Trimble away we backtracked back to the track, (that sounds rather melodic) and continued east toward our next bwlch which was positioned in a reed infested patch of land, once Trimbled we continued up to the summit of Craig yr Hwch.

Gathering data at the critical bwlch of Craig yr Hwch
As the Trimble gathered data on the high point of Craig yr Hwch we walked toward a fence junction and looked out toward the hills, again light and shade enhanced the land with deep shadows adding depth to the landscape.  The day was proving very enjoyable and unrushed, and with a mound of hilly related subjects for Aled and I to discuss it was also proving extremely productive for future plans as well as for bagging and surveying hills.

The view south-west from the fence junction
Down we went back onto the track, which now led into a conifer plantation, ahead lay the rounded profile and forested westerly flank of Belan, which is listed as a Pedwar due to a 30.2m basic levelling survey that I had conducted during my walk in July 2003.

The forested western flank of Belan
The summit of Belan was relatively easy to pinpoint and the customary five minutes of Trimble data was gathered from it, we then retraced our steps back to its connecting bwlch and proceeded to take two data sets, one from its pastured land which we both agreed looked to be where its critical bwlch lay, and the second data set from beside an earthen track which was on the course of another valley to valley direction passing over the hills.

Gathering data from the summit of Belan
During the day we had heard a number of trail bikes off in the distance where a large group of vehicles were parked on a hillside.  As the Trimble gathered data next to the earthen track a number of bikes now whizzed down the track past us and the Trimble.  I chatted to one of the riders as he pulled up to open a gate, they were taking part in an enduro meet and he kindly said that he’s let his fellow competitors know that a small yellow and black piece of surveying equipment was positioned next to this tack and to try their utmost not to squash it when they hurtled past.

Gathering data with the Trimble at the bwlch of Belan
And hoping the trail bikes would not run it over
By now the afternoon had warmed up, and the breeze when it blew was a welcoming relief from the warmth of the day.  We left the bwlch of Belan and descended on another track toward the edge of the conifer plantation and then through it on a lovely track as it headed down to a footbridge over the Nant Penygwely.

On the opposite side of the stream the main track continued past the Pen y Gwely Reservoir which was built in 1889 and feeds water to the inhabitants of Oswestry.  This part of the walk was rather magical as it was similar to entering an estate with landscaped gardens and lakes, and all under a succulent blue sky.

Our route down to the Pen y Gwely Reservoir passed a number of beautiful trees
The Pen y Gwely Reservoir
Ducks doing what ducks do
The forested slopes of Belan overlooking the Pen y Gwely Reservoir
Beyond the reservoir our track bi-passed the direct route toward our next bwlch and continued down toward Tynyfron before doubling back onto the narrow lane and upto its high point.  As we walked up the lane the hedgerow was ablaze with colour and a small speckled yellow moth darted between the flowers, we followed it for a while and spotted another one and watched as they flitted to and fro.

When we reached the top of the lane we met Huw Evans who was outside playing with his children, we chatted for a number of minutes, Huw is a contractor and grew up locally, he had reverted the name of his bungalow back to its original Welsh name from one that wasn’t really in keeping with the country’s language or culture.  We happily passed a number of minutes talking about the local hills and checking on their names, and getting one or two contacts for future research.

The top of the narrow lane beside Huw’s bungalow was the critical bwlch for Coed y Bwlch, which was our planned sixth hill of the day.  The position of this critical bwlch lay beside the road on a gravelled area, it was duly Trimbled and we continued up toward our next hill, with permission to visit its summit having been asked by us and given by Huw.

Gathering data at the critical bwlch of Coed y Bwlch
The walk upto the summit of Mynydd Lledrod proved a tranquil, albeit slow affair with views over to our first two hills of the day; Foel Wylfa and Foel Rhiwlas.  The Trimble was placed on two points at the summit, both on an old earthen embankment which looked part of the hill and we estimated a measurement offset to the natural ground below.

Foel Rhiwlas from the ascent of Mynydd Lledrod
Gathering data from the summit of Mynydd Lledrod with Coed y Bwlch in the background
Leaving the summit of Mynydd Lledrod behind us, we followed its easterly ridge down to the connecting bwlch with Coed y Bwlch.  This last hill of the day rose up in the late afternoon sunshine with its wooded summit of Scots Pine and Larch looking resplendent, I can remember my previous visit to this hill and how pleasant its top was as it felt dissimilar to the other adjacent hills with its summit scattered with beautifully shaped trees.

Heading to the summit of Coed y Bwlch
The ascent proved wearisome as I opted for the direct approach whilst Aled found a green track that gained height toward the summit.  Soon we were at the high point which is positioned directly under a large Scots Pine.  As the Trimble ebbed down to the 0.1m accuracy before data can be logged we sat and chatted and had another bite to eat.  Thankfully the Trimble attained the 0.1m accuracy relatively quickly considering where it was positioned and as it gathered its summit data we relaxed in the sun.

The Scots Pine at the summit of Coed y Bwlch
Gathering data from the summit of Coed y Bwlch
Only one survey was left and that was back at the base of Coed y Bwlch at the connecting bwlch with Mynydd Lledrod, this proved to be close to a gate and in a field.  Once the survey was completed and the Trimble packed away we sauntered down the lane back toward Aled’s van.

The lane led down to a track which we followed for a short distance before leaving it to join a path through a field, the last few metres proved fun as the path took us through an overgrown and enclosed nettle infested patch of land, not something to encounter when wearing shorts at the end of a day’s walk.

Summer flowers
Tackling the nettles
As Aled slowly stomped down the nettles I picked a balancing route through them as best I could and a few minutes later we were back beside the Chapel and Aled’s van.  The walk and 17 surveys had taken 8hr 30min and we rounded off the day with a meal in a pub in Glyn Ceiriog.

  

Survey Result:


Foel Wylfa

Summit Height:  453.5m (converted to OSGM15) 

Summit Grid Reference:  SJ 19219 33166

Bwlch Height:  393.3m (converted to OSGM15)

Bwlch Grid Reference:  SJ 19653 33261

Drop:  60.2m

Dominance:  13.27%






Summit Height:  448.9m (converted to OSGM15)

Summit Grid Reference:  SJ 21055 34971

Bwlch Height:  413.5m (LIDAR)

Bwlch Grid Reference:  SJ 20287 32903 (LIDAR)

Drop:  35.3m (Trimble summit and LIDAR bwlch)

Dominance:  7.87% (Trimble summit and LIDAR bwlch)






Foel Rhiwlas

Summit Height:  455.3m (converted to OSGM15)

Summit Grid Reference:  SJ 20030 32735

Bwlch Height:  361.8m (LIDAR)

Bwlch Grid Reference:  SJ 18357 32923 (LIDAR)

Drop:  93.5m (Trimble summit and LIDAR bwlch)

Dominance:  20.54% (Trimble summit and LIDAR bwlch)





Craig yr Hwch

Summit Height:  447.3m (converted to OSGM15)

Summit Grid Reference:  SJ 21357 32357

Bwlch Height:  387.5m (converted to OSGM15) 

Bwlch Grid Reference:  SJ 21396 32830

Drop:  59.9m

Dominance:  13.38%






Summit Height:  411.2m (converted to OSGM15)

Summit Grid Reference:  SJ 22211 32401

Bwlch Height:  381.2m (converted to OSGM15)

Bwlch Grid Reference:  SJ 22498 32561

Drop:  30.0m (Pedwar status retained)

Dominance:  7.30%
  




Mynydd Lledrod

Summit Height:  401.5m (converted to OSGM15) (Pedwar status confirmed)

Summit Grid Reference:  SJ 21611 30923

Bwlch Height:  358.2m (converted to OSGM15)

Bwlch Grid Reference:  SJ 22471 30740

Drop:  43.3m

Dominance:  10.78%





Summit Height:  414.0m (average of two surveys, 2nd survey 20.07.16 and converted to OSGM15)

Summit Grid Reference:  SJ 22416 30481

Bwlch Height:  327.9m (converted to OSGM15)

Bwlch Grid Reference:  SJ 22249 31686

Drop:  86.1m (average of two summit surveys, 2nd survey 20.07.16)

Dominance:  20.80%





For the summit survey of Gwastad Mawr

For the 2nd Trimble survey of Coed y Bwlch

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








1 comment:

summitsup said...

Did you find the earthquake monitoring station somewhere near the top of Foel Wylfa, Myrddyn? It was snow covered when I visited. My blog for 29 December 2014 at http://summitsup.blogspot.co.uk/2014/12/foel-wylfa-craig-yr-hwch.html has a link to a bit more info.