Friday, 6 January 2017

Mapping Mountains – Trimble Surveys – Mynydd Epynt

28.12.16  Mynydd Epynt (SN 961 464), Esgair Fawr (SN 927 433), Esgair Cerrig (SN 952 432), Twyn Rhyd Car (SN 960 422) and Drum Ddu (SN 979 447)

Esgair Fawr (SN 927 433)

As I clambered out of my car the chill breeze hit me and I shivered, and kept on doing so for the next ten minutes, but the view was sublime as a cloud enshrouded valley gave way to rising hill sides and the first throes of a rising sun edged the south-western horizon with a prospect of a good day ahead.

The cloud enshrouded valley

The rising sun

Banc y Cwm (SN 968 469)

I was meeting two friends for a walk over Mynydd Epynt, a land out of bounds for much of the year, but one whose hills are accessible over the Christmas period and we planned to take full advantage of the weather and the fact that the military do not frequent these hills at this time of year and visit as many Pedwarau as time would permit.

Once we had left a car next to the Drovers Arms we slowly made our way back on the frost encrusted road to the high point where a track gave access to Mynydd Epynt, which according to the map is the highest point of the hill range.

It was good to be on this hill range again as I’d only been on the land that is out of bounds once before, and that was a number of years ago on four of the north-easterly hills with two being within the Danger Area.

As we reached the summit of the first hill a Landrover pulled up and an enquiring farmer wondered if we knew where we were and more importantly where we were going, we chatted with the farmer and enquired about place-names whilst I set the Trimble up beside the small concrete pillar that marks the high point of the hill and proceeded to gather five minutes of data.

Gathering data at the summit of Mynydd Epynt

It was a stunning morning as the sun had now burst through any low lying cloud and the blue sky heralded a good day on the hill.  Our next hill was almost 5km south-westward, and the majority of the route was on the paved road that follows the northern escarpment of Mynydd Epynt and which now forms a part of the Epynt Way; this long distance path was created by the Ministry of Defence in 2004 and gives the public welcome access to a part of this hill range.

The road was a ribbon of white and stretched out toward the square blocked conifer plantations near the summit of Esgair Fawr, our second hill of the day.  To our north-west the valley was still submerged in mist and remained so all day, a testament to an ethereal other worldliness embedded in dulled cold.

The paved road following the northern escarpment of Mynydd Epynt

The mist enshrouded north-western valley

As we neared the trig pillar atop Esgair Fawr I knew I was in for a long day as a combination of cough, head cold, wonky knee, hip and neck, too much food intake over Christmas and lack of mountain fitness due to not being on the hill for a number of weeks meant that my two friends spent most of the day being patient, and having to wait for the sloth like creature that followed in their wake.

At least Trimbling each summit gave me a ten minute rest, but once data were gathered from the ground beside the trig pillar atop Esgair Fawr we plodded back across the upper hill onto the paved road and retraced our route to a prominent obelisk where we followed a track to the south-east that took us down to the connecting bwlch with our third hill of the day; Esgair Cerrig, we were now in the impact zone and dotted around us were discarded ordnance, but as long as you paid attention there doesn’t seem to be a major problem with walking these hills.

Gathering data at the summit of Esgair Fawr

Over the last few weeks, a colleague of mine had examined LIDAR data which has resulted in many reclassifications of hills, he had produced results for many of the summits and bylchau around the Epynt, and so I had decided to concentrate the Trimble surveys on the summits, and any bylchau where LIDAR data did not cover, and the next bwlch was one such example.

Gathering data at the critical bwlch of Esgair Cerrig

As the Trimble gathered data we had a glance at a wooden structure comprising two heads which was no doubt used for target practice, it felt odd to see something like this on a hill, but the ascent toward the summit of Esgair Cerrig brought home the nature of what happens on these hills as shell casings and various bits of ordnance were scattered amongst the moorland surroundings, but above all it was the bomb craters that stood out as one after another scattered the hillside, a place not to venture unless free of its usual goings on.

Target practice

The examination of LIDAR data had pinpointed the summit of Esgair Cerrig to be in the south-western part of its 450m uppermost map ring contour and not on the north-easterly part where the 456m spot height appears on current Ordnance Survey maps.  On our way to the high point we passed a rusting old tank and I set the Trimble up beside the debris of a bomb crater, I suppose there’s a first time for anything when out on the hill.

One of many bomb craters on Esgair Cerrig

Abandoned tank

Discarded ordnance

Gathering data at the summit of Esgair Cerrig

By now my physical strength was suffering, and after packing the Trimble away we headed toward Twyn Rhyd Car, our fourth hill of the day, this lay southward on the same ridge that descends from near to the obelisk on the northern escarpment, and a few sheep tracks headed toward its connecting bwlch, we looked ahead wondering what one to take and as an abandoned tank was on the ridge ahead we decided to ‘head for the tank’, another comment that is rarely heard when on the hill, this made me smile and kept me going as my two colleagues slowly pulled ahead of me.

'Head for the tank'

By the time I reached the summit of Twyn Rhyd Car I was slobbered and felt like curling up and falling asleep, however its summit needed Trimbling and there was still a long way to go to get back to the car at the Drover’s Arms.

Gathering data at the summit of Twyn Rhyd Car

We had one hill left to visit; Drum Ddu, and its summit lay distant, shimmering on the horizon a long way away, I knew I would suffer, and I did, but the valley we descended into was a pleasure to visit, it proved a quiet place with a prominent forgotten farm house named Byllfa-uchaf on the map, and we used this to aim for.  I tried to appreciate my surroundings, and although I did, my head was down and my body trance like as I plodded slowly after two ever smaller figures who had found an excellent narrow path on a raised earthen embankment that bi-passed much of the bog and tussocks.  After crossing a stream I lay on the opposing hillside and looked down the river valley as it extended south toward the grey silhouetted profile of the Beacons.  

Drum Ddu looked a long way away

The river valley extending south toward the Brecon Beacons

The wilds of the Epynt - a beautiful land

All too soon we were away hunting out a path that led up toward the summit of Drum Ddu, this uphill seemed never ending and my reserves of energy were now near empty and I had to stop and regain a semblance of dignity and breath even on the relatively flat sections, however the old adage of just take one step at a time is apt in such situations, even when feeling in a mess on the hill, and eventually I dragged my body to the trig pillar at the summit of Drum Ddu, and once five minutes of data were gathered from the highest ground at its base I became quite chatty and followed my two friends down the track to the awaiting car.

Gathering data at the summit of Drum Ddu

The inner realm of the Sennybridge Training Area is one to visit when conditions are good and the military are not there.  I would not recommend visiting when the weather is inclement and the thought of doing so when live-firing is taking place would be utterly foolhardy.  The whole of the Epynt deserves exploration and it is a shame that such upland beauty is now out of bounds for much of the year.  

Survey Result:

Summit Height:  475.7m (converted to OSGM15) (significant height revision)
Summit Grid Reference:  SN 96124 46428

Bwlch Height:  c 278m (interpolation)

Bwlch Grid Reference:  SN 84063 43279 (interpolation)

Drop:  c 198

Dominance:  41.62%


Summit Height:  475.3m (converted to OSGM15)

Summit Grid Reference:  SN 92746 43357

Bwlch Height:  439.2m (LIDAR)

Bwlch Grid Reference:  SN 95188 45390 (LIDAR)

Drop:  36.1m (Trimble summit and LIDAR bwlch)

Dominance:  7.59% (Trimble summit and LIDAR bwlch)


Summit Height:  456.4m (converted to OSGM15)

Summit Grid Reference:  SN 95224 43297 (summit relocation confirmed)

Bwlch Height:  420.8m (converted to OSGM15)

Bwlch Grid Reference:  SN 95137 44068

Drop:  35.6m (Pedwar status confirmed)

Dominance:  7.81%


Twyn Rhyd Car

Summit Height:  453.5m (converted to OSGM15)

Summit Grid Reference:  SN 96038 42263

Bwlch Height:  419.0m (LIDAR)

Bwlch Grid Reference:  SN 95698 42538 (LIDAR)

Drop:  34.5m (Trimble summit and LIDAR bwlch)

Dominance:  7.60% (Trimble summit and LIDAR bwlch)


Drum Ddu

Summit Height:  473.9m (converted to OSGM15)

Summit Grid Reference:  SN 97932 44744

Drop:  36m

Dominance:  7.60% 


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