Wednesday 29 May 2019

Mapping Mountains – Trimble Surveys – Elenydd


27.02.19  Cefn Cwm Coel (SN 891 647), Craig Fawr (SN 879 638) and Pen Garn Ddu (SN 891 628 [bwlch only])

Cefn Cwm Coel (SN 891 647)

The hills of the Elenydd are some of the most tranquil, and yet also some of the roughest anywhere in the country.  They are in the main open hills, with only a few fences crossing their ridges, and consist of rough grassland which in summer can be energy sapping and soul destroying.  However, in late winter / early spring when Sky Larks sing overhead and a cooling breeze sweeps across their desolate land there are few other places I would rather be.

Today was forecast to be the last day of the unseasonably warm weather and therefore with clear conditions I decided to visit the hills between the Claerwen and Garreg Ddu / Caban Coch reservoirs to the south-west of Rhaeadr Gwy (Rhayader).

As I set off on the track leading toward the farm of Henfron blue sky radiated from above casting early morning colour with the sun glinting through the trees that sprung up beside the waters of the Garreg Ddu Reservoir.  The track led through old deciduous woodland and gave to a leisurely pace. 

Glinting light

The bridge spanning the Garreg Ddu and Caban Coch reservoirs

The bridge spanning the waters between the Garreg Ddu and Caban Coch reservoirs merged grey in the background giving an ethereal feel to the land.  Although the track was shaded with dappled light the sun and blue sky heralded a warm day ahead on the hill.

The track leading to Henfron farm

As I gained height past the farm of Henfron the wilderness of the Elenydd opened up with its bleached moor and rough grassland.  Ahead lay the summit of Cefn Cwm Coel which had been reclassified to 500m Sub-Uchaf status in February 2017 with 14m of drop based on the 489.6m LIDAR bwlch data analysed by Aled and the 504m Ordnance Survey summit spot height.  I wanted to take summit and bwlch data with the Trimble to ascertain this hill’s accurate drop value.

Beyond the last gate I followed vehicle tracks on the moor and only left these when the summit ridge came in to view.  Once off the vehicle track the underfoot conditions became rough with grassed tussocks and heather the order of the day.  Surrounding me the land shone a tinged subtle and bleached yellow, a marvellous sight.

I spent 40 minutes on the summit of Cefn Cwm Coel and took data sets from four potential summit positions.  During this I looked out on my next objective; this hill’s connecting bwlch to Craig Dyfnant, and it looked a wild inhospitable place consisting of an extremely large bog.

One of four data sets gathered on the summit area of Cefn Cwm Coel

The openness of these hills can take time to adjust to, as there are few features for the eye to follow, just rising land to more open hills and rounded grassed ridges leading in to the distance.  Once I had packed the survey equipment away I tried to follow a sheep track through the tussocks down to the connecting bwlch.  By now my mind was adjusting to the landscape with its openness a thing of beauty however rough the underfoot conditions.

Nearing the bwlch the land turned from bleached tussock to dulled brown heather, and the grid reference produced for the critical point from Aled’s LIDAR analysis led me through a never ending land of heather and bog, which today after the warm weather of late was thankfully relatively dry.

I stood and enjoyed my surroundings as the Trimble gathered its customary five minutes of data.  The bog only ended as the land rose toward the eastern slopes of Craig Dyfnant, and I wondered where my best route lay toward the next survey point; the bwlch of Craig Fawr.  Once the Trimble had gathered its allotted data I set off on a direct course toward the next bwlch and soon regretted my decision as the underfoot conditions proved extremely rough, soon however I found another sheep track that thankfully led me toward another relatively dry bog.

Gathering data at the critical bwlch of Cefn Cwm Coel

This next bwlch proved to be situated in another stunning place, with a slender water course indicating the slow ebb of the ups and downs.  I took two data sets and after activating the equipment to log data I marched off across the bog so as not to get in the way of satellite reception and straight in front of me a large bird silently took flight, I had a glimpse of a rounded head as it flew away to nestle back on the moor.  I had disturbed a Short-eared Owl.

Gathering data at one of two positions surveyed for the critical bwlch of Craig Fawr

It proved a slow plod up to the summit of Craig Fawr which has a number of contenders for its summit position.  I took data from three points, during which I looked out on the blued waters of the Claerwen Reservoir as the first signs of delicate westerly mist slowly rolled in.

The Claerwen Reservoir

Once all points judged to be worthy of summit contention had been surveyed I packed the Trimble away and headed east toward a slight rise overlooking steepening ground.  I’d overheated on my ascent but had welcomed the morning’s cooling breeze as height was gained, but now I needed to convert my walking trousers to shorts and take my spring fleece off as it was so warm, I cannot remember having to do this on the hills in February before.

Gathering data at the summit of Craig Fawr

I did wonder if I should continue to Pen Garn Ddu and Gurnos but decided that time and the warmth of the day dictated that it was time to descend, but not before one last survey of the critical bwlch of Pen Garn Ddu.

This was again placed in a large bog that was thankfully relatively dry.  Its yellowed tinge almost glowed in the afternoon sunlight.  I sat during data collection and let my mind wander, as I also did once the equipment was packed away and I walked the few metres back toward a gate.

Gathering data at the critical bwlch of Pen Garn Ddu

It had proved a beautiful day on these hills, and again I stopped by the next gate entrance and rested in the warmth of the day.  This gave access on to a track which led through the conifer plantation to my awaiting car.

Having followed the forest track down I lingered beside the road bridge spanning the Garreg Ddu and Caban Coch reservoirs taking a series of photos and talking with a number of people who were out enjoying the warmth of the day.

The Garreg Ddu Reservoir and Valve Tower

The subtle greys of the morning against this bridge had been replaced with succulent colour and dappled reflections.  I was in no rush and savoured the time here.  Just looking and enjoying.  But as with everything, there comes a time to leave.  It had been a good day on the hill with the Elenydd beckoning for another visit shortly.           

      

Survey Result:


Cefn Cwm Coel

Summit Height:  503.0m (converted to OSGM15)

Summit Grid Reference:  SN 89142 64733

Bwlch Height:  489.6m (converted to OSGM15)

Bwlch Grid Reference:  SN 88436 65372

Drop:  13.4m (500m Sub-Uchaf deletion)

Dominance:  2.66%




Craig Fawr

Summit Height:  517.9m (converted to OSGM15)

Summit Grid Reference:  SN 87939 63846

Bwlch Height:  475.7m (converted to OSGM15)

Bwlch Grid Reference:  SN 88241 64748

Drop:  42.1m

Dominance:  8.14%




Pen Garn Ddu

Summit Height:  466.5m (LIDAR)

Summit Grid Reference:  SN 89125 62814

Bwlch Height:  415.2m (converted to OSGM15)

Bwlch Grid Reference:  SN 88854 63617

Drop:  51.3m (LIDAR summit and Trimble bwlch)

Dominance:  11.00% (LIDAR summit and Trimble bwlch)






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