Saturday, 7 May 2016

Mapping Mountains – Trimble Surveys – Y Berwyn


04.05.16  Craig Garth Bwlch (SJ 018 181) 

Craig Garth Bwlch (SJ 018 181)

I’d visited Craig Garth Bwlch once before in May 2004 and stood on the closely cropped pastured summit and looked over to the blue expanse of Llyn Efyrnwy (Lake Vyrnwy).  From this vantage point the lake is a lagoon stretching toward the wild summits of the southern Berwyn.

The summit I’d visited on that day in 2004 is given a 394m spot height on Ordnance Survey maps, it was only after the Ordnance Survey enlarged mapping on the Geograph website became available that the adjacent south-westerly summit that is immersed in a conifer plantation was given a spot height of 399m.  Ever since I’d wanted to re-visit and try and get to the now known highest point of the hill.

I parked close to a red telephone kiosk on the minor lane to the south-west of the summit and walked up the lane to where the start of a forest track headed into the trees.  Freshness predominated with greens of spring shooting out from hedgerows as blue sky shone from above.

The hill is all but obscured when approaching from this direction as the near trees tried to overwhelm the track.  But to my left the steepening slope foretold a battle through the trees.  I planned on visiting the pastured grassy summit first and gather two data sets, with both positions given a 394m spot height on the enlarged Geograph map, it was only after these initial surveys that I planned on getting to grips with the trees, with the prospect of a steep and bramble infested ascent according to a log on Hill Bagging.

I followed the track until it met the grassy slopes of the hill and walked up the steep southerly slopes and emerged just east of the 394m pastured summit.  Within a few minutes I was on top and the view to my north-west bounced out in front of me with the expansive waters of Llyn Efyrnwy (Lake Vyrnwy) leading my eye to the wilderness beyond.  The hills surrounding this lake are some of the least visited in the country and for good reason, as they are wild affairs where heather and bog predominate.  However, although this view kept my gaze, it was the one to my south-west that I found most interesting, as beyond the second 394m map heighted pastoral rise there was a lump of a summit that except for the remains of felled trees was free of conifers.  I peered toward it and quickly examined my map to try and judge the distance between where I stood compared to the forest boundary fence and the 399m map heighted summit, a smile came to my face as the summit of the hill was free of conifers and looked relatively easy to get to.  The added bonus was that it could be easily Trimbled and with a 399m map height it meant that with one added metre it would be promoted to the ranks of Y Pedwarau.

Llyn Efyrnwy (Lake Vyrnwy)

After gathering data at the two positions where the 394m map spot heights appear on the ground, I sauntered over to the forest boundary fence and stepped over it on to the detritus of land overtaken by conifer plantation with the remains of branches and tree stumps interspersed amongst steepening ground.  As felled forestry goes it proved a doddle to walk to the high point of the hill, my worry was that there might be another high point beyond and still immersed in those wicked conifers, thankfully there was none.

Gathering data at the most north-easterly of the two 394m map heighted tops (392.9m [converted to OSGM15] Trimble survey) with the deforested high point of the hill in the background

Gathering data at the second of the 394m map heighted tops (392.4m [converted to OSGM15] Trimble survey) with the deforested summit of the hill in the background

Contrast between a pastured hillside and the ravages of deforested conifer plantation

After a few minutes I’d assessed the ground and chosen my preferred spot for where I judged the summit of the hill to be positioned.  I placed the Trimble on top of my rucksack to elevate it above the multitude of dead branches strewn around the summit and once the 0.1m accuracy level had been attained I pressed ‘Log’ and scampered through the detritus to stand a safe distance from the equipment.

My rucksack marks the high point of Craig Garth Bwlch

Gathering data from the summit of Craig Garth Bwlch with the lower pastured summit in the background

Whilst gathering two five minute data sets from the same point I stood and stared at the block of the Aran which dominate the skyline above the lake, these hills are wonderful and ones that I have not visited for far too long.

The high Aran

After packing the equipment away I clambered back through the remains of tree branches and retraced my inward route back to the car.  On the way my mind wandered and my body soaked up the heat of the morning as that first true awaking of warmth leisured the land.


Survey Result:


Craig Garth Bwlch

Summit Height:  398.6m (converted to OSGM15, and average of two data sets) (390m Sub-Pedwar status confirmed)

Summit Grid Reference:  SJ 01822 18135

Drop:  54m

Dominance:  13.55%


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




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