Friday, 11 October 2019

Mapping Mountains – Trimble Surveys – Pumlumon


23.07.19  Y Gribyn (SN 924 918)

LIDAR image of Y Gribyn (SN 924 918)

With predicted temperatures in the 30s it wasn’t a day to spend hours on the hill multi-hill bagging.  Just one would suffice, ideally relatively low in height, not far to walk, but a walk that had variety and gave good views.  Y Gribyn ticked all these and as it was only a couple of miles from where I met Suzanne in Llanidloes it proved an ideal hill for the day.

Prior to the walk I had LIDARed the summit and connecting bwlch of this hill and with ten figure grid references noted, I met Suzanne in Llanidloes at just past 9.00am.  She arrived with a car full to busting for her impending move in to her new flat, and with a 4.00pm appointment to pick the keys up it meant we were in no rush, so a leisurely vegetarian breakfast in the Great Oak café and a wander in to a charity shop and the Great Oak bookshop could be enjoyed.

By the time we had found a parking place up valley from the small community of Llawr-y-glyn the temperature was roaring upward and blue skies pieced all around and a multitude of hues of green cascaded from the summer growth.  It was a good day to be out!

Our route took us a few metres up the continuation of the paved lane where a public footpath entered Coed y Gribyn on our right.  The path through the wood proved delightful with dappled sunshine swaying shaded patterns on dead leaf foliage which lay on dried earth forming a soft blanket to our slow uphill progress.  It was a day not to be rushed and any stop was welcome.

The initial path through Coed y Gribyn
The path led diagonally up through the wood gaining height at a steady gradient, before it emerged in to the glare of heat where a fence led to a gate which gave access to the field where the connecting bwlch of Y Gribyn is situated.  As I headed toward the point to survey with Trimble in hand directing me via the ten figure grid reference produced from LIDAR analysis, Suzanne stood in the sun with her newly fashioned swishing stick away from where the Trimble was soon to be placed.

On the higher part of the path through Coed y Gribyn

As the Trimble beeped away gathering bwlch data I joined Suzanne and waited whilst the equipment did its stuff.  Once the allotted data were gathered and stored I switched it off, took a few photos and re-joined Suzanne who was heading toward the gate which gave access toward a track that swung around the western side of the upper section of the hill.

Gathering data at the bwlch of Y Gribyn

Leaving the track the summit rears up just beyond a small quarried area, its high point consists of cropped grass and flinted rock and is a part of an attractive small ridge that descends southward.

Suzanne heading toward the summit of Y Gribyn

As the Trimble gathered summit data we sat in the sunshine chatting and enjoying the extensive view down the valley toward Trefeglwys, with Bryn y Fan prominent to our south.  Once allotted data were stored the warm conditions and view dictated another laze in the sunshine.  It proved a struggle to get back up.

Gathering data at the summit of Y Gribyn

Distant views of Bryn y Fan

Contemplation

Leaving the summit we re-joined the gravelled track which soon joined the narrow paved lane leading down toward the old, but now renovated, buildings of Y Gribyn, where I made place-name enquiries and with the hill confirmed as the same as that of the old farm, we continued on a public footpath re-claiming lost height to the corner of a field where Coed y Gribyn plunged steeply down to the narrow lane where the car was parked.

Summer grasses

All that remained was to find the continuation of the footpath as it entered the wood, which we did, and down we happily walked on a narrow path that must seldom be used, but which was beautiful as it tranquilly swept down through open deciduous trees with dappled light swaying to the rhythm of breeze blown sunshine, twas good to be out.



Survey Result:



Y Gribyn

Summit Height:  347.8m (converted to OSGM15)

Summit Grid Reference:  SN 92439 91802

Bwlch Height:  314.0m (converted to OSGM15)

Bwlch Grid Reference:  SN 92376 91952

Drop:  33.7m

Dominance:  9.70%





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