Mapping Mountains – Trimble Surveys – Y Berwyn

 

02.04.21  Garth Goch (SH 952 357) and Garth Rhiwaedog (SH 950 349)

The brackened slopes of Garth Goch (SH 952 357)

Having visited and surveyed the hills around and including Y Garnedd (SH 741 431) with Aled earlier in the day and with the weather set fine, albeit with a chilled easterly wind, I wanted a small walk and survey on the way home and combining Garth Goch with Garth Rhiwaedog was ideal. 

I’d previously visited these two hills but had not surveyed them, but each had been LIDARed prior to this walk.  I remember Garth Goch had an impressive boulder on its summit, but otherwise and without reading the notes from my bagging journals, I have little memory of either hill. 

LIDAR image of Garth Goch (SH 952 357)

LIDAR image of Garth Rhiwaedog (SH 950 349)

The conditions on top of Y Garnedd were gloriously sunny but the east wind chilled proceedings; I hoped that as these two hills are significantly lower in height that the continuing wind wouldn’t have such an impact. 

I parked between the two hills, just off of the B4391 road as it makes its way from Y Bala over the Y Berwyn.  A path through bracken led up Garth Goch past yellow gorse bushes that vividly sparkled in the sunlight.  The path led all the way to the impressive boulder at the summit of the hill. 

Whilst on the hills leading to Y Garnedd I carried three small rocks in my pockets to position against the Trimble and keep it wedged in place against the wind whilst gathering data.  After getting to the top of the boulder at the summit of Garth Goch I descended and then assessed the boulder and picked the very highest bit of summit rock to align with the Trimble’s internal antenna.  Once the equipment was aligned with the high point of the boulder I placed the three rocks against the sides of the Trimble, wedging it in place and making it stable. 

Gathering data at the summit of Garth Goch

Once the 0.1m accuracy level was attained before data should be logged, I set it to gather data, scrambled back down the boulder and enjoyed the sunshine, blue skies and view.  Garth Goch is a fine small hill, easily past when driving toward Y Bala, but its shape is attractive, and with brackened slopes, good paths and coloured gorse bushes a visit to its summit makes a good small outing. 

The Trimble set-up position at the summit of Garth Goch

Once the allotted data were gathered and stored I closed the equipment down, packed it away and headed down in a different direction toward another large boulder where a plaque proclaims that the first recorded sheep dog trial took place on this site and the field opposite in October 1873.  I remember walking up the path leading to this rock with my father many years ago; he was of an age that he could only look at it from a distance and not manage the last steepening bit of grassed path that leads directly up to it.  This memory brought me a contented feeling from days that are now long gone. 

The plaque on the boulder

The site of the first recorded sheep dog trial

The greened path from this boulder led down to the B road, from where it was only a short walk to the paved access lane that leads to Ty’n-y-coed farm.  The lane is designated a public footpath as is the continuation through an adjacent field which then gave me access toward the upper part of the second hill of this walk; Garth Rhiwaedog.  This hill shone greened with pasture against the early April sun when I was on Garth Goch.  Its slopes were dotted with sheep and whitened lambs in tow.  These were scattered amongst an attractive copse of mature trees.  Not yet in bud the trees reached skyward skeleton like with their branches forming a myriad of ever diverging patterns. 

Garth Rhiwaedog (SH 950 349)

I slowly gained height toward the summit of Garth Rhiwaedog, overheating on the way.  The lane leading to the field and the trees gave shelter from the easterly breeze and I’d considered converting my walking trousers to shorts, but as height was gained and any semblance of shelter lost, I was again glad that I was wrapped up against the elements. 

Gathering data at the summit of Garth Rhiwaedog

The summit of Garth Rhiwaedog consists of a slight raised grassy knoll with a small circular flattened stony patch where sheep lick was set in a bucket.  The Trimble was soon set up gathering data and whilst it did its stuff I sat on a rock and looked out toward the high Arenig, their pointed summits blued grey in the afternoon light. 

Arenig Fawr from the summit of Garth Rhiwaedog

Once the allotted data were gathered and stored and the equipment closed down and packed away I retraced most of my inward route back to my car, only diverging to use a different gate high on the hill.  During my descent lambs scattered across the field, all except for one, by now I had stopped as I did not want to scare either a mother or a lamb from each other.  During this one of the lambs walked straight up to me and nuzzled my leg, no doubt it was used to human company.  It stayed there for a minute or so before scampering off. 

It had proven another good day on the hill with two walks completed, six hills surveyed, resulting in a lot of data to now process. 

 

Survey Result:

 

Garth Goch

Summit Height:  220.1m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SH 95273 35766 (Trimble GeoXH 6000)  

Bwlch Height:  184.9m (LIDAR)

Bwlch Grid Reference:  SH 95164 35543 (LIDAR)

Drop:  35.2m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  15.99% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

Garth Rhiwaedog

Summit Height:  252.5m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SH 95087 34981 (Trimble GeoXH 6000) 

Bwlch Height:  216.6m (LIDAR)

Bwlch Grid Reference:  SH 94742 34850 (LIDAR)

Drop:  35.85m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  14.20% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet