Mapping Mountains – Trimble Surveys – Moel y Gamelin

 

20.09.21  Bryn y Gaer (SJ 313 574) 

Bryn y Gaer (SJ 313 574)

With the weather set fine and a pocketful of ten figure grid references I decided to head north again, to a similar area to where I visited four days ago.  Then I surveyed three hills close to Rhydtalog, today I hoped to visit and survey four hills close to Yr Hôb (Hope), Sydallt and Brymbo.  Two of these summits were immersed in woodland, therefore I did not know whether Trimble data could be gathered, but the other two were on open land, and waiting in woods for the Trimble to do its stuff is something that I am now accustomed to, and with the whole day to visit four relatively small heighted hills, I was in no rush whatsoever. 

The first of my four hills planned for the day is situated between the B5373 and the A550 roads and is positioned above the village of Yr Hôb (Hope).  The summit area is wooded and the hill was originally listed under the name of Caer Estyn, which as its name implies is that of an ancient hill fort positioned on the slopes of this hill.  However, the listed name of this hill was changed to Bryn y Gaer when updating the Dominant list. 

Prior to visiting this hill I had read online logs that the wood enclosing the summit mainly consists of birch trees, these are wonderful in autumn as they give a succulent bronzed colour.  I had contemplated leaving this walk for another four – five weeks when that autumnal colour is reaching its peak, but decided to take the opportunity today. 

The sun was shining down from a beautiful early morning sky as I drove toward the hill.  I approached Bryn y Gaer from the south having parked close to the public footpath leading up Rock Lane.  Having walked up the lane past a number of houses I entered the wood and followed a footpath on the left.  This gained height and weaved its way above the remains of a large old quarry.  Sunlight glimmered through the overhead canopy; the path was dry and the hill quiet, it was a wonderful place to find myself at this time in the morning. 

Woodland walks have a beauty all to themselves; they have tranquillity different to that of many hills.  Their pathways lead, and their trees march upward, their enclosed nature is at contrast to that of an open hill and perhaps it is this contrast that is part of their appeal. 

The path leading to the summit of Bryn y Gaer

I continued following the path, one or two alternate routes bisected from it, but the path I had chosen was leading ever upward and so it did until taking me to within a few metres of the summit. 

Prior to visiting this hill I had analysed its summit and bwlch via LIDAR, building up contours and noting each height and ten figure grid reference.  Once at the summit area I switched the Trimble on and compared its co-ordinates with those produced from LIDAR. 

LIDAR image of Bryn y Gaer (SJ 313 574)

Following the LIDAR co-ordinates the Trimble took me in to a morass of bracken and bramble close to the path I had walked on.  I circled a route in the undergrowth testing how solid the ground was and how high in comparison to ground where the path was positioned. 

I thought ground in the morass of bracken and bramble to be the high point, but I was not going to try and set the Trimble up in such diabolical terrain and therefore slowly made my way out of the undergrowth back to the path.  I assessed the path from a number of directions and chose a spot for Trimble placement.  If data were gathered this would at least give me a comparison between its position and that ascertained from LIDAR analysis, although due to the enclosed nature of the set-up position I had little hope that any Trimble data would be accurate. 

It was a long process waiting for the 0.1m accuracy level to be attained before data should be logged.  I waited for about 15 minutes and eventually decided to press ‘Log’ and walked back down another path and stood behind a tree whilst data were gathered and stored. 

Gathering data at the summit area of Bryn y Gaer

It proved a lovely place to stand and just listen to the wood, a quiet experience with just a hint of breeze blown movement.  Some sunlight pieced the overhead canopy, but otherwise I stood in shade and enjoyed every minute of my wait. 

Once data were gathered and stored, I closed the equipment down, packed it away, took a few photographs and retraced my inward route back to my awaiting car.  Here I met a dog walker; we chatted and commented on how lovely the morning was, I asked him about the name of the hill, as I had with a woman taking her daughter out when I first arrived, both told me the hill is named Bryn y Gaer. 

 

Survey Result: 

 

Bryn y Gaer (significant name change)

Summit Height:  153.9m (LIDAR)

Summit Grid Reference:  SJ 31381 57459 (LIDAR)

Bwlch Height:  95.8m (LIDAR)

Bwlch Grid Reference:  SJ 31774 58223 (LIDAR)

Drop:  58.1m (LIDAR)

Dominance:  37.74% (LIDAR)

 

 

For further details please consult the Trimble Survey Spreadsheet