Sunday, 13 March 2016

Mapping Mountains – Trimble Surveys – Moel y Gamelin


23.02.16  Pentre Clawdd Gorse (SJ 311 442)  

Pentre Clawdd Gorse (SJ 311 442) is the wooded summit on the left of this photograph

The summit of Pentre Clawdd Gorse is linked with that of Wynnstay Park (SJ 309 429) which is an approximate kilometre due south, and the latter was Trimbled on the 20th October 2015.  During that survey I thought that Wynnstay Park was the summit connected to the bwlch at SJ 307 437, it was only later when examining a number of maps that I noticed that Pentre Clawdd Gorse had two small 140m ring contours at its summit, and as Wynnstay Park was Trimbled as being 141.2m (converted to OSGM15) high and its drop to the bwlch at SJ 307 437 being surveyed as 29.5m, it meant that Pentre Clawdd Gorse could be the higher summit, and if it was surveyed as being 0.5m higher than Wynnstay Park it would also become Wales’ newest P30.

Wynnstay Park (SJ 309 429) from close to the summit of Pentre Clawdd Gorse

Parking next to the Broth Lodge I walked back across the A 539 toward a foot stile giving access to a footpath and field on the north side of the road.  I’d used this same footpath when surveying the bwlch in October of last year, then I’d followed the field ridge fence and connected with another footpath which brought me down to the area of the bwlch, today I remained in the field and followed its ridge northward beside the remains of a section of Wat’s Dyke.

The view over the hedge on the roadside with Wat's Dyke following the left hand ridge from the wooded summit of Pentre Clawdd Gorse

Wat’s Dyke is an earthwork approximately 64 km (40 miles) in length and which straggles the countryside between Maesbury in Shropshire in the south and Basingwerk Abbey near to the River Dee estuary in the north.  For much of this distance it runs parallel with its more famous cousin; Offa’s Dyke.

I hoped that the high point of the first of the two 140m ring contours was not obstructed by undergrowth and trees, as this may prove problematic for satellite reception.  As I gained height I left the field and walked on the Dyke, still following the footpath as it continued through the tree lined canopy.  The first high point proved relatively easy to identify and although it was positioned under a number of trees it had a fairly good view of the sky.  I set the Trimble up on my rucksack and waited in the field below, from this vantage point the Dyke rose by at least 2m from its base and as the 140m ring contour took in the base of the earthwork I thought its height would be sufficient for the hill to gain P30 status.

The Trimble is placed on top of my rucksack and on the high point of Pentre Clawdd Gorse which is a part of the ancient earthwork of Wat's Dyke and which is at least 3m higher than the field at its base

After ten minutes or so the accuracy level attained 0.1m and I pressed Log, and scampered down the bank to wait in the field below.  To my west the continuous hum of traffic on the A 483 steadily meandered its way through the otherwise tranquil countryside.  After pressing the ‘Done’ button on the Trimble I took a number of photographs of it perched on my rucksack at the high point of this section of Wat’s Dyke.

Gathering data from the summit of Pentre Clawdd Gorse

My next and last objective of the day was the second 140m ring contour; this is placed at the top of a turnip field which conveniently has a footpath crossing it close to its summit.  As the Trimble gathered its data I stood admiring the colour cast down on the surrounding land as the afternoon light lit all around.  Just before closing the Trimble down I noticed another high point buried behind a holly tree, this seemed unusually shaped, but when I walked to it, it was solid underfoot, this meant one last Trimble survey was necessary for me to walk away happy in the knowledge that all summit contenders had been surveyed.

Gathering data in a field full of turnips and which constitutes where the second 140m ring contour is placed, with the summit of Pentre Clawdd Gorse in the background on the left of this photograph

This last survey took an age as the Trimbe was obstructed by a canopy of mature trees, I waited patiently for about 15 – 20 minutes until the 0.1m accuracy level appeared before data should be logged, once this magical mark appeared on the screen, I quickly pressed Log and stood behind the trees and waited for five minutes of data to be collected.

The last data set of the day proved to be where an old quarry is marked on old maps

Balanced on top of a solid mound of earth the Trimble gathers its last data set of the day

Looking toward where the second 140m ring contour appears on the ground with the remains of the old quarry hidden in the trees

On my way back I chatted with a man who was out walking his two dogs, I’d noticed him from afar and on my way down the field he had stood motionless, just looking east, taking in the view and the light, when I approached we said our hello’s and both commented what a beautiful afternoon it was.  And indeed it was, a glow was cascading down upon the landscape, a rather magical late afternoon winter’s glow that percolated one’s need to be out in such surroundings and brought a contented happiness to one’s being.     


Survey Result:


Pentre Clawdd Gorse

Summit Height:  142.0m (converted to OSGM15)

Summit Grid Reference:  SH 31131 44252 (summit relocation confirmed)

Drop:  30.3m (converted to OSGM15) (new 100m Twmpau confirmed)

Dominance:  21.34%



Postscript:  It had been a good day on the hill, with four places visited and an impressive reclassification hit rate achieved as evidenced below:

Parc y Borth (SH 558 375) – reclassified from a Dominant to a Lesser Welsh Dominant.

Moel y Gadair (SH 521 391) – reclassified from a 30m – 99m Twmpau to a Sub-Twmpau, and also deleted from the Lesser Welsh Dominants.

Pt. 258m (SH 811 542) – Re-instated as a 200m Twmpau from a Sub-Twmpau.

Pentre Clawdd Gorse (SJ 311 442) – new 100m Twmpau.



For the post detailing the bwlch survey of Pentre Clawdd Gorse please click {here}

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



No comments: