Tuesday 22 October 2024

Mapping Mountains – Trimble Surveys – Glyder Fawr


14.08.24  Pt. 914.9m (SH 659 585) 

My expectations were high as I admired the rocky bulk of Glyder Fawr from the warm cradle of Cwm Bochlwyd.  I had previously been thwarted in an attempt to survey the largest of the pinnacles situated on the north-east ridge of Glyder Fach.  On that occasion, I had come ill-equipped for winter conditions, which precluded a direct ascent of the ridge from Bwlch Tryfan.  Revising the plan, I had then tried to descend to the pinnacle from the summit plateau of the mountain, but owing to the ground conditions, was forced to dampen my ambitions and be content with surveying just the higher of two significant pinnacles found on the ridge.

Glyder Fach from the shore of Llyn Bochlwyd.  Photo: Aled Williams

Arriving at the base of the ridge provided welcome respite from the sun.  After a short break, I started climbing the gully that provides the easiest route to the upper ridge.  The coned-profile of Tryfan basking in evening light dominated the view out from its confines.  The scrambling was entertaining and brought back good memories of various ascents made during the last 20 years.

The view down the gully.  Photo: Aled Williams

The distant sound of walkers heading back to civilisation confirmed my hopes that I would have the ridge to myself.  This would greatly help the task of surveying, which was now imminent.  The view of the pinnacled upper ridge was as impressive as I recalled and I began to wonder what surveying challenges would be presented.

The continuation of the ridge toward Glyder Fach.  Photo: Aled Williams

Thankfully, the summit of the pinnacle was relatively easy to survey.  I used my rucksack to create a platform whereby the receiver of the Trimble GeoXH 6000 was mounted on the highest point of rock.  As I secured it in place, I noted the drop on the eastern side and a sense of dread hit me as I thought of Myrddyn’s expensive surveying equipment plunging down into the upper recess of Cwm Tryfan!

The Trimble GeoXH 6000 gathering data at the summit of Pt. 914.9m (SH 659 585).  Photo: Aled Williams

The Trimble GeoXH 6000 gathering data at the bwlch of Pt. 914.9m (SH 659 585).  Photo: Aled Williams

A short bit of down-climbing brought me to the bwlch.  The low point was found to be a notch close to the base of the pinnacle.  As I anticipated that the Trimble would struggle to reach its accuracy level in such a tight spot, I decided to elevate the equipment on my rucksack and took an offset using a tape measure.  No problems occurred during measurement and after 8 minutes of data gathering I closed the Trimble off.

A fine addition to the ranks of Welsh Highland Subs.  Photo: Aled Williams

The Trimble GeoXH 6000 set-up position at the bwlch.  Photo: Aled Williams

I then sauntered up the remainder of the ridge, passing over the lower prominence, albeit higher in elevation, pinnacle that I had surveyed the previous year.  As I arrived on the summit plateau of Glyder Fach, signs were apparent that the weather was changing.  A bank of cloud was rapidly filling in Nant Gwynant and a chilling breeze was picking up in strength from the south-west.  My visit was well timed.  By the time I returned home, rain and high winds had set in.

Wisps of evening mist gathering around Castell y Gwynt


Aled Williams (August 2024) 

 

Survey Result: 

 

Pt. 914.9m

Summit Height:  914.9m (converted to OSGM15) (significant height revision)

Summit Grid Reference:  SH 65981 58563

Bwlch Height:  904.4m (converted to OSGM15)

Bwlch Grid Reference:  SH 65982 58556

Drop:  10.5m (Welsh Highland Sub addition)

Dominance:  1.15%

 

 

For further details please consult the Trimble Survey Spreadsheet

 

 

 

  

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