25.08.18 Mynydd Ystradffernol (SN 937 009)
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| Mynydd Ystradffernol (SN 937 009) |
I’d visited Mynydd
Ystradffernol twice before, the first time just to its 516m trig pillar which
is situated on the southern part of its uppermost 510m ring contour, whilst on
the second visit I floundered in the conifer plantation that encloses the upper
part of this hill reaching a point I judged to be the highest amongst the
trees, but today with the assistance of Mark and Aled I had every intention to reach
the high point of a forest break that many consider the true summit of this
hill.
We parked beside the A
4061 road in a car park full of back-up vehicles associated with the SD
Sealants Junior Tour of Wales 2018, whose second stage had just finished. From here a path leads eastward skirting
mature conifers to an access track for the large wind farm that now dominates
this hill.
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| Heading toward the access track beside the turbines |
The access track
certainly eased progress and it conveniently led down toward the connecting
bwlch of this hill. This was positioned in
a watery bog and my colleagues judged the critical point to be placed just to the
west of the track, I decided that it was safer for the Trimble to be placed on
terra-firma and we proceeded to take a measurement offset using a walking pole and
a small spirit level placed at a 1m height, between the watery lagoon and the
Trimble set-up position, once completed Mark and Aled sauntered off to sit
beside one of the large turbines whilst the Trimble gathered its allotted data.
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| The Trimble set-up position at the bwlch of Mynydd Ystradffernol |
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| Aled and Mark waiting beside one of the turbines for the survey at the bwlch to be completed |
Once data were stored I
packed the Trimble away and we continued heading south-eastward to the end of
the track, we now had two options for our onward route to the summit and decided
on the one directly in front, this consisted of a wide forest break which I had
walked down in the opposite direction on my second visit to this hill, it led
over ground reclaimed from felled forestry up to a fallen tree which barred
direct access, once past this we joined the forest break that would take us
toward two points that vie for the accepted summit of this hill.
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| Heading up the first forest break from the end of the access track toward where a fallen tree bars direct progress |
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| Heading up the second forest break toward the summit which is just around the corner on the right |
The first of these was
in a small clearing and this at least gave hope of a good data set being
gathered by the Trimble, and once the 0.1m accuracy level was attained I
pressed ‘Log’ and sat beside Aled and waited for the allotted data to be
gathered and stored, during which Mark ventured further down the continuation
of the forest break to investigate the second high point that vies for the
recognised summit of this hill.
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| Gathering data at the summit of Mynydd Ystradffernol |
After the Trimble was
closed down Aled and I investigated land close to its set-up position but
within the trees and improvised a levelling method to measure back from this
point to the Trimble set-up position in the clearing, the height difference
came to 3cm, therefore we concluded the ground hereabouts was of equal height.
As we set off toward the
other high point which was immersed in trees Mark was walking back toward us,
and although he thought it next to impossible for the Trimble to gather data
amongst the trees, we proceeded to the point Mark had found and miraculously
the Trimble attained its 0.1m accuracy level relatively quickly and another
seven minute data set was gathered and stored.
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| The Trimble set-up position at the second point surveyed for the summit of Mynydd Ystradffernol |
Once the second Trimble
summit data set was complete the equipment was closed down and Aled and I re-joined
Mark at the small clearing and retraced our route out of the trees, back on to
the track which took us northward toward my car.
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| Heading back to re-join Mark who was waiting in the small clearing |
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| Mark bi-passing the fallen tree on our way back toward the access track |
By now the sun was
casting late afternoon colour across the land, and we thought our optional
fourth walk may have to be postponed for another day, but we still had time to
visit Mynydd Ton.
Survey Result:
Mynydd Ystradffernol
Summit Height: 517.8m (converted to OSGM15)
Summit Grid Reference: SN 93790 00902 (summit relocation confirmed)
Bwlch Height: 484.9m (converted to OSGM15)
Bwlch Grid Reference: SN 92961 02194
Drop: 32.9m (500m Twmpau status confirmed)
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