17.11.18 Clip (SH 654 329), Craig Ddrwg (SH 656 331), Craig Ddrwg (SH 656 333), Corn Ystwc (SH 655 336), Pt.
594.2m (SH 656 337), Pt. 579.2m (SH 657 342), Moel
Ysgyfarnogod (SH 658 345) and Foel Penolau (SH 661 347 and SH 661 348)
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| Moel Ysgyfarnogod (SH 658 345) and Foel Penolau (SH 661 347 and SH 661 348) |
There are many upland places
in Wales that have special qualities, but the northern Rhinogydd is an area
that cannot be matched. It is a land
where rock strewn crag and moor meet. It
is a complicated land where the profusion of rock up thrusts, many with steep
slopes and sheer cliffs would add unwanted adventure if clag and mist descends
to its summits.
Aled and I ventured in
to this land and planned a traverse of it northern hills from Clip to Foel
Penolau, and with a forecast of November cloudless skies we hoped that this would
give us sufficient daylight hours and suitable weather to visit all the
summits, and with the Uchafion as the benchmark this would mean eight in all.
As we followed the
moorland track toward the abandoned old farmhouse of Wern-fach most of
north-west Wales bathed in clear skies with dark silhouettes of hills following
our car journey south. However, this
part of the country steadfastly clung on to low cloud that grasped the tops and
worrying for us especially so for this part of the Rhinogydd. There are few places in Wales where I have
promised myself not to venture when mist enshrouds the hills, and this is
one. But with the forecast of any low
cloud clearing we hoped that this would take place before we reached the ridge
and the final steep ascent of our first hill of the day; Clip.
Glimmers of clear sky to
our east gave hope that the clag would rise, and as we followed the moorland
path from Wern-fach beside the Afon Crawcwellt patches of sunlight illuminated the
lower hillsides, with intense colours against the moor.
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| Early morning clag as we approach the northern Rhinogydd |
The path proved wet with
many small bog infested brooks to jump or delicately wade over. As height was gained the clag seemed to
descend and as we continued below the great bulk of Craig Ddrwg we were in mist. However, as the clag started to envelop us
large ripped tears above showed blue sky and the increasing strength of the
wind whipped the morning mist upward and past us as it quickly rolled up the adjacent
hillside.
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| The view east with the first glimmer of sunlight |
We were now at the bwlch
between Clip and Craig Wion and watched as the shrouded world around us was
quickly exposed, with Rhinog Fawr to our south dominating the distant view, its
summit clear to the heavens and yet delicate mist banks meandered around its
lower slopes.
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| Rhinog Fawr |
From here a steep path
led to Bwlch Gwilym and the ridge that would now occupy us for the remaining daylight
hours. Our arrival on the ridge was
perfectly timed as the northern part was still being ripped of its morning clag
whilst immediately to our south Clip rose against blue sky.
I slowly followed Aled
to the summit of Clip, stopping on the way to join him as he shouted over
‘brocken spectre’, and there below cast against the whipped mist was a coloured
halo, appearing and then quickly disappearing as the mist was pushed away from
the mountains. Reaching the summit we
were met by strengthening wind which complicated surveying and also at times
communication. Thankfully this lessened
as we progressed on the ridge and only increased again as we reached the higher
summits further north.
The summit of Clip is
easily identified and as with many of these high points, consists of rock. The Trimble was soon perched on its high
point and gathering data; the first of eighteen data sets taken during the next
five hours.
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| Gathering data at the summit of Clip |
Once data were stored I
packed the Trimble away and we headed down to its connecting bwlch which proved
easy to identify. Once there, I quickly
assembled the Trimble on top of my rucksack, with this acting as an improvised
tripod, and measured the offset between its internal antenna and the ground at
its base and waited until the allotted data were gathered and stored.
We knew that at least 15
data sets would be taken during the day, some of which were prioritised as
their respective summits were marginal, others were not directly associated
with the status of the hill and realising that daylight hours were against us many
of these non-priority surveys would be reduced in time from the usual five
minute data set to the minimum two minutes that Trimble recommend.
Our next hill of the
day; Craig Ddrwg consists of two summits, both of which we planned on surveying, with the southern being one metre higher
on the map, and as we approached its profile thrust upward in a pile of rock,
it was a stunning view, and now accentuated as I imagined we would be in thick clag
on this part of the ridge, and as it was now clear my mind relaxed and was enhanced
with the feeling of wild openness these hills give.
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| Craig Ddrwg (SH 656 331) |
The high point of Craig
Ddrwg is placed about eight metres from a cairn and the Trimble was soon wedged
in place aligned to its highest point and beeped away gathering its allotted
data.
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| Gathering data at the summit of Craig Ddrwg |
The mist had now
completely cleared from these hills and the view north was stunning, with rock
carved hill and mountain lake dappled in the morning sunshine screaming out to
be investigated.
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| The wild beauty of Craig Ddrwg |
Our next planned bwlch
survey consisted of two potential critical points, and reaching these,
assessing the lay of land in their heathered depths and then taking the two
data sets would probably add thirty minutes to the days surveying, and as this
would impact upon surveying Foel Penolau we decided that this bwlch could be
left for another day. This proved the
only bwlch that we did not survey on this part of the ridge and as the
afternoon progressed and daylight hours slowly ebbed away it proved a wise decision.
The next hill was
another carved in rock with its summit easily identified and very soon
Trimbled. The surveys were now coming
thick and fast with barely a moment to relax between each one.
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| Gathering data at the summit of Pt. 594.2m (SH 656 337) |
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| Yr Wyddfa |
Its connecting bwlch was
in shade and placed in wet land just to the east of Llyn Du, it was soon
Trimbled and once data were gathered and stored and the equipment packed away
we headed up to the summit of our next hill.
During Aled’s place-name research he gathered names for all these hills,
but these names will wait until the Yr Uchafion list is published, so for now
their names will be documented under the point notation.
Flat bedded rock with
gauged out fissures led pavement like toward the bulbous summit of our next
hill which is given a 578m map height.
It was a sheer joy to be on this ridge in these conditions with the
mornings clad a thing of memory and low angled sunlight flowing over the
hills. Away to our north the higher
Eryri peaks floated skyward, whilst the high Aran and Arenig were now sun
bathed, their ridges edged against the sky.
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| The fissured slabs of our next hill to survey |
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| Gathering data at the summit of Pt. 579.2m (SH 657 342) |
Only one survey remained
before we tackled the two higher peaks of Moel Ysgyfarnogod and Foel Penolau
and this was the next connecting bwlch which is the critical bwlch for the
higher of the two Craig Ddrwg summits, and it was positioned in a large expanse
of wet land. Once data were stored we
headed upward on grassed hillsides which are at odds with the rest of these
hills, leading to the trig pillar atop the highest hill of the day; Moel
Ysgyfarnogod. By the time I reached its
summit I felt knackered.
The untidy cairn beside
the trig pillar swarmed outward toward a small rock outcrop which is the high
point of the hill. As the Trimble
gathered data I sat with Aled beside the trig eating a banana, the first food
I’d had all day.
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| Gathering data at the summit of Moel Ysgyfarnogod (SH 658 345) |
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| Foel Penolau from Mowl Ysgyfarnogod |
All that remained was
the survey of Foel Penolau, this hill has a complicated bwlch consisting of a
boulder field and two tops given the same 614m map height. To do this hill surveying justice would take
time, and thankfully we had sufficient daylight hours remaining to complete the
survey.
On our way toward the
hill Aled suggested that I should take a data set from where the 588m spot
height appears on the Ordnance Survey Interactive Coverage Map hosted on the
Geograph website, this is taken as the height and position of the connecting
bwlch for Foel Penolau by some, giving it 26m of drop, but the 5m contouring on
OSMaps indicates the critical bwlch is placed in the boulder field at the base
of the hill’s vertical southern cliff, and interpolation of these contours
gives this hill nearer 30m of drop.
I quickly set the
Trimble up at the first bwlch position and once data were stored, packed it away
and we headed to the boulder field. It
is this boulder field that John Kirk first hypothesised on whether a col should
be viewed from the prospective of an ant or a human; as the south facing cliff
of Foel Pelolau has deposited large boulders at its base over many years and if
a person used these to connect on the hill to hill traverse the hill would have
less drop compared to taking the ground below the boulders as that for the
bwlch. We had already debated this by
the time we arrived and the two of us agreed that if there were gaps below and
between the boulders we would treat this bwlch like an ant and take the height
of the bwlch to land at the base of the boulders.
The boulder field is
placed directly below the vertical southern face of Foel Pelolau, this is an
impressive place and one that I had not visited for many years. We started to examine the base of the
boulders that stood steadfast in the positions that they had fallen, huge lumps
of rock with gaps between and daylight peering under many of them.
This bwlch is not an
easy place to judge where its critical point lies, but Aled soon followed the
course of land between the boulders from where the grassed hillside to the
south enters the boulder field on the hill to hill traverse and there were gaps
under many of the larger boulders indicating to us that it is the ants viewpoint
that should be followed in determining where the critical bwlch of this hill
lies.
Having judged our best
position for this hill’s critical bwlch I placed the Trimble on top of the
boulder above it and Aled climbed down in to the gap at its side and we
measured the offset between the ground at its base and the Trimble’s internal
antenna, and then waited for five minutes of data to be gathered and stored.
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| Measuring the offset |
During data collection
Aled headed up the near vertical cliff and found a route through to its easier upper
part, and then peered back down at me as I sat behind the boulder with the
Trimble beeping away gathering its allotted 300 datum points.
Once the Trimble was
packed away I slowly plodded up the steep boulder field as it cascaded down
from the upper part of Foel Penolau, and joined Aled on the southern summit of
the hill. The Trimble was soon aligned
with its high point and data being gathered.
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| Gathering data at the southern summit of Foel Penolau (SH 661 347) |
Dropping steeply off its
summit to the bwlch between it and this hill’s northern summit we now surveyed
the bwlch between its two tops and sat in a natural wind shield with a rock
carved seat and roof as the Trimble gathered its penultimate data set of the
day. All that remained was the last of
eighteen data sets to be taken from the summit of the northerly top.
We were soon at its high
point and as the Trimbe gathered data Aled investigated the northern route off
the hill and came back reporting that he had found a path. Closing the Trimble down and packing it away
I stood for a moment and looked south at the profiles of these hills silhouetted
against a lowering sun. I didn’t want to
leave, but knew I would.
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| Gathering data at the northern summit of Foel Penolau (SH 661 348) |
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| Aled admiring the view toward Yr Wyddfa |
The route down was good,
although boggy in places and we soon connected with the track that leads down
toward the farm of Cefn Clawdd, from here it was only a short walk to where
Aled’s car awaited. It had been a good nine
hour day on the hill, with eighteen data sets taken and a number of marginal
hills surveyed.
As Aled drove back to
Porthmadog I sat in his car and relaxed.
I was tired and my legs ached, but these were periphery to the inner
glow that such a day on the hill had given me.
Postscript:
As the connecting bwlch
of Foel Penolau consists of a boulder field that complicates the position of
its critical point I wanted to re-visit and take further data sets on the
valley to valley traverse. By doing so I
hoped that all eventualities would be covered.
Therefore, nine days
after visiting the hill with Aled I headed to the northern Rhinogydd again,
never a bad thing to find oneself doing!
The weather forecast was good with little breeze and low cloud breaking
up and sunshine predicted for the afternoon.
I walked in from the
west following an old quarry track leaving the minor dead end road close to the
last farm of Cefn Clawdd. As I travelled
west toward these hills I’d passed through rain and low hill cloud, and
although their tops were clear when I set off banks of murk slowly rolled westward
and I knew I would probably be in mist whilst doing at least part of the survey.
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| The approach toward Foel Penolau on the second survey |
The surveys concentrated
on the boulder field and I wanted to build up a series of surveyed points on
the valley to valley traverse heading from west to east. This would give a good rendition of the lay
of land and importantly its height. I’d
also brought my digi-camcorder as this would be able to document the land of
the boulder field much better than any photograph.
Height was soon gained
and once the track gave up its forlorn route I headed up toward a small weather
beaten gate giving access to the open, upper part of Moel Ysgyfarnogod.
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| Looking out toward Rhinog Fawr |
Wanting to visit the
summit of the two 2,000fts I followed the narrow path up toward the small rock
outcrop a few metres from the trig pillar at the summit of this hill. All around was November murk, with odd
glimmers of light breaking through the upper cloud base. It was remarkably still and quiet, seemingly without
anyone for miles around.
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| Early morning mist gathering around Yr Wyddfa |
I filmed a quick
introductory video from beside the summit and then headed down to where the
Ordnance Survey Interactive Coverage Map hosted on the Geograph website places the
588m spot height which has been taken as the height of the critical bwlch for
Foel Penolau by some. When visiting this
point with Aled he wisely suggested I take a data set from this position, this
proved to be 50 metres from the position of the spot height, and therefore I
now wanted a second data set from this area.
However, this land is higher on the hill to hill traverse compared to
the land of the boulder field. Once the
survey was completed I headed toward the boulder field where I then spent the
next two hours.
I’d left three small
rocks in situ on the boulder where the previous bwlch data set had been taken,
and these were still in place and easy to find, I placed two flags at this
point as I wanted to take a series of data sets leading over the boulder field
and then take a video showing each Trimble set-up position and the land between
and under the boulders.
The next data set I
wanted to take was where the hill to hill traverse enters the boulder field,
and even through there is lower ground on this traverse amongst the boulders it
would give a height to the last bit of grass as it disappears and is swamped by
the rocks.
As I descended toward
the boulder field I visually placed where the land on either side of the
opposing valleys definitely went downhill, and placed a flag at the eastern
point and began the first valley to valley survey at the western point.
This first survey from
the innards of the boulder field consisted of wedging my rucksack in to the
boulders and placing the Trimble on top of it, the measurement offset to the
gap at the base of the boulder was 1.88m.
The whole area was a
mass of jumbled boulders and I wanted to take at least four further data sets
slowly working eastward. The second of
these surveys had the Trimble firmly wedged in place on a pointed boulder. By now banks of mist were rolling across the
hill adding an atmospheric surreal element to proceedings.
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| One of many Trimble set-up positions in the boulder field |
The third position heading
east through the valley to valley traverse was where Aled and I had taken the
bwlch data set from nine days ago, I placed flags at this point and continued
through the boulders.
At this point I took a
break and filmed a video showing the flags and boulder field including some of
the deep gaps between the rocks. Having
packed the digi-camcorder away the fourth Trimble set-up position was on a
boulder with a 1.68m measurement offset taken to the ground below. Each of these offsets were being taken to the
ground at the base of the gap below these boulders, in affect I had become an
ant for the day and was taking a series of measurements based on how an ant
would traverse this land.
The fifth position again
had my rucksack wedged in place between boulders and the Trimble placed on top
of it. The measurement offset was 1.91m
and a five minute data set was taken.
During all these data sets the banks of mist would slowly descend and
then thin. I was now nearing the end of
the boulder field and just had one more data set to take.
The last data set had
the Trimble placed on the top of another pointed boulder with a 1.81m
measurement offset. All except for one
of these data sets were marked with flags, and before leaving the bwlch I
wanted to take another video showing their placement and the lay of land. Gathering all the flags I then headed up on
the jumbled cascade of boulders toward the first of the two Foel Penolau tops.
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| The last Trimble data set taken in the boulder field |
Arriving on the southern
top glimmers of brightness was now breaking through toward the east. I’d brought the lightweight tripod and
antenna to take a series of summit photos with the Trimble in position and set
this up on the high point of the southern top.
Descending to the gap
between the two tops I then headed up to the most northerly summit. When I arrived the murk had been pushed away
and a beautiful late November sky with lowering sun and glimmers of light
heralded a fantastic end to the day’s proceedings.
Before leaving the
summit I again assembled the Trimble attached to its external antenna which was
placed on its tripod. I seldom have need
to use the Trimble connected to its external antenna, but always enjoy seeing
it assembled this way.
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| At the northern summit of Foel Penolau (SH 661 348) |
All that remained was to
descend the cascade of boulders and head toward the small gate and down to the
wet track and back toward by car. It had
taken just under six hours for the walk and a further seven data sets had been
taken to add to the two bwlch data sets and two summit data sets taken whilst
with Aled, and all these surveys will give a good rendition of the drop value
of Foel Penolau.
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| Foel Penolau |
Postscript:
Since surveying these hills full LIDAR coverage is now
available. The LIDAR (Light Detection & Ranging) technique
produced highly accurate height and positional data that is now freely
available for England and Wales. Consequently the numerical details
for these hills have been analysed using this technique, and where appropriate
LIDAR has been used in preference to that produced by the Trimble.
Survey Result:
Clip
Summit Height: 595.3m (converted to OSGM15) (confirmed as lower
than Craig Ddrwg positioned at SH 65659 33162)
Summit Grid Reference: SH 65460 32942
Bwlch Height: 564.0m (converted to OSGM15)
Bwlch Grid Reference: SH 65551 32999
Dominance: 5.26%
Craig Ddrwg
Summit Height: 597.3m (converted to OSGM15) (confirmed as
higher than Clip positioned at SH 65460 32942 and higher than Craig Ddrwg positioned at SH 65681 33373)
Summit Grid Reference: SH 65659 33162
Bwlch Height: 544.2m (converted to OSGM15)
Bwlch Grid Reference: SH 65765 33950
Drop: 53.0m
Dominance: 8.88%
Craig Ddrwg
Summit Height: 596.2m (converted to OSGM15) (confirmed as lower than Craig Ddrwg positioned at SH 65659 33162)
Summit Grid Reference: SH 65681 33373
Bwlch Height: 580.6m (converted to OSGM15)
Bwlch Grid Reference: SH 65675 33179
Drop: 15.6m (Sub-Uchaf reclassified to Uchaf)
Dominance: 2.62%
Corn Ystwc
Summit Height: 587.6m (converted to OSGM15, Trimble GeoXH 6000)
Summit Grid Reference: SH 65569 33640 (Trimble GeoXH 6000)
Bwlch Height: 572.3m (LIDAR)
Bwlch Grid Reference: SH 65595 33642 (LIDAR)
Drop: 15.3m (Trimble GeoXH 6000 summit and LIDAR bwlch)
Dominance: 2.60% (Trimble GeoXH 6000 summit and LIDAR bwlch)
Pt. 594.2m
Summit Height: 594.2m (converted to OSGM15, Trimble GeoXH 6000)
Summit Grid Reference: SH 65671 33789 (Trimble GeoXH 6000)
Bwlch Height: 566.6m (LIDAR)
Bwlch Grid Reference: SH 65783 33558 (LIDAR)
Drop: 27.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)
Dominance: 4.64% (Trimble GeoXH 6000 summit and LIDAR bwlch)
Pt. 579.2m
Summit Height: 579.2m (converted to OSGM15, Trimble GeoXH 6000)
Summit Grid Reference: SH 65744 34211 (Trimble GeoXH 6000)
Bwlch Height: 557.7m (LIDAR)
Bwlch Grid Reference: SH 65579 34435 (LIDAR)
Drop: 21.5m (Trimble GeoXH 6000 summit and LIDAR bwlch)
Dominance: 3.70% (Trimble GeoXH 6000 summit and LIDAR bwlch)
Moel Ysgyfarnogod
Summit Height: 624.0m (converted to OSGM15, Trimble GeoXH 6000)
Summit Grid Reference: SH 65843 34588 (Trimble GeoXH 6000)
Bwlch Height: 441.2m (LIDAR)
Bwlch Grid Reference: SH 65879 29986 (LIDAR)
Drop: 182.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)
Dominance: 29.29% (Trimble GeoXH 6000 summit and LIDAR bwlch)
Foel Penolau
Summit Height: 614.4m (converted to OSGM15) (twin summit
status confirmed with 614.379m and 614.380m respectively, with 1mm difference
the Trimble is unable to split these tops)
Summit Grid Reference: SH 66145 34774 and SH 66184 34832
Bwlch Height: 582.5m (converted to OSGM15)
Bwlch Grid Reference: SH 66099 34735
Relative Bwlch Height to each
summit: 604.5m (converted to OSGM15)
Relative Bwlch Grid Reference
to each summit: SH 66154 34788
Dominance: 5.19%
