10.05.17
Curnau Mawr (SN 751 750), Craig Lan Las (SN 758 747), Pt. 413.9m (SN 767
751) and Lan Lwyd (SN 761 752)
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| Craig Lan Las (SN 758 747) |
I wanted to take
advantage of the settled weather in the west of the country before predicted
low pressure systems brought their more unsettled conditions toward the end of
the week, and decided to visit four hills to the south-east of Pontarfynach
(Devil’s Bridge). I’d contemplated
visiting these hills for a number of years but had never done so, when studying
maps and potential ascent routes I’d always thought that an ascent from the
Arch on the former Hafod estate would be the best, but as Aled’s continuing
analysis of LIDAR data had found a new 390m Double Sub-Pedwar in Curnau Mawr
(SH 751 750) an ascent of this hill and its adjacent 400m Sub-Pedwar of Craig
Lan Las would make a good circuit from the west when joined with the two Pedwar
hills to the north-east with the Nant Brignant being central on this small
horseshoe.
There aren’t many
options to park a car for convenient access to the public footpath that leads
toward Curnau Mawr, but thankfully a pull-in spot next to a letterbox was
ideal. As I walked up the earthen track
the sky radiated blue and with just a breath of breeze the prospect for the day
ahead and the surveys I planned on conducting was excellent.
I left the track and
walked up the closely cropped grassed south-western slopes of Curnau Bach to
the trig pillar positioned close to the fence boundary where a conifer
plantation swamps the northern side of this and its adjacent hill; Curnau Mawr.
Ordnance Survey maps
give Curnau Mawr a small 390m uppermost contour ring straddling the forest
boundary fence, whilst LIDAR data gives the high point as 391.4m and
approximately 23 metres to the south of the edge of this contour ring in
amongst land between 380m – 390m. When I
approached it was obvious that the LIDAR position for the summit of this hill
was correct.
Having set the Trimble up
on top my rucksack I stood back whilst it gathered its customary five minutes
of data and looked toward my next hill; Craig Lan Las, the underfoot conditions
were wilder on this hill with bleached tussocks portraying what is common on
the Elenydd hills.
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| Gathering data at the summit of Curnau Mawr |
Surveys would come one
after another on this walk with four summits and three or four bylchau to
visit, and the first of these bylchau lay just to the east and firmly implanted
in a bog. All of the points I planned on
surveying had been analysed with LIDAR data by Aled and I had come prepared
with each ten figure grid reference, but I also wanted to independently assess
each survey position and compare these to where LIDAR data indicated each
should be, and on the critical bwlch for Curnau Mawr my estimated bwlch
position was within a few metres of where LIDAR indicated the true bwlch was, I
trusted LIDAR and placed the Trimble at the point that Aled had noted.
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| Gathering data at the critical bwlch of Curnau Mawr |
After packing the
Trimble away I slowly made my way up the steepening western slopes of Craig Lan
Las to two tops, each high point consists of thick grass with the bleached and
dry land of tussock grass all too evident all around. I took data sets from each top, both
attractive slender affairs in a land of flatly rounded summits.
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| Gathering data at the first and slightly lower of the two tops of Craig Lan Las |
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| Gathering data at the second and slightly higher of the two tops of Craig Lan Las |
Beyond the summit of
Craig Lan Las lay its connecting bwlch with Lan Lwyd, this proved a delight and
consisted of heather, tussocks and an odd rouge conifer gaining growth in a big
bog. Approaching the bwlch I had a good
view of how the land slightly rose toward where the valley to valley traverse
met and headed that way, some of the underfoot conditions proved unusual as my
leg occasionally disappeared down beyond where I thought the ground lay, this place
must be seldom visited as any prospective hill bagger would no doubt circumvent
the delights of this bog. I used the
Trimble as a hand-help GPS and let it guide me toward the spot where LIDAR data
placed the critical bwlch, once there I set the Trimble up on top of my
rucksack and proceeded to sit on a clump of relatively dry heather as it
gathered five minutes of data. My view
from the heather was one where the Trimble was only just visible as the heather
and bog had almost swallowed the whole of my rucksack.
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| Lan Lwyd with the connecting bwlch (bog, a big bog, a bigger than a big bog) between it and Craig Lan Las looking decidedly unwelcoming |
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| The view of the Trimble from my heathery perch |
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| Gathering data at the critical bwlch of Craig Lan Las |
During this first part
of the walk I had contemplated my way down, should I backtrack the way I had
come or leave the adjacent summit of Lan Lwyd until the last and follow its
western ridge to connect with a track leading toward the conifer plantation
beside the Nant Brignant, I decided on the latter as I didn’t want to visit the
tussock laden bog again.
Once out of the bog I
followed a green vehicle track toward the bwlch connecting Lan Lwyd with
another Pedwar to its east, it was blissful to be on good walking ground again,
but it had also been good to experience a small part of wildness that these
hills now only have in small patches as much of their land has been reclaimed
for grazing.
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| Pt. 413.9m from the green vehicle track that approaches its bwlch |
The green track turned
in to a graveled track at the bwlch and after the Trimble had gathered another
five minute data set, this time perched on top of a thick gate post with a
1.36m measurement offset between its internal antenna and the ground below, I
continued following the course of the track toward the summit of the next hill
which is given the point notation as it is unnamed on Ordnance Survey maps and
local and historical research has not yet unearthed an appropriate name for it.
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| Gathering data at the critical bwlch of Pt. 413.9m |
I proceeded to take two
data sets, one from the hill’s southern top which is placed in a closely
cropped grazing field and one from its higher northern top which is placed in a
felled forest consisting of scrub undergrowth intermingled with the remains of
felled trees. As the Trimble gathered
data I looked below me and the Arch beside the B 4574 road was only a few
minutes’ walk away, this is where the critical bwlch for Lan Lwyd (the highest
and last of the four hills I planned on visiting during the day) lay, and as
the track descending to the conifer plantation next to the Nant Brignant
originates next to the Arch I could follow it after collecting data beside the
road.
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| Gathering data at the summit of Pt. 413.9m |
With this revised
descent route now firmly established I packed the Trimble away and retraced my
route back on the track toward the summit of Lan Lwyd, the high point was
beside a section of land set aside with daffodil bulbs, as indeed were swathes
of the hill’s south-eastern slopes. Once
the customary data set was gathered I regained the track and followed it down
to the B road and the arch.
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| Craig Lan Las from nearing the summit of Lan Lwyd |
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| Gathering data at the summit of Lan Lwyd |
The Arch was constructed
in 1810 by Thomas Johnes of Hafod to commemorate the Golden Jubilee of George
III. The road used to pass under the
Arch, but after a lorry damaged hit and damaged it the road has now been
diverted, creating what LIDAR data gives as a new position for the critical
bwlch of Lan Lwyd.
Beside the Arch is a
large car park and a number of trails heading off in to adjacent woodland, it’s
usually a sleepy place, especially so on a blue skied day when the pace of life
seems to slow even in a place where the pace of life is probably forever quiet
and slumbered.
Initially I judged the
low point on the hill to hill traverse to be on the southern side of the old
road a couple of metres to the east of the span of the Arch, the Trimble took
ten minutes or so to attain its 0.1m accuracy level before data should be
logged, during this time I chatted with a couple who had just completed one of
the marked trails through the woodland, after they headed toward their car I
spent quite some time looking at the lay of land between the old and new road
and the earthen embankment between, most of the time I judged the old road to
be lower, but the LIDAR grid reference gave the southern part of the new road
as that for the critical bwlch. It was
only after I used my camera viewing window as a level that the new road looked
slightly lower than the old road, I then placed the Trimble beside the new road
and hoped that any passing car would avoid a Trimble fatality.
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| Gathering data at the first and slightly higher of the two bylchau of Lan Lwyd |
Considering where the
Trimble was placed it achieved its 0.1m accuracy level relatively quickly and
as it beeped away gathering its 300m allotted datum points only one car passed
which was fortunate both for satellite coverage and for the safety of the
equipment.
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| Gathering data at the second and slightly lower and critical bwlch position of Lan Lwyd |
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| Looking back at the Arch and the bwlch of Lan Lwyd |
This was the eleventh
and last survey of the day and I packed the Trimble away happy in the knowledge
that these hills had now been analysed with LIDAR data and surveyed with the
Trimble with a mass of resulting data to salivate over!
The track proved a
delight to follow as it made its way over the broad and undulating western
ridge of Lan Lwyd, and down toward the old farm house of Brignant-uchaf, this
is now left to the elements but is still relatively intact although a part of
its roof has recently given in to age and struggle. Today the old house nestled in its stream
valley a forgotten edifice where once people would have worked and played. I looked through an open window inside to
debris, a fire place sat forgotten amongst the remains of an iron bed frame
with a wall and the ceiling gaping open. It was bathed in welcoming sunlight today,
similar to a multitude of other lonely Welsh farm houses dotted across the
land, some still active, others laid bare and slowly rotting, today the remains
of Brignant-uchaf is a relic to times now gone.
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| Craig Lan Las from the track leading to the old farm house of Brignant-uchaf |
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| Brignant-uchaf is now abandoned to the elements |
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| Inside the living room of Brignant-uchaf |
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| Brignant-uchaf |
The track left the old
farm house and I followed it through a gate and in to the conifer forest where
it ended in a large gravelled area, the continuation of the path through the
woodland was narrow and welcome and bathed in afternoon warmth and eventually
brought me out on to open lower hillsides, where another track emerged taking
me down to the B 4343 and a short walk on its tarmacked surface back to my
awaiting car.
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| The path through the forest |
Survey Result:
Curnau Mawr
Summit Height: 391.4m (converted to OSGM15, Trimble GeoXH 6000)
Summit Grid Reference: SN 75154 75006 (Trimble GeoXH 6000)
Bwlch Height: 369.8m (converted to OSGM15, Trimble GeoXH 6000) and 369.8m (LIDAR)
Bwlch Grid Reference: SN 75342 74906 (Trimble GeoXH 6000) and SN 75330 74919 (LIDAR)
Drop: 21.6m (Trimble GeoXH 6000 summit and Trimble GeoXH 6000 and LIDAR bwlch) (390m Double Sub-Pedwar addition) (Sub-Trichant addition)
Dominance: 5.52%
Craig Lan Las
Summit Height: 439.8m (converted to OSGM15)
Summit Grid Reference: SN 75828 74735
Bwlch Height: 414.7m (converted to OSGM15)
Bwlch Grid Reference: SN 76025 74951
Drop: 25.2m
Dominance: 5.73%
Pt. 413.9m
Summit Height: 413.9m (converted to OSGM15)
Summit Grid Reference: SN 76757 75119
Bwlch Height: 381.7m (converted to OSGM15)
Bwlch Grid Reference: SN 76691 75174
Drop: 32.2m
Dominance: 7.78%
Lan Lwyd
Summit Height: 445.4m (converted to OSGM15)
Summit Grid Reference: SN 76171 75270
Bwlch Height: 378.0m (converted to OSGM15)
Bwlch Grid Reference: SN 76517 75545
Drop: 67.4m
Dominance: 15.13%
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