Mynydd Graig Goch (SH 497 485) – SubHewitt reclassified to
Hewitt
This is one in a series of retrospective Hill
Reclassification posts that detail hills whose status has altered in the
listing of the Welsh Hewitts (an acronym for Hill in England, Wales or Ireland over Two Thousand feet high). These reclassification posts will give details
of hills where I have had direct association with their change of status, and
they will tie in with a forthcoming Change Register giving detail to this list
and its alterations since first publication.
The listing of Welsh Hewitts was published in booklet format by TACit Tables in February 1997 and
entitled The Hewitts and Marilyns of
Wales. This list evolved out of The
Absolute Summits of England and Wales which were known as the Sweats (an
acronym for Summits in Wales and England Above Two-thousand FEET) and which was published
by Cicerone Press in 1992 in the book entitled The Relative Hills of Britain.
The list compiler for the Hewitts and the preceding Sweats is Alan
Dawson.
When the Welsh Hewitts list was published in booklet format
there were 137 qualifying hills listed with their criteria being any Welsh hill
at or above 2000ft (609.6m) in height with 30m minimum drop, accompanying the
main list are two sub category’s entitled SubHewitts,
with the two sets of criteria being any Welsh hill at or above 600m and below
2000ft (609.6m) in height that have a minimum drop of 30m and any Welsh hill at
or above 2000ft (609.6m) in height with 20m or more and below 30m of drop.
 |
| The Hewitts and Marilyns of Wales by Alan Dawson |
The details for the hill reclassification appear below:
The name of the hill is Mynydd Graig Goch, and it is adjoined
to the western end of Crib Nantlle (Natlle Ridge) which forms a part of the
Moel Hebog group of hills, and it is positioned with the A487 road to its west
and the A4085 road and the village of Beddgelert towards its east, and has the
towns of Porthmadog towards its south-east and Caernarfon towards its north.
 |
| Mynydd Graig Goch (SH 497 485) |
Prior to this hill’s reclassification to Hewitt status it was
listed as a SubHewitt with an estimated c 71m of drop based on the 609m summit
spot height that appeared on the Ordnance Survey 1:50,000 Landranger and
1:25,000 Explorer maps of the day and an estimated bwlch height of c 538m.
As its 609m summit spot height was near the benchmark height
of 2000ft (609.6m) it was prioritised for a GNSS survey by John Barnard who
approached Leica Geosystems suggesting that a joint survey with the fledgling
team of G&J Surveys could take place.
Leica Geosystems were enthusiastic for this to happen and the hill was
surveyed on the 11th August 2008.
Mynydd Graig Goch was surveyed by James Whitworth of Leica
Geosystems using a Leica SmartRover 1200 and two hours of data were gathered in
conditions which can be described as being wet, resulting in a summit height at
that time of 609.72m. These data were
reprocessed by Ordnance Survey resulting in a summit height of 609.75m which
when converted using OSGM15 results in a summit height of 609.8m, which is higher
than the minimum 2000ft (609.6m) height required
for Hewitt status.
 |
| The Leica SmartRover 1200 set-up position at the summit of Mynydd Graig Goch |
The reclassification of this hill from Sub-Hewitt to Hewitt status
was accepted by the list author and its new classification augmented in to the
listing of the Hewitts in August 2008 and its newly acquired summit height and
its ramifications was announced via a press conference on the 19th
September 2008.
The full details for the hill are:
Name: Mynydd Graig
Goch
OS 1:50,000 map: 115,
123
OS 1:25,000 map: 17,
254
Summit Height: 609.8m (converted
to OSGM15)
Summit Grid Reference:
SH 49732 48518
Bwlch Height: 539m (as
listed in the Hewitts)
Bwlch Grid Reference:
SH 50929 48808 (as listed in the Hewitts)
Drop: 71m (as listed
in the Hewitts)
Myrddyn Phillips (June 2019)
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