Chwarel Graig Ddu (SH 725 455) – Uchaf
addition
There has been an addition to the listing of The Welsh Highlands – Uchafion Cymru, with the summit height, bwlch height
and their locations, the drop and status of the hill derived from detail on
contemporary maps.
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| Chwarel Graig Ddu (SH 725 455) |
The criteria for the list that this addition applies to are:
The Welsh Highlands –
Uchafion Cymru
– This is the revised draft title for the Welsh 500m P15s list that takes
in all hills in Wales at or above 500m in height with 15m minimum drop. The list is co-authored by Myrddyn Phillips
and Aled Williams with the Introduction to the list being published on Mapping Mountains
in November 2015 and an update relating to the list appearing on Mapping Mountains on the 19th June 2019.
 |
| The Welsh Highlands - Uchafion Cymru by Myrddyn Phillips and Aled Williams |
The name the hill is listed
by is Chwarel Graig Ddu, and it is adjoined to the Arenig Fach group of hills, which are situated in the north-western part of
North Wales (Region A, Sub-Region A2), and it is positioned with the A470 road to its west and the B4391 road
to its south, and has the town of Blaenau Ffestiniog towards the west.
This hill was not included in the original list of
Welsh 500m P15s that later became known as Yr
Uchafion and latterly as The Welsh
Highlands – Uchafion Cymru, as because it is a part of a working quarry the
contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map do
not show any spot heights or contours, therefore the hill seemed not to exist.
 |
| Extract from the Ordnance Survey 1:25,000 Explorer map |
Since the original compilation of this list there
have been a number of maps made available online. Some of these are historic such as the series
of Six-Inch maps on the National Library of Scotland website. Whilst others were digitally updated such as
the Ordnance Survey Vector Map Local that was hosted on the Geograph website
and which was entitled the Interactive Coverage Map, whilst others are current
and digitally updated such as the interactive mapping on the Magic Maps and
WalkLakes websites.
One of the resources recently available online is
the mapping on the OS Maps website. This
is the replacement for OS Get-a-map and until recent times had contours at 5m
intervals which were proving consistently more accurate compared to the 5m
contours that sometimes appear on the Ordnance Survey 1:25,000 Explorer map and
used to appear on the online Vector Map Local.
Although the mapping on the OS Maps website no longer has contours at 5m
intervals, such contours are represented on other mapping available online and
for this hill this mapping has an uppermost 610m ring contour and bwlch
contouring between 590m – 595m, with these contours giving this hill a drop
value exceeding the minimum 15m to qualify for this list.
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| Extract from the online map showing 5m contouring |
The hill has subsequently been inspected from
adjacent hillsides and its validity confirmed and as a quarry road passes over
its summit area it is considered solid and stable.
Therefore, the addition of this hill to Uchaf
status is due to detail on contemporary online mapping with a subsequent
inspection from adjacent hillsides undertaken to confirm its validity, resulting
in a 613m summit height and a 592m bwlch height, with these values giving this
hill 21m of drop, which is sufficient for it to be classified as an Uchaf.
The full details for the hill are:
Group: Arenig Fach
Name: Chwarel Graig
Ddu
OS 1:50,000 map: 115
Summit Height: 613m
Summit Grid Reference:
SH 72505 45533
Bwlch Height: 592m
Bwlch Grid Reference:
SH 72456 45744
Drop: 21m
For the additions, deletions and reclassifications to The Welsh Highlands – Uchafion Cymru
reported on Mapping Mountains please consult the following Change Registers:
The Welsh 500m P15s (Yr Uchafion)
The Welsh 500m P15s (Yr Uchafion) – 500m Subs
The Welsh 500m P15s (Yr Uchafion) – 490m Subs
The Welsh 500m P15s (Yr Uchafion) – Double Subs
Myrddyn Phillips and Aled Williams (June 2022)
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