Penmaen Mawr (SH 698 755) Sub-Trichant addition
There has been an addition to the listing of Y Trichant initiated by a survey with
the Trimble GeoXH 6000, with subsequent confirmation through analysis of LIDAR data by Aled Williams. Y
Trichant is the title for the hills in the 300m height band of the Twmpau (thirty welsh metre prominences
and upward) and takes in all Welsh hills at or above 300m and below 400m in
height that have a minimum 30m of drop, with the introduction to the re-naming
of this list appearing on Mapping Mountains on the 13th May 2017.
The details relating to this hill’s addition as a Sub-Trichant are retrospective as its new classification was
dependent upon a survey with the Trimble GeoXH 6000 which was conducted on the 14th
July 2016.
The hill did not appear in the sub category that accompanied
the original Welsh P30 lists when published on Geoff Crowder’s v-g.me website,
this sub category has now been standardised and named the Sub-Trichant and comprises all Welsh hills at or above 300m and
below 400m in height with 20m or more and below 30m of drop.
The hill was not classified prior to the survey
with the Trimble as much of the hill has been quarried and as is the norm in
such circumstances there is a lack of uppermost contour lines on current
Ordnance Survey maps. But at one stage
it was a part of a relatively substantial hill that had a prominence in excess
of 100m and a 1,550ft (472m) summit map height shown on the Ordnance Survey
Popular and New Popular One-Inch maps, with this height also appearing on the
Ordnance Survey Six-Inch map published in 1888, and therefore it would have met
the criteria specified for inclusion to the Humps
and the main Y Pedwarau
listings. The subsequent quarrying has
produced two distinct summits with the details given in this post relating to
the higher of the two summits that are both known by the same name. The hill no longer meets the qualification
for these two listings as its summit has been quarried and current Ordnance
Survey maps only give it an uppermost 370m contour line. However, quarried areas are usually given no
contour lines on Ordnance Survey maps indicating that the ground is or has been
in flux, and photographic and map study by Aled indicated that the remaining
high point was substantially higher than 370m.
The name of the hill is Penmaen Mawr and it is a part of the Carneddau
range with its Cardinal Hill being Tal y Fan (SH 729 726) and is placed in the
Region of North Wales (Region A, Sub-Region A1). The hill is situated to the south of the A 55
road and is positioned between the towns of Llanfairfechan to its west and Penmaenmawr
to its east, with the latter taking its name from the hill.
The hill can be easily accessed from a minor road to the
south of the summit that reaches over 260m in height, a public footpath heads
north from just below the high point of this minor road and joins a track
designated a bridleway that contours around the southern slopes of the upper
section of the hill. A large section of
the land above the bridleway is designated open access land and the summit of
Penmaen Mawr is close to this.
The full details for the hill are:
Cardinal Hill: Tal y
Fan
Summit Height: 390.4m
(converted to OSGM15)
Name: Penmaen Mawr
OS 1:50,000 map: 115
Summit Grid Reference:
SH 69865 75523
Drop: 26.9m (converted
to OSGM15)
 |
| Penmaen Mawr (SH 698 755) is now included in the listing of Sub-Trichant hills |
Myrddyn Phillips (September 2017)
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