Moel Tryfan (SH 517 559) - 400m Sub-Pedwar addition
There has been a new 400m Sub-Pedwar added to the list by analysis
of LIDAR data by Aled Williams. The hill
is one that Aled first proposed as a prospective 400m Sub-Pedwar approximately two
years ago and it then waited to be Trimbled, but as of now this has not
occurred and in the meantime as LIDAR data is proving highly accurate we are
using the data that Aled has obtained.
The 400m Sub-Pedwarau are the Welsh hills at or above 400m and below 500m in
height with a drop between 20m and below 30m.
The hill is situated in the group of hills known
as Moel Hebog with its Cardinal Hill being Mynydd Mawr (SH 539 546) and is
placed in the Region of North Wales (A-1).
The hill is positioned above the small communities of Nantlle to its
south and Groeslon towards its west, and is immediately above the remains of
the Moel Tryfan Slate Quarry and the Alexandra Slate Quarry, and can be easily
accessed from either a track leading up through the slate spoil from the south
or a track from the north-west that contours round the northerly part of the
hill before heading toward its summit.
The name of the hill is Moel Tryfan and this name
is shared with its higher adjacent summit positioned at SH 515 561 which is
429.0m in height. The hill is of
interest as it is only now listed as a 400m Sub-Pedwar through the quarrying
activities of past years, as the quarry now separates the 400m Sub-Pedwar from its 429.0m
higher adjacent peak which is already listed as a Pedwar. In essence the new 400m Sub-Pedwar consists of a
man-made natural summit as the quarrying activity has created two new bylchau
and split the summit plateau of Moel Tryfan in two parts.
The current Ordnance Survey map details give this
hill an uppermost 400m ring contour that has no spot height and bwlch contours
that are not continuous due to the remains of the quarry, and which are either
between 380m – 390m or 390m – 400m.
Aled’s analysis of LIDAR data gives the hill the
following details:
Moel
Tryfan
Summit
Height: 405.4m
Summit
Grid Reference: SH 51781 55927
Bwlch
Height: 383.9m
Bwlch
Grid Reference: SH 51523 55909
Drop: 21.5m
With
the alternate bwlch position to the north at SH
52022 56309 as 372.9m in height.
Therefore, the 405.4m LIDAR data produced for the summit position
at SH 51781 55927 and the 383.9m LIDAR data produced for the bwlch position at
SH 51523 55909 is sufficient for this hill to be included in the list of 400m Sub-Pedwarau with 21.5m of drop, and therefore Moel Tryfan is included in the
listing of 400m Sub-Pedwar hills and the list of the Y Pedwarau will be updated
accordingly. The list of Pedwar hills is
available from the Haroldstreet website.
The full details for the hill are:
Cardinal Hill: Mynydd
Mawr
Summit Height: 405.4m
(LIDAR data)
Name: Moel Tryfan
OS 1:50,000 map: 115
Summit Grid Reference:
SH 51781 55927
Drop: 21.5m (LIDAR
data)
The list of additions, reclassifications and deletions from
the 400m Sub-Pedwar list since the 1st edition of the Y Pedwarau was
published by Europeaklist are as follows:
400m SUB-PEDWAR ADDITIONS
Moel Tryfan (LIDAR data) (SH 517 559) 21.5m drop
Pt. 422.3m (converted to OSGM15) (SO 073 822) Pedwar reclassified to 400m Sub-Pedwar with 29.0m drop
Pt. 407.7m (converted to OSGM15) (SO 180 692) Pedwar reclassified to 400m Sub-Pedwar with 28.3m drop
400m SUB-PEDWAR RECLASSIFICATIONS
Pt. 499.5m (converted to OSGM15) (SH 665 310) 400m Sub-Pedwar reclassified to Pedwar with 30.3m drop
400m SUB-PEDWAR DELETIONS
 |
| Looking across at the man-made northern bwlch with the lower slopes of the new 400m Sub-Pedwar of Moel Tryfan on the right |
Myrddyn Phillips and Aled Williams (December 2016)
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