Craig y Garreg Lwyd (SH 730 427) – 400m Sub-Pedwar reinstated
to Pedwar
There has been a re-instatement of a hill to the listing of the Y Pedwarau – The 400m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Leica GS15 survey conducted by John Barnard and Graham Jackson.
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| Craig y Garreg Lwyd (SH 730 427) |
The criteria for the list that this re-instatement applies to are:
Y Pedwarau – The 400m Hills of Wales. Welsh hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are five categories of sub hills, with this hill being reclassified from 400m Sub-Pedwar status. The criteria for this sub category being all Welsh hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.
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| Y Pedwarau - The 400m Hills of Wales by Myrddyn Phillips and Aled Williams |
The name the hill is listed by is Craig y Garreg Lwyd, and it is adjoined to the Arenig Fach group of hills, which are situated in the central part of North Wales (Region C1, Sub-Region C1A), and it is positioned with a minor road to its north-west, the B4391 road to its south and the B4407 road to its east, and has the village of Ffestiniog towards the west south-west.
When the original 400m height band of Welsh P30 hills compiled by Myrddyn Phillips was published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a non-interpolated c 470 summit height, with its inclusion based on a basic levelling survey conducted by Myrddyn Phillips, resulting in 99ft/30.2m of drop.
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| Extract from the Ordnance Survey 1:25,000 Explorer map |
After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 35m of drop, based on the 478m summit spot height and the 443m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, and these are the details given the hill when the 1st edition of the Y Pedwarau, now co-authored by Myrddyn Phillips and Aled Williams was published by Europeaklist in May 2013.
However, it was not until a survey with the Trimble GeoXH 6000 that more accurate numerical data could be given this hill. This survey resulted in a 473.4m summit height and a 443.5m bwlch height, with these values giving this hill 29.9m of drop and its reclassifcation to 400m Sub-Pedwar status.
Therefore, the re-instatement of this hill to Pedwar status is due to a Leica GS15 survey, resulting in a 473.8m summit height and a 443.6m bwlch height, with these values giving this hill 30.2m of drop, which is sufficient for it to be classified as a Pedwar.
The full details for the hill are:
Group: Arenig Fach
Name: Craig y Garreg Lwyd
OS 1:50,000 map: 124
Summit Height: 473.8m (converted to OSGM15)
Summit Grid Reference: SH 73043 42743
Bwlch Height: 443.6m (converted to OSGM15)
Bwlch Grid Reference: SH 73220 42799
Drop: 30.2m
For the additions, reclassifications and deletions to Y Pedwarau – The 400m Hills of Wales reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:
Y Pedwarau – 400m Sub-Pedwarau
Y Pedwarau – 390m Sub-Pedwarau
Myrddyn Phillips and Aled Williams (October 2017)
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