Friday 23 October 2020

Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales


Coed y Fedw (SJ 201 613) – Sub-Trichant addition

There has been an addition to the list of Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data.

The criteria for the list that this addition applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Coed y Fedw, and it is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with the A494 road to its north-west and minor roads to its south and east, and has the village of Gwernymynydd towards the north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for this sub category. 

After the P30 lists were standardised, and interpolated heights and drop values also included, and the lists updated, this hill was listed with an estimated c 24m of drop based on an estimated c 317m summit height and an estimated c 293m bwlch height based on interpolated detail from the Ordnance Survey 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

Since publication of these P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey 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 are current and digitally updated such as the mapping on the WalkLakes website, and it is this mapping that gives this hill a 318m summit spot height.

Extract from the WalkLakes website

The details for this hill were also re-assessed against 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.  This resulted in its bwlch height being listed as c 294m based on interpolation of 5m contouring between 290m – 295m.

Therefore, the addition of this hill to Sub-Trichant status is due to detail on contemporary maps produced from Ordnance Survey data, resulting in a 318m summit height and a c 294m bwlch height, with these values giving this hill c 24m of drop, which is sufficient for it to be classified as a Sub-Trichant.


The full details for the hill are:

Group:  Moel y Gamelin

Name:  Coed y Fedw

OS 1:50,000 map:  117

Summit Height:  318m (spot height)

Summit Grid Reference:  SJ 20180 61372 (spot height)

Bwlch Height:  c 294m (interpolation)

Bwlch Grid Reference:  SJ 20367 61266 (interpolation)

Drop:  c 24m (spot height summit and interpolated bwlch)


Myrddyn Phillips (October 2020)









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