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

 

Foel (SN 680 459) – Sub-Trichant reclassified to Trichant 

There has been a reclassification 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 reclassification 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 13^th May 2017. 

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

The name the hill is listed by is Foel and it is adjoined to the Elenydd group of hills, which are situated in the central part of the Mid and West Wales Region (Region B, Sub-Region B2), and it is positioned with minor roads to its west, south and east, and has the A482 road farther to its south-west and the village of Pumsaint towards the south south-west. 

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

When 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 an estimated c 32m of drop, based on the 377m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and the 1:25,000 Explorer map and an estimated c 345m bwlch height based on interpolation of 10m contouring between 340m – 350m that appears on the Ordnance Survey 1:25,000 Explorer map. 

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

Since publication of the P30 lists of 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 old Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available maps and for this hill it had a 345m bwlch spot height positioned at SN 68115 46192, and when coupled with the 377m summit spot height gave this hill 32m of drop. 

The details for this hill were subsequently 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 mapping had bwlch contouring between 345m – 350m with interpolation suggesting an estimated c 348m bwlch height, which when coupled with the 377m summit spot height would give this hill an estimated c 29m of drop.  However, for now the hill remains listed with 32m of drop. 

Extract from the OS Maps website

Therefore, the reclassification of this hill from Sub-Trichant status is due to detail on contemporary maps produced from Ordnance Survey data, resulting in a 377m summit height and a 345m bwlch height, with these values giving this hill 32m of drop, which is sufficient for it to be classified as a Trichant. 

 

The full details for the hill are: 

Group:  Elenydd 

Name:  Foel 

OS 1:50,000 map:  146

Summit Height:  377m (spot height)                                                           

Summit Grid Reference:  SN 68012 45933 (hand-held GPS via DoBIH) 

Bwlch Height:  345m (spot height) 

Bwlch Grid Reference:  SN 68115 46192 (spot height) 

Drop:  32m (spot height summit and bwlch) 

 

Myrddyn Phillips (September 2021)