Sunday, 2 January 2022

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

 

Pt. 385m (SH 627 326) – 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 13th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1st January 2022. 

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

The hill is being listed by the point (Pt. 385m) notation as an appropriate name for it either through local enquiry and / or historic research has not been found by the author, and it is adjoined to the Y Llethr group of hills, which are situated in the western part of North Wales (Region A, Sub-Region A2), and it is positioned with minor roads to its west and south, and the B4573 road and the A496 road farther to its west, and has the village of Harlech towards the west south-west. 

When the original 300m height band of Welsh P30 hills were 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. 

Extract from the Harvey 1:25,000 Superwalker map to the Rhinogydd

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 35m of drop, based on the 386m summit spot height that appears on the Harvey 1:25,000 Superwalker map to the Rhinogydd and an estimated c 351m bwlch height, based on interpolation of 10m contouring between 350m – 360m that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

The details for this hill were subsequently 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 385m summit spot height and a 351m bwlch spot height.  This re-assessment resulted in the drop value being amended to 34m. 

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 385m summit height and a 351m bwlch height, with these values giving this hill 34m of drop, which is sufficient for it to be classified as a Trichant. 

 

The full details for the hill are: 

Group:  Rhinogydd 

Name:  Pt. 385m 

OS 1:50,000 map:  124

Summit Height:  385m (spot height)                                                           

Summit Grid Reference:  SH 62790 32628 (hand-held GPS via DoBIH) 

Bwlch Height:  351m (spot height) 

Bwlch Grid Reference:  SH 62933 33128 (spot height) 

Drop:  34m (spot height summit and bwlch) 

 

Myrddyn Phillips (January 2022)

 

 

 

 

 

 

 

No comments: