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

Pt. 346m (SH 987 631) – Sub-Trichant addition

There has been confirmation of 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 hill is being listed by the point (Pt. 346m) 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 Mynydd Hiraethog group of hills which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is enclosed by minor roads with the B5435 road to its south-west and the A543 road to its north, and has the town of Dinbych (Denbigh) towards the east 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 sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated against the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.  This mapping had many spot heights not shown on other publicly available Ordnance Survey maps and for this hill it showed a 346m summit spot height and when coupled with the estimated c 321m bwlch height which was based on interpolation of 10m contouring between 320m – 330m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, it gave this hill an estimated c 25m of drop. 

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

The details for this hill were re-assessed when the OS Maps website became available online.  This is the replacement for OS Get-a-map and has contours at 5m intervals which are proving consistently more accurate compared to the 5m contours that sometimes appear on Ordnance Survey 1:25,000 Explorer maps and used to appear on the online Vector Map Local.  This re-assessment resulted in the estimated bwlch height for this hill remaining the same at c 321m, with this based on interpolation of 5m contouring between 320m – 325m.

Therefore, the confirmation of the addition of this hill to Sub-Trichant status is due to detail derived from contemporary maps produced from Ordnance Survey data, resulting in a 346m summit height and an estimated c 321m bwlch height, with these values giving this hill c 25m of drop, which is sufficient for it to be classified as a Sub-Trichant.

The full details for the hill are:

Group:  Mynydd Hiraethog

Name:  Pt. 346m

OS 1:50,000 map:  116

Summit Height:  346m (spot height)

Summit Grid Reference:  SH 98793 63125 (spot height)

Bwlch Height:  c 321m (interpolation)

Bwlch Grid Reference:  SH 99042 63253 (interpolation)

Drop:  c 25m (spot height summit and interpolated bwlch)

Myrddyn Phillips (September 2020)