Mapping Mountains – Hill Reclassifications – Y Trichant

Pt. 368.9m (SH 991 412) – Sub-Trichant addition

There has been confirmation of an addition of a hill to the list of the Y Trichant, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis, and a Trimble GeoXH 6000 summit survey conducted by Myrddyn Phillips, with the latter taking place on the 25^th October 2014.

Pt. 368.9m (SH 991 412)

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

Y Trichant – 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.

As I do not know an appropriate name for the hill either from historic documentation or local enquiry it is being listed under the point (Pt. 368.9m) notation, and it is adjoined to the Arenig group of hills, which are situated in the central part of North Wales (Region A, Sub-Region A3), and it is positioned with the A494 road to its south-east, and has the town of Y Bala towards the 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 not included in the Hills to be surveyed sub list that accompanied the main P30 list, as it did not 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 and it was listed with 25m of drop, based on the 369m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 344m bwlch spot height that appears on the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.

Extract from the Ordnance Survey Vector Map Local hosted on the Geograph website

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR image of Pt. 368.9m (SH 991 412)

The confirmation of the addition of Pt. 368.9m to Sub-Trichant status is due to LIDAR analysis, resulting in a 368.9m summit height and a 344.2m bwlch height, with these values giving this hill 24.7m of drop which is sufficient for it to be classified as a Sub-Trichant.

The full details for the hill are:

Group:  Arenig

Name:  Pt. 368.9m

OS 1:50,000 map:  125

Summit Height:  368.9m (LIDAR)

Summit Grid Reference:  SH 99136 41259 (LIDAR)

Bwlch Height:  344.2m (LIDAR)

Bwlch Grid Reference:  SH 99216 41144 (LIDAR)

Drop:  24.7m (LIDAR)

Myrddyn Phillips (November 2019)