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

Pt. 366m (SJ 207 568 & SJ 205 575) – 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 hill is being listed by the point (Pt. 366m) 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 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 B5430 road to its south and minor roads to its east, north and west, and has the town of Yr Wyddgrug (Mold) towards the north north-east.

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

When the P30 lists were standardised, and interpolated heights and drop values also included, this hill was listed with an estimated c 19m of drop based on an estimated c 366m summit height and an estimated c 347m bwlch height, with both based on interpolation of 5m contouring with a small 365m uppermost contour given to two summits and contouring between 345m – 350m for the bwlch that appear on 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 the Magic Maps website.

The WalkLakes website hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available Ordnance Survey maps and for this hill a 366m spot height is given to the more northerly of the two summits which is positioned at SJ 205 575.

Extract from the WalkLakes website

Another resource available online is the interactive mapping originated from Ordnance Survey data hosted on the Magic Maps website.  This mapping shows the two summits with 366m spot heights, with the more southerly positioned at SJ 207 568, which for listing purposes is regarded as the prioritised summit.

Extract from the Magic Maps 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 amended and estimated as c 346m based on interpolation of 5m contouring between 345m – 350m.

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 366m summit height and an estimated c 346m bwlch height, with these values giving this hill an estimated c 20m 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:  Pt. 366m

OS 1:50,000 map:  117

Summit Height:  366m (spot heights)

                                                           

Summit Grid Reference:  SJ 20774 56802 & SJ 20505 57502 (spot heights)

Bwlch Height:  c 346m (interpolation)

Bwlch Grid Reference:  SJ 20750 57920 (interpolation)

Drop:  c 20m (spot height summits and interpolated bwlch)

Myrddyn Phillips (November 2020)