Monday 23 April 2018

Mapping Mountains – Hill Reclassifications – Major Mountains of Britain and Ireland



Moel Siabod (SH 705 546) – Major deletion

This is the second of two Hill Reclassification posts that give detail to a hill whose status has been altered in the listing of the Major Mountains of Britain and Ireland through map study and / or surveys that I have conducted.

Moel Siabod (SH 705 546)

The post detailing this hill’s addition to the Majors list was retrospective as it appeared on Mapping Mountains on the 21.04.18 with the hill having been added to the list in January 2016, whilst the deletion of this hill from Major status is due to a survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips coupled with LIDAR analysis conducted for the bwlch by Aled Williams and independently by Myrddyn Phillips, with the author of this list; Mark Trengove being present during the survey of this hill’s summit.

This list was first published in a downloadable leaflet format by Europeaklist in February 2010 and entitled The Major Mountains of Britain and Ireland, its author; Mark Trengove originally listed 119 qualifying hills with their criteria being any British and Irish hill that has 600m or more of drop, with these comprising 82 hills in Scotland, 25 hills in Ireland, 7 hills in Wales, 4 hills in England and 1 hill in the Isle of Man, with a further five Scottish hills listed that fail to qualify for this list by 10m or less of drop.  The total was revised to 120 hills with the addition of this hill, and which now reverts to its original total of 119 hills with its deletion.

The Major Mountains of Britain and Ireland by Mark Trengove


The details for the deletion appear below:

There has been a deletion to the listing of the Major Mountains of Britain and Ireland due to a survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips with the bwlch survey taking place on the 17.09.17 and the summit survey taking place on the 11.03.18, coupled with LIDAR analysis for the bwlch conducted by Aled Williams and independently by Myrddyn Phillips, with the author of this list; Mark Trengove being present during the survey of this hill’s summit.

Gathering data at the critical bwlch of Moel Siabod

Gathering data at the summit of Moel Siabod

The name of the hill is Moel Siabod and prior to this survey and LIDAR analysis it was listed with 600m of drop, which is the minimum drop value required for Major status.  This was based on the 872m summit spot height that is adjoined to a triangulation pillar and the 272m spot height that appears at the bwlch on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

The hill is adjoined to the Moelwynion range of hills and is situated overlooking the A 5 road to its north-east, the A 4086 road to its north-west and the A 498 road to its west, and has the small community of Capel Curig to its north north-east.

The deletion of this hill from Major status was accepted by Mark Trengove and announced in his photo blog on the Relative Hills of Britain Facebook page on the 14.03.18, with this deletion augmented in to the listing of the Major Mountains of Britain and Ireland resulting in the total reverting to 119 qualifying hills.


The full details for the hill are:

Name:  Moel Siabod

Summit Height:  872.2m (converted to OSGM15)

OS 1:50,000 map:  115

OS 1:25,000 map:  18

Summit Grid Reference:  SH 70524 54631

Drop:  599.9m (converted to OSGM15) (Trimble GeoXH 6000 summit and bwlch) 599.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)


Myrddyn Phillips (April 2018)




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