Mapping Mountains – Hill Reclassifications – Hewitts

Foel Penolau (SH 661 347 and SH 661 348) – Sub-Hewitt reclassified to Hewitt

This is one in a series of retrospective Hill Reclassification posts that detail hills whose status has altered in the listing of the Welsh Hewitts (an acronym for Hill in England, Wales or Ireland over Two Thousand feet high).  These reclassification posts will give details of hills where I have direct association with their change of status, and they will tie in with a forthcoming Change Register giving detail to this list and its alterations since first publication.

The listing of Welsh Hewitts was published in booklet format by TACit Tables in February 1997 and entitled The Hewitts and Marilyns of Wales.  This list evolved out of The Absolute Summits of England and Wales which were known as the Sweats (an acronym for Summits in Wales and England Above Two-thousand FEET) and which was published by Cicerone Press in 1992 in the book entitled The Relative Hills of Britain.  The list compiler for the Hewitts and the preceding Sweats is Alan Dawson.

When the Welsh Hewitts list was published in booklet format there were 137 qualifying hills listed with their criteria being any Welsh hill at or above 2000ft (609.6m) in height with 30m minimum drop, accompanying the main list are two sub category’s entitled SubHewitts, with the two sets of criteria being any Welsh hill at or above 600m and below 2000ft (609.6m) in height that have a minimum drop of 30m and any Welsh hill at or above 2000ft (609.6m) in height with 20m or more and below 30m of drop.

The Hewitts and Marilyns of Wales by Alan Dawson

The details for the hill reclassification appear below:

The name of the hill is Foel Penolau, and it is adjoined to the Rhinogydd group of hills, and it is positioned with the A496 road to the west and the A470 road and the village of Trawsfynydd towards the east.

Foel Penolau (SH 661 347 & SH 661 348)

Prior to this hill’s reclassification to Hewitt status it was listed as a Sub-Hewitt with 26m of drop based on the 614m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, with also a 614m twin top appearing on the Ordnance Survey Vector Map Local hosted on the Geograph website which is entitled the Interactive Coverage Map, and the 588m spot height that was considered to be positioned at the bwlch and appears on the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.

As the contouring on the area of this hill’s bwlch suggested its critical position was nearer the boulder field at the base of this hill’s south-western cliff face it was prioritised for a GNSS survey.

Subsequently the GNSS survey took place on the 17^th November 2018 with a more detailed bwlch survey taking place on the 26^th November 2018.  The hill was surveyed by Myrddyn Phillips and Aled Williams on the 17^th and by Myrddyn Phillips on the 26^th using a Trimble GeoXH 6000 to determine the summit and bwlch height and also its drop value, resulting in the following summary:

1^st summit survey 17.11.18:  614.379m at SH 66145 34774

2^nd summit survey 17.11.18:  614.380m at SH 66184 34832

Bwlch survey 17.11.18:  582.482m at SH 66099 34735

 

With 1mm difference between the northern and southern summits the Trimble GeoXH 6000 was unable to split these tops.  Therefore, with a surveyed summit height of 614.4m and with a surveyed bwlch height of 582.5m, these values give this hill 31.9m of drop, with these details being forwarded to the list author.

The Trimble GeoXH 6000 set-up position on the northerly summit of Foel Penolau

The reclassification of this hill from Sub-Hewitt to Hewitt status was accepted by the list author and its new classification augmented in to the listing of the Hewitts in November 2018.

The full details for the hill are:

Name:  Foel Penolau

OS 1:50,000 map:  124

OS 1:25,000 map:  18

Summit Height:  614.4m (converted to OSGM15)

Summit Grid Reference:  SH 66187 34835 & SH 66148 34777 (as listed in the Hewitts)

Bwlch Height:  582.5m (converted to OSGM15)

Bwlch Grid Reference:  SH 6609 3473 (as listed in the Hewitts)

Drop:  31.9m

Myrddyn Phillips (July 2019)