Mapping Mountains – Hill Reclassifications – 30-99m Twmpau

Coed Bodlondeb (SH 779 781) – 30-99m Sub-Twmpau reclassified to 30-99m Twmpau

There has been a reclassification to the Twmpau (thirty welsh metre prominences and upward) list with this hill being included in the 30-99m Twmpau height band.  Accompanying all the 100m height band of hills within the Twmpau are sub lists with the one attached to this list being entitled the 30-99m Sub-Twmpau.  The details relating to this hill’s addition are retrospective as its inclusion as a P30 was reported on Mapping Mountains on the 17^th December 2015.

The criteria for 30-99m Twmpau status is all Welsh hills at or above 30m and below 100m in height with 30m minimum drop, whilst the criteria for 30-99m Sub-Twmpau status is all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop.

Prior to this hill’s inclusion as a 30-99m Twmpau it was listed with an estimated c 27m of drop based on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps giving the hill an uppermost 50m ring contour and bwlch contouring between 20m – 30m, resulting in an estimated summit height of c 53m and an estimated bwlch height of c 26m.

The hill is positioned in the Carneddau group of hills and is placed in the Region of North Wales (Region A, Sub-Region A1) with its Cardinal Hill being Tal y Fan (SH 729 726) and is situated on the northern outskirts of Conwy with the Afon Conwy to its immediate north and east.

As the name of the hill suggests it is a part of a wood which is made up of deciduous trees and for those wanting to visit permission should be sought as it is not a part of designated open access land.  However, access is relatively easy with public parking available next to where the Offices are marked to the south of the summit on Ordnance Survey maps, and there are a number of paths marked on the map that head up to, or contour around the top of the hill.

The name of the hill is Coed Bodlondeb and it is included as a 30-99m Twmpau as the Ordnance Survey enlarged mapping hosted on the Geograph website has contours at 5m intervals giving the hill an uppermost contour of 55m and bwlch contouring between 20m – 25m.  Therefore the summit is estimated as being c 57m high and the bwlch estimated as being c 23m high, with these values giving this hill c 34m of drop.

Since this hill was originally included in the Twmpau list the summit has been surveyed with the Trimble GeoXH 6000 and the bwlch of the hill has been analysed via LIDAR and the resulting values are given below.

The full details for the hill are:

Cardinal Hill:  Tal y Fan

Name:  Coed Bodlondeb

OS 1:50,000 map:  115

Summit Height:  55.6m (converted to OSGM15)

Summit Grid Reference:  SH 77921 78114

Bwlch Height:  22.9m (LIDAR)

Bwlch Grid Reference:  SH 77852 77725 (LIDAR)

Drop:  32.6m (Trimble summit and LIDAR bwlch)

Gathering data at the summit of Coed Bodlondeb

For details on the summit survey of Coed Bodlondeb

Myrddyn Phillips (July 2017)