Mapping Mountains – Hill Reclassifications – Humps

Mynydd Caerau (SS 890 944) – Subhump addition

This is the thirteenth in a series of Hill Reclassification posts that detail hills whose status has been altered in the listing of the Humps (HUndred Metre Prominences) through map study and / or surveys that I have instigated.

This and forthcoming posts are retrospective as many of these hill reclassifications were initiated from studying the Ordnance Survey enlarged mapping that is hosted on the Geograph website, and for the reclassifications that affected the Humps the email sent to DJM&M was dated 03.10.12 and the details of this hill were then forwarded to Mark Jackson via email on the 04.010.12.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for the reclassification appear below:

There has been a reclassification to the listing of the Humps (HUndred Metre Prominences) due to consulting the Ordnance Survey enlarged mapping that is hosted on the Geograph website, with these details being sent to Mark Jackson on 04.10.12.

Prior to this notification Mark Jackson had listed this hill with c 87m of drop based on the 555m spot height given to a triangulation pillar on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated bwlch height of c 468m based on bwlch contouring at 10m intervals.  However, with a 464m spot height appearing at the bwlch of this hill on the Ordnance Survey enlarged mapping hosted on the Geograph website it meant that when coupled with the 555m summit height it gave this hill 91m of drop, which is sufficient for it to be classified as a Subhump.  Since this notification LIDAR data has become publicly available and analysis of these data by Aled Williams gives this hill just under the 90m of drop required for Subhump status.

Extract from the Ordnance Survey enlarged mapping hosted on the Geograph website showing the 464m spot height at the bwlch of this hill

The hill is adjoined to the Y Cymoedd range of hills and is situated overlooking the A 4107 road to its north and the A 4064 road towards its south-east, with the small communities of Blaengarw and Pontycymer towards the hill’s south-east and Abergwynfi towards the hill’s north.

The addition of this hill to Subhump status was accepted by Mark Jackson and its new classification augmented in to the listing of the Humps on the 01.12.12.

The full details for the hill are:

Name:  Mynydd Caerau

Summit Height:  555m (as listed in the Humps)

OS 1:50,000 map:  170

OS 1:25,000 map:  166

Summit Grid Reference:  SN 89057 94411 (as listed in the Humps)

Drop:  91 (as listed in the Humps)

Myrddyn Phillips (September 2017)