Hill Lists – Cymru / Wales – 200m Twmpau updates – Mynydd Epynt

The first list to the Welsh 200m P30 hills was published on Geoff Crowder’s website v-g.me in 2000; this list preceded the list of TuMPs by nine years, the list proved a very useful resource for the TuMP compilation for this category of hill.

The Welsh 200m P30 list documents all hills in Wales that are at or above 200m in height and are below 300m in height, to qualify for the main list each hill requires a minimum of 30m of prominence.

The hills listed below are updates to the Welsh 200m P30 list originally published on Geoff Crowder's website.  To see the original list click {here}

The original published list had a Sub-List which was entitled ‘Hills to Survey’.  This list consisted of all hills in Wales in the stipulated height band that have a minimum of 20m of prominence, but do not meet the minimum 30m of prominence to enter the main list, according to Ordnance Survey map spot heights and contours.  Nowadays the standard Sub-List takes in all hills that have a minimum of 20m of prominence.  However, the Hills to Survey Sub-List discounted hills whose map spot heights gave a drop value of less than 30m, but more than 20m.  By doing so, the only hills that were Sub-Listed were those that map values dictated stood a chance of entering the main list, for example; if a hill had a summit spot height of 250m and a bwlch spot height of 221m, it was not listed in the Hills to Survey Sub-List as with 29m of drop I thought it did not stand a chance of main list qualification.

 

When compiling the Sub-List I was measuring many hills for P30 status using a basic levelling technique, please click {here} for more information concerning this.  I now know that Ordnance Survey spot heights have a standard margin of uncertainty of + / - 3m associated with their accuracy.  Therefore many hills that were not listed in the original Sub-List may have sufficient drop to enter the main list.  Because of this the Sub-List has been altered to include all hills that have a minimum of 20m of drop but are not known to attain the minimum 30m of drop to enter the main list.

The hills listed below are those major amendments to the original Welsh 200m P30 list as it appears on Geoff’s website.  There are many hills that have been promoted from the Hills to Survey Sub-List to the main list, whilst there are many additions to the Sub-List now that it has been standardised to include all 20m minimum but below 30m drop hills.

When the 200m P30 list was first published it was the first to this category of hills and in some way it and its other 100m height band lists paved the way for Clem’s data that later appeared on the RHB file database and then for the TuMPs listing by Mark Jackson.

As well as the first P30 list to this height band the list is now the first to include a comprehensive Sub-List.

TuMP baggers beware; as the main list also includes P30’s not listed by Mark Jackson, so if you want to visit all P30’s you’ll have to include some non TuMPs to do so.

The list will be updated on a weekly basis and will be done so through each Group category, starting from the north and working south.  The twentieth Group is Mynydd Epynt.

Mynydd Epynt

 

North of the Afon Gwydderig at SN 770 342 to SN 871 299 and then north of the Afon Wysg (River Usk) to SO 127 211, continuing west of small stream to bwlch at SO 142 225 and the Afon Llynfi to Llyn Syfaddan (Llangors Lake) and the Afon Llynfi to SO 178 389, continuing south of the Afon Gwy (River Wye) to SO 034 515 and the Afon Irfon to SN 893 459 and the Afon Cledan to bwlch at SN 840 432, continuing east from bwlch and the Afon Gwyddon and Afon Bran to SN 770 342.  Bordering with Y Mynydd Du, Fforest Fawr and Bannau Brycheiniog to the south, Mynyddoedd Duon to the east, Fforest Glud and the Elenydd to the north and the Elenydd to the west. 

    

Twmpau - 200m updates

Pt. 243m    243m    SO 126 320

This hill was originally listed with a part invented name of Moel Meiadd, as this is wholly  unnecessary the name of the hill has reverted to the Pt notation until further enquiry can take place.  The hill qualifies for the Welsh 200m P30 list as it has a 243m summit spot height on Ordnance Surveys maps and a bwlch spot height of 213m on the Ordnance Survey enlarged Geograph map.  These values give this hill 30m of drop.

Sub-Twmpau - 200m updates

Pt. 289m    289m    SN 927 456

Another hill name that follows the Pt notation as no appropriate name is known for it by the blog author.  As the hill has a 263m spot height at the bwlch on the Ordnance Survey enlarged Geograph map at SN 929 454, it gives this hill 26m of drop.

Pt. 256m    256m    SO 097 344

With a summit spot height of 256m and a bwlch spot height of 235m this hill has 21m of drop and therefore qualifies for the Welsh 200m Sub-P30 list.  The height of the bwlch is given as a 235m spot height on the Ordnance Survey 1:50,000 map at SO 097 346 and as a 235m spot height on the Ordnance Survey enlarged Geograph map at SO 098 347.

Coetgae Fawr    213m    SO 046 495

This hill’s bwlch contouring is between c 190m – c 200m and as its valley to valley contours are placed quite near to one another, the height of the bwlch has been estimated as c 192m, giving this hill c 21m of drop.

Pt. 282m    282m    SO 094 412

With a summit spot height of 282m and bwlch contouring between c 260m – c 270m with an estimated bwlch height of c 262m, this hill has c 20m of drop.

Pt. 276m    276m    SN 987 491

As no appropriate name is known for this hill by the blog author it follows the Pt notation.  The bwlch contouring is between c 250m – c 260m with the bwlch centred on SN 989 491 and estimated to be c 256m high, giving this hill c 20m of drop.

Next update due on the 1^st September 2014