Monday 1 September 2014

Hill Lists – Cymru / Wales – 200m Twmpau updates – Elenydd



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 Twenty First Group is the Elenydd.



Elenydd
 
North and then east of the Afon Wyre at SN 527 699 to bwlch at SN 645 687, continuing east of the Camddwr to the Afon Teifi and Cors Caron at SN 677 622, continuing east and then south of the Afon Teifi to SN 411 401, and east of the Afon Tyweli to SN 445 363 and the Nant Grân to bwlch at SN 419 337 and the Nant Aeron to SN 418 292, continuing south and then east and then north of the Afon Gwili to SN 431 205, continuing north of the Afon Tywi (River Towy) to SN 753 327, continuing north and west of the Afon Brân to SN 811 403, continuing north and west of the Afon Gwyddon to bwlch at SN 840 432, continuing north of the Cledan to SN 893 459 and the Afon Irfon to SO 034 515, continuing west and then south of the Afon Gwy (River Wye) to SN 841 826, continuing south of the Afon Tarrenig to Eisteddfa Gurig at SN 797 841, the Afon Castell to SN 749 807 and the Afon Rheidol to Aberystwyth and the sea at SN 579 808.  Bordering with Pumlumon to the north, Garreg Lwyd, Pegwn Mawr, Gwastedyn Hill and Fforest Glud to the east, Mynydd Epynt, Y Mynydd Du and Mynydd Sylen to the south, Moelfre, Mynydd Bach and the sea to the west.   


Twmpau - 200m updates

Comins Pen-y-banc    299m    SN 675 691

This hill has been promoted from the Sub-List and has had its previously listed name of Allt y Pantyddafad dropped in favour of Comins Pen-y-banc, as the former name was invented by the list author.  Its promotion is based on a summit spot height of 299m appearing on the Ordnance Survey enlarged Geograph map, as this is two metres higher when compared to the hill at SN 656 694 the critical bwlch is now swapped, giving this hill a dramatic increase in its drop value from c 28m to c 92m.  The hill at SN 656 694 is now reclassified from a P30 to a Sub (see below).



Pen Llys    292m    SN 998 584

Another promotion from the Sub-List as with a summit spot height of 292m and a spot height at the bwlch of 262m, this hill has a listed drop of 30m.  The bwlch spot height appears on the Ordnance Survey enlarged Geograph map as SN 995 586.



Pt. c 285m    c 285m    SN 972 529

This hill has been promoted from the Sub-List and has reverted to the Pt. notation for its name as it was previously listed as Llethr-budr, and it is inconclusive if this is the name of the hill as mapping suggests that this name is applicable to a farm to the south of the hill’s summit.  The summit height has been estimated as c 285m and the area of the bwlch has a 252m spot height on the Ordnance Survey enlarged Geograph map.  These values give the hill c 33m of drop.



Pt. 282m    282m    SN 802 424

This hill used to be listed by an invented name of Bryn y Bwlch-Cynnant, this has been dispensed with and it now follows the Pt. notation until a suitable locally known name can be found for it.  This hill is another example where the Ordnance Survey enlarged Geograph map is proving a useful addition to those interested in hill data, as both summit and bwlch have a spot height on this map, where it seems no other map does.  The 251m bwlch spot height appears at SN 803 426, giving this hill 31m of drop.



Comin y Garth    248m    SN 982 548

With a summit spot height of 248m and a bwlch spot height of 218m, this hill is promoted from the Sub-List as it has 30m of drop.  The bwlch spot height appears on the Ordnance Survey enlarged Geograph map at SN 985 554.



Pt. 245m    245m    SN 917 502

This hill was always a prime candidate for promotion from the Sub-List and with an estimated drop of c 33m it has proved so.  The drop value is based on the 245m summit spot height and bwlch contouring between c 210m – c 220m, with the height of the bwlch estimated as c 212m.  The name is another example where the Pt. notation is preferred to its past listed name of Bryn Llwyngwilym, which was partly invented by the list author.



Allt Mes    217m    SN 795 397

Originally listed in the Sub-List this hill is another that was always a prime candidate for promotion to the P30 list.  With bwlch contouring between c 180m – c 190m with an estimated bwlch height of c 184m, this hill has c 33m of drop.



Pt. 208m    208m    SN 735 366

The name of this hill reverts to the Pt. notation as its previously listed name of Banc Llwyn-celyn was partly invented by the list author based on the name of a farm situated just to the south of the hill’s summit.  The bwlch contouring is between c 170m – c 180m and the height of the bwlch has been estimated as c 175m, giving this hill a drop of c 33m, which is sufficient for its promotion from the Sub-List.



Sub-Twmpau - 200m updates

Pt. 297m, Comins Pen-y-banc    297m    SN 656 694

This hill has been re-classified as it was originally listed as a P30.  Its demotion to the Sub-List is based on a summit spot height of 299m appearing on the Ordnance Survey enlarged Geograph map for the hill at SN 675 691, as this is two metres higher when compared to the hill at SN 656 694 the critical bwlch is now swapped, giving this hill a dramatic decrease in its drop value from c 90m to c 27m.  The hill at SN 675 691 is now reclassified from a Sub to a P30 (see above).



Pt. 279m    279m    SN 714 344

Another hill name that follows the Pt notation as no appropriate name is known for it by the blog author.  This hill has two options for its critical bwlch, one north-westward from its summit, and the other south-eastward from its summit.  Thankfully both have spot heights on the Ordnance Survey enlarged Geograph map, with the bwlch at SN 711 346 (north-westward of summit) having a 253m spot height and the bwlch at SN 716 344 (south-eastward of summit) having a 252m spot height.  As each bwlch leads to higher ground the critical bwlch for this hill is placed at the higher of the two bwlch spot heights, giving this hill 26m of drop.



Pt. 207m    207m    SN 664 396

This hill qualifies for the Sub-List as it has a 207m summit spot height and a 181m bwlch spot height, both of which appear on the Ordnance Survey enlarged Geograph map.  These values give this hill 26m of drop.



Pt. 266m    266m    SN 441 329

A triangulation pillar with a flush bracket height of 265.870m is positioned westward of this hill’s 266m summit, whereas its bwlch is positioned eastward of its summit at SN 451 330.  The bwlch has a 241m spot height on the Ordnance Survey enlarged Geograph map, giving this hill 25m of drop.



Allt Lwyd    257m    SN 691 365

This hill qualifies for the Sub-List as it has a 232m spot height that appears at the bwlch on the Ordnance Survey enlarged Geograph map, giving this hill 25m of drop.



Allt Ddu    295m    SN 614 301

With a summit spot height of 295m and a bwlch spot height of 271m at SN 610 304, with the latter appearing on the Ordnance Survey enlarged Geograph map, this hill has a drop of 24m.



Fforest    289m    SN 919 520

The area of this hill’s bwlch has a 264m spot height that appears on the Ordnance Survey enlarged Geograph map.  As it is difficult to ascertain if the position of this spot height is at the critical bwlch the drop value is based on an estimated bwlch height of c 265m, giving this hill a drop of c 24m.



Pt. 237m    237m    SN 639 438

The name of this hill follows the Pt. notation as the blog author does not know an appropriate name for it.  As the summit spot height is 237m and the bwlch contouring is between c 210m – c 220m, with estimation for the bwlch height as c 213m, this hill has a drop of c 24m.



Allt Brynarth    247m    SN 672 710

Another hill whose qualification to the Sub-List is helped because of data from the Ordnance Survey enlarged Geograph map, as a 224m spot height appears on the area of the bwlch on this map at SN 674 707, giving this hill a drop of 23m.



Allt y Wern    229m    SN 633 407

As the bwlch contouring for this hill is between c 200m – c 210m, with an estimated height of c 206m, this hill qualifies for the Sub-List with c 23m of drop.



Pt. 258m    258m    SN 775 733

This hill name follows the Pt. notation as no appropriate name is known for it by the blog author.  The bwlch has a 236m spot height on it that appears on the Ordnance Survey enlarged Geograph map, giving this hill 22m of drop.



Pt. 225m    225m    SN 693 362

As no appropriate name is known for this hill by the blog author it is listed under the Pt. notation.  The Ordnance Survey enlarged Geograph map has a 203m spot height on the area of the bwlch at SN 693 363, giving this hill 22m of drop.



Comin Cefn-poeth    224m    SN 984 522

This hill qualifies for the Sub-List as the Ordnance Survey enlarged Geograph map has a 202m spot height on the area of the bwlch at SN 981 522, giving this hill 22m of drop.



Pt. 240m    240m    SN 432 316

As the blog author does not know an appropriate name for this hill, it is being listed under the Pt. notation.  The 240m summit height appears on the Ordnance Survey 1:50,000 and 1:25,000 mapping, whereas their enlarged Geograph map only has a 239m spot height at SN 433 316.  The bwlch contouring is between c 215m – c 220m and has been estimated as c 218m, giving this hill c 22m of drop.



Pt. 208m    208m    SN 724 664

Another hill whose name is currently following the Pt. notation as no suitable name is known for it by the blog author.  The summit spot height appears on a minor road named ‘Lisburne Road’ that heads westward out of Pontrhydfendigaid.  The bwlch contouring is between c 180m – c 190m, with the bwlch height being estimated as c 186m, giving this hill c 22m of drop.



Pt. 204m    204m    SN 683 649

The spot height at the summit of this hill is very near to a number of buildings that are clearly marked on the Ordnance Survey map.  There is a temptation to use the name of Pen Bryn for this hill, as this name appears close to the summit of the hill.  However, analysis of the map indicates that this name is applicable to the buildings and not the hill, therefore the Pt. notation has been adopted for the name of this hill.  The bwlch contouring is between c 180m – c 190m with the height of the bwlch estimated as c 182m, giving this hill c 22m of drop.  There are two spot heights on the area of the bwlch that appear on the Ordnance Survey enlarged Geograph map, one is 185m at SN 684 654, the other is 182m at SN 683 656, analysis indicates that neither is at the critical bwlch.



Allt Blaen-bydernyn    283m    SN 551 443

The Ordnance Survey 1:25,000 and the enlarged Geograph maps only have an uppermost contour of c 280m, whilst the Ordnance Survey 1:50,000 map has a 289m spot height at SN 551 443.  The old Seventh Series One-Inch Ordnance Survey map has a 947ft (288.6m) spot height at the summit for this hill, this matches the rounded up metric figure on the 1:50,000 map.  However, the Ordnance Survey 1:10,560, New Popular One-Inch and the Historical 1:25,000 maps have a summit spot height of 927ft (282.6m).  It is this figure that is being used for this hill’s height.  The bwlch has a 261m spot height on it that appears at SN 555 439 on the Ordnance Survey enlarged Geograph map, with a 262m spot height appearing on the Ordnance Survey 1:50,000 map at SN 554 439 being considered as positioned too high for the critical bwlch.  The values of 282.6m and 261m give this hill 21.6m of drop.



Cefn Creigiau    c 275m    SN 766 735

A contentious entry in to the Sub-List as this hill’s qualification is dependent upon an estimated summit height.  The uppermost contour is c 270m and its height has been estimated as c 275m based on the positioning of its descending contours.  The area of the bwlch has a 255m spot height at SN 768 736 on the Ordnance Survey enlarged Geograph map, this spot height is not centred but has been accepted, giving this hill c 20m of drop.



Pt. 272m    272m    SN 517 334

This hill’s name follows the Pt. notation as the blog author does not know an appropriate name for it.  Although it is tempting to use the name of Cae’r Blaidd which appears near to this hill’s summit.  However, this is probably the name given to the buildings just to the south-east of the summit and not to the hill itself.  The Ordnance Survey enlarged Geograph map has a summit spot height of 272m, and bwlch contouring is between c 250c – c 255m, with the bwlch height estimated as c 252m.  The area of the bwlch has a 251m spot height appearing at SN 516 338 on the Ordnance Survey 1:50,000 and enlarged Geograph map, this is considered not to be positioned at the critical bwlch.  The values of 272m and c 252m give this hill a drop of c 20m.



Pt. 254m    254m    SN 541 337

Another hill name that follows the Pt. notation as no appropriate name is known for it by the blog author.  The bwlch contouring is between c 230m – c 235m, with the height of the bwlch estimated as c 234m, giving this hill c 20m of drop.



Pt. 246m    246m    SN 949 529

According to current maps the area of this hill’s bwlch is now a quarry, or the remains of one.  The bwlch contouring is between c 220m – c 230m and the height of the bwlch has been estimated as c 226m.  However, quarried land is notorious for giving accurate estimation of height, but c 226m is the best I can do.  The given name follows the Pt. notation as the blog author does not know an appropriate name for the hill.  The summit value of 246m and bwlch value of c 226m give this hill a drop of c 20m.



Next update due on the 8th September 2014

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