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 fifteenth
Group is Pumlumon.
Pumlumon
North of Aberystwyth at
SN 579 808 and the Afon Rheidol to SN 749 807, continuing north of the Afon Castell
to Eisteddfa Gurig at SN 797 841 and the Afon Tarrenig to SN 841 826 and the
Afon Gwy (River Wye) to SN 910 792, continuing north of stream to bwlch at SN
927 800, continuing west of the Nant Gynwydd to SN 952 820 and the Afon Dulas
to SN 945 838 and the Afon Hafren (River Severn) to SO 027 916, continuing
south of the Afon Carno to bwlch at SN 930 998 and the Afon Laen to SH 890 027
and the Afon Twymyn to SH 821 052, and then the Afon Dyfi (River Dovey) to Bae
Aberdyfi (Aberdovey Bay) and the sea at SN 592 945. Bordering with the Tarennydd, Bryniau Dyfi,
Mynydd y Cemaes and Carnedd Wen to the north, Pegwn Mawr and Garreg Lwyd to the
east, Elenydd to the south and the sea to the west.
Twmpau - 200m updates
Pt.
252m 252m SN 797 954
A hill whose name has reverted
to the Pt. notation as it was previously listed in the Sub list as Mynydd
Rhiw-gam, which was partly invented from a wood to the west of the summit. The bwlch contouring is between c 220m – c
230m, with the valley to valley contours being close together, implying a bwlch
height of c 221m, giving this hill c 31m of drop.
Pt.
237m 237m SN 809 977
This hill was originally
listed as Penyglôg, map study indicates that this name applies to the farm to
the north-east of the summit. The name
of Cae’r Allt appears on the south-westerly slopes of this hill on Ordnance
Survey maps, but as this name may apply to an enclosed field and not the hill
or its summit, the name of the hill is reverting to the Pt notation. The 237m summit height is taken from the
Ordnance Survey enlarged Geograph map and the height of the bwlch has been
estimated as c 203m from bwlch contouring between c 200m – c 210m, giving this
hill c 34m of drop.
Mynydd
Cae-du 227m SN 728 985
A hill whose promotion
from the Sub list is reliant upon details from the Ordnance Survey enlarged
Geograph map, as both summit and bwlch are spot heighted with 227m and 194m
respectively, giving this hill 33m of drop.
Sub-Twmpau - 200m updates
Cefn Modfedd 289m
SN 788 972
This hill qualifies for the Sub list with an
estimated c 26m of drop, based on a 289m summit height and an estimated c 263m
bwlch height. The area of the bwlch has
a 264m spot height at SN 787 970 on the Ordnance Survey enlarged Geograph map
positioned on a track, this has been judged too high and not at the critical
bwlch. However, saying that, the c 260m
– c 270m contouring position suggests that this latter spot height is quite
close to where the critical bwlch is positioned.
Pen yr Allt 267m
SH 842 025
Pen yr Allt has bwlch contouring between c 240m – c
250m, with the height of the bwlch estimated as c 242m, giving this hill c 25m
of drop.
Pt. 246m 246m
SN 814 981
This hill follows the Pt. notation as the blog
author does not know an appropriate name for it. As the valley to valley contours are close
together the bwlch height has been estimated as c 221m, based on bwlch contouring
between c 220m – c 230m, giving this hill c 25m of drop.
Foel Fach 297m
SN 815 963
This hill is situated on the north-westerly
descending ridge of Foel Fadian. It has
bwlch contouring between c 270m – c 280m with an estimated bwlch height of c
274m, giving this hill c 23m of drop.
Banc
Troedrhiwseiri 233m SN 671 854
A hill that has two uppermost c 230m ring contours,
with the westerly one being 1m higher according to the map (the Ordnance Survey
enlarged Geograph map gives the easterly ring contour a 232m spot height). The OS enlarged Geograph map also spot
heights the bwlch as 211m, this appears at a cross roads, the same position
where a 212m spot height appears on the OS 1:50,000 map. These values give this hill 22m of drop.
Castell
Bwa-drain 298m SN 712 794
Castell Bwa-drain is an ancient hill fort with
commanding views over the Afon Rheidol, it qualifies for the Welsh 200 Sub-P30
list as it is given a height of 298m on Ordnance Survey maps and has bwlch
contouring between c 270m – c 280m, with an estimated bwlch height of c 276m,
giving this hill c 22m of drop.
Pt. 216m 216m
SN 729 978
A contentious entry in to the Sub list as it is
based on the 216m summit spot height that appears on the Ordnance Survey
enlarged Geograph map. This spot height
could be a typo as no c 210m ring contour exists; therefore the height may in
fact be 206m. However, for now the hill
enters the Sub list. It also has a twin
216m top at SN 731 981 that also suffers from a lack of a c 210m ring contour. The bwlch contouring is between c 190m – c
200m and is estimated as c 194m at SN 731 982, with an alternate 194m bwlch
height being positioned at SN 729 980.
If the 216m summit height is correct this hill has c 22m of drop.
Pt. 208m 208m
SN 985 896
Another hill that follows the Pt. notation as the
blog author does not know an appropriate name for it. The bwlch contouring is between c 180m – c
190m with an estimated height of c 186m, giving this hill c 22m of drop.
Pt. 273m 273m
SN 695 878
Although the name of Ffridd Cwmere appears near to
the summit of this hill on some Ordnance Survey maps, the Pt. notation is being
used for the name of the hill as the ffridd name may only apply to the bounded
land to the west of the land where the summit of this hill is situated. With a summit height of 273m and a bwlch
height of 252m, the latter coming from the Ordnance Survey enlarged Geograph
map, this hill has 21m of drop.
Pt. 276m 276m
SN 717 788
The bwlch contouring for this hill is between c
250m - c 260m and is estimated as c 255m at SN 719 790, giving this hill a drop
of c 21m.
Ffridd
Rhosygarreg 297m SN 806 947
With a summit height of 297m and an estimated bwlch
height of c 277m, based on bwlch contouring between c 270m – c 280m, this hill
has c 20m of drop.
Mynydd Eithaf c 278m
SN 750 974
Another contentious entry as both summit and bwlch
height have been estimated, and even after this the drop figure only comes to c
20m. The bwlch contouring is between c
250m – c 260m and has been estimated as c 258m, whilst the summit height is
estimated as c 278m based on the area of the uppermost contour ring compared to
how close the ascending contour rings are to one another.
Cae’r Orseddan 223m
SN 805 998
This hill has bwlch contouring between c 200m – c
210m with the height of the critical bwlch estimated as c 203m, this gives the
hill c 20m of drop.
Cefn Maesmawr
Bach 217m SN 727 981
Another hill that qualifies for the Sub list with c
20m of drop, based on a summit height of 217m and a bwlch height of c 197m,
with bwlch contouring between c 190m – c 200m.
Next update due on the 28th July 2014
No comments:
Post a Comment