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 twelfth
Group is Bryniau Dyfi.
Bryniau
Dyfi
North and then west of the
Afon Dyfi (River Dovey) from SH 753 018 to SH 861 149, continuing south of the
Afon Cerist to Bwlch Oerddrws at SH 802 170 and the Nant Tyn-twll to SH 767
167, continuing east of the Afon Clywedog to bwlch at SH 756 139 and the Nant
yr Allt-oen and the Afon Fawnog and Afon Faw to Llyn Mwyngil (Tal y Llyn Lake)
at SH 720 103, continuing east from stream at SH 724 102 to bwlch at SH 737 093
and following stream to SH 757 077 and the Afon Dulas to SH 753 018. Bordering with the Aran to the north, Cadair
Idris and Tarennydd to the west, Pumlumon to the south and Mynydd y Cemaes and Y
Berwyn to the east.
Twmpau - 200m updates
Mynydd
Llwyn-gwern 276m SH 766 045
This hill is promoted from the Sub-List as Harvey
Maps have a 276m summit spot height, no spot height can be found on any
Ordnance Survey map for the summit. The
bwlch has a 242m spot height on the Ordnance Survey enlarged Geograph map,
giving this hill 34m of drop.
Sub-Twmpau - 100m updates
Cefn Llandybo 259m
SH 835 098
This hill has a 259m summit and 235m bwlch spot
height on the Ordnance Survey 1:25,000 Explorer map as well as the enlarged
Geograph map, giving this hill 24m of drop.
Pt. 247m 247m
SH 829 074
The Ordnance Survey enlarged Geograph map give this
hill a summit spot height of 247m and a bwlch spot height of 226m, giving this
hill 21m of drop.
Pt. 259m 259m
SH 789 047
This hill follows the Pt. notation as the blog
author does not know an appropriate name for it. It has a 259m summit spot height on the
Ordnance Survey 1:25,000 Explorer map as well as the enlarged Geograph map,
whilst the latter map gives a spot height on the area of the bwlch of 239m,
giving this hill 20m of drop.
Next update due on the 7th July 2014
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