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 sixth Group
that has major updates is the Arennig.
Arennig
North of the Afon Wnion from
SH 711 190 to bwlch at SH 850 267, continuing north and west of the Afon Dyfrdwy
(River Dee) to Llyn Tegid (Bala Lake) at SH 890 314, continuing north and west of
the Afon Dyfrdwy (River Dee) from SH 929 351 to SJ 060 425, continuing south of
the Afon Alwen to SJ 022 442 and the Afon Ceirw to SH 953 475, continuing south
of the Afon Nug to bwlch at SH 928 499, continuing south of the Afon Merddwr to
SH 856 511, and then east of the Afon Conwy to bwlch at SH 760 432, continuing east
and south of the Afon Gam and the Afon Cynfal to SH 652 397, east of the Afon
Prysor to Llyn Trawsfynydd at SH 674 377, continuing east of the Afon Eden and
Afon Mawddach to SH 711 190. Bordering
with Cadair Idris to the south, Aran and Y Berwyn to the east, Mynydd Hiraethog
to the north and the Moelwynion and Rhinogydd to the west.
Twmpau - 200m updates
Bryn Coch 293m
SH 873 325
This hill has been promoted from the sub-list as
the bwlch contouring suggests a critical bwlch height of c 263m, giving this
hill c 30m of drop.
Coed Glanllyn 249m
SH 884 321
The listed name of this hill has been altered from
Pen Coed Glanllyn to Coed Glanllyn as the ‘Pen’ part of the name was invented
and unnecessary, the name of Bryniau appears on current Ordnance Survey maps
and has been used in other P30 listings, but map study implies this name
relates to the buildings at SH 884 324 and not to the hill itself. This hill has been promoted from the sub-list
as the large scale Ordnance Survey mapping on the Geograph website gives a 249m
spot height on the area of the summit.
The bwlch contouring suggests a critical bwlch height of c 219m at SH
881 323, giving c 30m of drop.
Pt. 245m 245m
SH 997 438
This hill used to be listed in the sub-list with c
28m of drop under the name of Carreg-y-big.
The drop value was estimated from bwlch contouring between c 210m – c
220m. The Pt. notation has now been used
for its name as mapping suggests that the name Carreg-y-big applies to the
building situated at SH 998 438 and not directly to the hill itself. However, many farm buildings are named after
‘their’ hill and this may be the case here, but until further investigation the
name converts to the Pt. notation.
The large scale Ordnance Survey mapping on the
Geograph website gives a 215m spot height on the area of the bwlch. Although the valley to valley traverse is
relatively expansive the spot height appears in the approximate position where
interpolation suggests the critical bwlch is placed. Its 215m bwlch is at SH 994 434, giving 30m of
drop.
Pen
y Foel 214m SH 661 395
Another hill promoted from the sub-list as the
large scale Ordnance Survey mapping on the Geograph website gives a 214m spot
height on the area of the summit. The
only other height to have appeared for this hill is 212m on the Ordnance Survey
1:50,000 map, this matches the old imperial height of 696ft.
The bwlch contouring is between c 180m – c 190m
with the valley to valley contours closer than the hill to hill contours, implying
a bwlch height of c 184m. It is hoped to
accurately survey this hill in the future for P30 confirmation, but for now it
enters the Welsh 200m P30 list.
This hill is listed with a summit height of 214m
and a bwlch height of c 184m, giving c 30m of drop.
Sub-Twmpau - 200m updates
Pt.
205m 205m SH 730 254
The 205m height for this hill
comes from Harvey Maps and the bwlch height is estimated as c 177m at SH 730
260, giving this hill c 28m of drop.
Pt.
285m 285m SH 993 377
This
hill was originally in the P30 list under the name of Bryn Cae-pant, which was
an invented name partly taken from buildings to the west. The Pt. notation has now been used for its
name as using an invented name is inappropriate. There is a 258m spot height at SH 993 381 on
the area of the bwlch on the large scale Ordnance Survey mapping on
the Geograph website, giving this hill 27m of drop.
Pt.
278m 278m SJ 001 378
The area of the bwlch has a
254m spot height at SH 997 379 on the large scale Ordnance Survey mapping on
the Geograph website, this gives the hill 24m of drop.
Pt.
c 271m c 271m SH 985 376
The summit height has been
estimated as c 271m and the large scale Ordnance Survey mapping on the Geograph
website has a 247m spot height on the area of the bwlch at SH 990 377, giving
the hill c 24m of drop.
Pt.
c 264m c 264m SH 896 334
The height of this hill has
been estimated as c 264m, and with a 241m spot height at SH 898 337 on the area
of the bwlch on the large scale Ordnance Survey mapping on the Geograph
website, it gives this hill c 23m of drop.
Pt.
234m 234m SH 870 510
The large scale Ordnance Survey
mapping on the Geograph website has a 212m spot height on the approximate
position where contour interpolation places the critical bwlch at SH 871 508,
giving this hill 22m of drop.
Pt.
258m 258m SH 711 360
This hill is positioned just
outside of Trawsfynydd and has a summit spot height of 258m on the large scale
Ordnance Survey mapping on the Geograph website. The height of its bwlch is estimated as c
237m at SH 712 360, giving c 21m of drop.
Pt.
207m 207m SH 791 213
The bwlch height is estimated
to be c 186m at SH 792 214, giving this hill c 21m of drop.
Pt.
296m 296m SH 723 284
The summit and bwlch of this
hill looks as if they are immersed in conifer plantation. The bwlch height is estimated to be c 276m at
SH 721 288, giving this hill c 20m of drop.
Coed
y Groes Pt. c 242m SH 744 209
This hill’s summit and bwlch
height have been estimated from contour interpolation. The area of the bwlch has two spot heights on
it, both on the minor road that passes the old Nannau estate. These are 221m at SH 745 208 and 223m at SH
745 209, both are shown on the large scale Ordnance Survey mapping on the
Geograph website. I’ve investigated this
area on Google Maps, and although not conclusive I’ve opted for a bwlch height
of c 222m at SH 74528 20926, giving this hill c 20m of drop.
Next update due on the 26th May 2014
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