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 ninth Group
is Y Berwyn.
Y
Berwyn
North from the Afon Efyrnwy
(River Vyrnwy) and the border with England at SJ 268 205 to SJ 143 114,
continuing north of the Afon Banwy to Bwlch y Fedwen at SH 934 138, continuing
north of the Afon Dugoed and Afon Cleifion to SH 857 125, continuing east of
the Afon Dyfi (River Dovey) to SH 889 219 and then to Bwlch Sirddyn at SH 884
229 and the Afon Groes to SH 894 269, continuing east of the Afon Twrch to SH
881 312 and the Afon Dyfrdwy (River Dee) to Llyn Tegid (Bala Lake) at SH 890
315, continuing south following the Afon Dyfrdwy (River Dee) from SH 929 351 to
SH 317 395 and the border with England.
Bordering with Carnedd Wen and Mynydd y Cemaes to the south, Bryniau
Dyfi, Aran and Arennig to the west, Bryniau Clwyd to the north and the English
border to the east.
Twmpau - 200m updates
Y Foel 258m
SH 993 117
A promotion from the sub-list as the summit spot
height on Ordnance Survey maps is 258m and the height of the bwlch is estimated
as c 227m (bwlch contouring between c 220m – c 230m), giving a drop of c
31m. The hill was originally listed as
Foel, the definite article ‘Y’ has now been added.
Sub-Twmpau - 200m updates
Bachrug c 292m
SJ 138 150
This hill has an estimated summit height of c 292m,
with an uppermost summit contour of c 290m.
It has a spot height of 263m on the area of its bwlch on the Ordnance
Survey enlarged Geograph map, giving a drop of c 29m. An ideal hill to survey with the Trimble for
P30 status.
Pt. 209m 209m
SJ 163 254
Another hill that uses the Pt. notation as no
suitable name has been found for it by the blog author. The summit has a 209m spot height and with
bwlch contouring between c 180m – c 190m, with an estimated bwlch height of c
27m. It means this hill qualifies for
the Sub-list with an estimated drop of c 27m.
Coed
Lletty-yr-eos 248m SJ 132 207
As the uppermost and opposing bwlch contours are
relatively close on the valley to valley traverse, the height of the bwlch has
been estimated as c 223m (bwlch contouring between c 220m – c 230m). And with a summit spot height of 248m, this
gives the hill c 25m of drop.
Pt. 238m 238m
SJ 129 193
The summit and bwlch of this hill both possess a spot
height, 238m and 216m respectively. This
gives the hill a drop of 22m. The Pt.
notation is used as no name is known for the hill by the blog author.
Pt. 213m 213m
SJ 214 218
As the blog author does not know an appropriate
name for this hill the Pt. notation is being used. The summit has a 213m spot height and the
bwlch has a 191m spot height on the Ordnance Survey enlarged Geograph map. Although the latter spot height is not
centred, its position is acceptable, giving the hill 22m of drop.
Berwyn 236m
SJ 207 224
The 236m summit height is taken from the Ordnance
Survey 1:25,000 map, and with bwlch contouring between c 210m – c 215, with an
estimated height of c 214m, it gives this hill a drop of c 22m. The name of Berwyn is positioned near to the
summit of this hill on larger scale Ordnance Survey maps. However, there is a farm placed at SJ 205
222, that this name may apply to.
Pt. 212m 212m
SJ 112 135
With a 212m summit spot height, and a 191m bwlch
spot height on the Ordnance Survey enlarged Geograph map, this hill has 21m of
drop. As no appropriate name is known
for the hill the Pt. notation has been used.
Chirk Castle c 212m
SJ 268 381
Excellent news – you can go to Chirk Castle and bag
a Sub hill! The summit of this hill is
somewhere in the confines of Chirk Castle, it could well be in the tea
room. The bwlch contouring is between c
190m – c 195m and is estimated as c 191m, giving the hill c 21m of drop. I wonder if the Trimble would pick up data in
a tea room?
Pt. 298m 298m
SJ 032 139
As no appropriate name is known for this hill by
the blog author it is another example where the Pt. notation is used. The summit has a 298m spot height and the
bwlch height is estimated as c 278m at SJ 024 140, giving a drop of c 20m.
Pt. c 291m c 291m
SJ 067 162
The summit height has been estimated as c 291m as
the hill has a small uppermost c 290m ring contour. The bwlch has a 271m spot height at SJ 063
159 on the Ordnance Survey enlarged Geograph map, giving this hill a drop of c
20m.
Green Hall Hill 256m
SJ 156 192
With a summit spot height of 256m and an estimated
bwlch height of c 236m, based on bwlch contouring of c 230m – c 240, this hill
has c 20m of drop.
Next update due on the 16th June 2014
No comments:
Post a Comment