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 seventh
Group is Mynydd Hiraethog.
Mynydd
Hiraethog
South from Bae Penrhyn
(Penrhyn Bay) at SH 829 815 to bwlch at SH 821 785 and continuing to the Afon
Conwy at SH 802 766, and then east of the Afon Conwy to SH 856 511, and then
north of the Afon Merddwr to bwlch at SH 928 499 and continuing north of the
Afon Nug to SH 953 475, the Afon Ceirw to SJ 022 442 and the Afon Alwen to SJ 060425,
continuing a short distance west of the Afon Dyfrdwy (River Dee) to SJ 066 429
and then south and west of the Afon Camddwr to the Fish Pond at Y Rug (SJ 056
438), continuing west of the Afon Camddwr to bwlch at SJ 069 477 and the Afon
Clwyd at SJ 071 500 to the sea at SJ 997 808.
Bordering with the sea and Gogarth to the north, the Carneddau to the
west, Arennig to the south and Bryniau Clwyd to the east.
Twmpau - 200m updates
Ffridd y
Mynydd 258m SH 825 758
A promotion from the sub-list and
summit relocation as this hill was originally listed as c 250m at SH 826 753
(SH 825 753). There are eleven separate
contour rings at c 250m in the vicinity of the high point of this hill, but
only one has an uppermost c 255m ring contour on the Ordnance Survey enlarged
mapping on the Geograph website. The
same ring contour has an old imperial height of 847ft (258.2m) on the Ordnance
Survey Historical 1:25,000 map. The
bwlch contouring is between c 220m – c 225m and the critical bwlch is estimated
as c 223m, giving this hill c 35m of drop.
Gallt y Celyn 258m
SH 811 542
Since drop values were added to the
list this hill has been listed with c 30m of prominence. It appeared under an invented name of Bryn
Graeanllyn but has now been amended to Gallt y Celyn which comes from the Tithe map. It has a twin summit at SH 810 544, it is
hoped that a Trimble survey can soon separate these summits. The survey took place and de-twinned the two
summits and a later bwlch survey confirmed this hill as a P30.
Dinas
Mawr 254m SH 808 539
This hill is adjacent to the twin
summits at SH 811 542 and SH 810 544 and will soon be surveyed with the Trimble
GeoXH 6000 to confirm (or otherwise) its inclusion in the Welsh 200m P30
list. Until then it is promoted from the
sub-list as bwlch contouring on current maps is between c 220m – c 230m and
suggests a height of c 224m, giving this hill a drop of c 30m. The Ordnance Survey enlarged mapping on the Geograph
website has a 221m spot height on the area of the bwlch at SH 809 539 but as it
is not centred on the hill to hill traverse it has not been used for drop
evaluation.
Pt. 253m 253m
SH 940 639
Another promotion from the sub-list as
the Ordnance Survey enlarged mapping on the Geograph website has a 253m spot
height on the area of the summit and as bwlch contouring is between c 220m – c
225m and estimated as c 223m, it gives this hill c 30m of drop. The hill was listed as Bryn Gwern-llifion
which was an invented name; it has now converted to the Pt. notation.
Pt. 211m 211m
SJ 060 618
This hill used to be listed in the
sub-list with c 29m of drop under the name of Bryn Llewesog. The summit contouring has been re-evaluated
giving this hill c 30m of drop. The Pt.
notation has now been used for its name as the previously listed name was an
invented one. The name of Pen-y-cae
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 SJ 065
622 and not to the hill itself. The name
of Coed y Plas appears on the Ordnance Survey enlarged mapping on the Geograph
website for the wood on this hill’s southern flank, this may be the locally
known name of the hill, but as the wood does not reach the summit, the name has
not been used until further investigation can take place.
Sub-Twmpau - 200m updates
Mynydd
y Gyrt 298m SH 967 693
The area of the bwlch has a
274m spot height at SH 969 690 on the large scale Ordnance Survey mapping on
the Geograph website, this gives the hill 24m of drop.
Pt.
c 216m c 216m SJ 009 646
The critical bwlch may well be
situated in someone’s living room in the small community of Groes Fawr! The summit is estimated as c 216m from an
uppermost c 215m ring contour on the Ordnance Survey enlarged mapping on the
Geograph website. The bwlch contouring
is between c 190m – c 195m and is estimated as c 192m, giving this hill c 24m
of drop.
Coed
y Fron 274m SJ 051 446
The valley to valley contours
are placed so close to one another the bwlch height is estimated to be c 251m,
with the bwlch contouring between c 250m – c 260m. With a spot height on the area of the summit
of 274m it gives this hill c 23m of drop.
The name of Coed y Fron has been used as larger scale maps indicate that
the wood just takes in the summit.
Pt.
265m 265m SH 999 646
The summit height for this hill
comes from the old imperial height of 868ft (264.6m) on the Ordnance Survey
Historical 1:25,000 and the New Popular One-Inch maps. The 868ft height also appears on a number of
1:10,560 maps. The area of the bwlch has
a 243m spot height at SH 996 647 on the large scale Ordnance Survey mapping on
the Geograph website, giving this hill 22m of drop.
Pt.
213m 213m SH 817 637
The bwlch contouring is between
c 190m – c 195m with the critical bwlch estimated to be c 192m, giving this
hill c 21m of drop.
Pt.
227m 227m SJ 019 447
The area of the bwlch has a
207m spot height at SJ 020 448 on the large scale Ordnance Survey mapping on
the Geograph website, this gives the hill 20m of drop.
Pt.
203m 203m SH 821 740
The bwlch contouring has 5m
intervals on the Ordnance Survey enlarged mapping on the Geograph website. The contours are between c 180m – c 185m,
with the critical bwlch estimated as c 183m, giving this hill c 20m of drop.
Next update due on the 2nd June 2014
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