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 Twenty
Third Group is Mynydd Bach.
Mynydd
Bach
Initially east, then
north and finally west of the Afon Teifi from SN 158 492 to Cors Caron at SN
677 622, continuing west of the Camddwr to bwlch at SN 645 687 and west and
then south of the Afon Wyre to SN 527 699.
Bordering with the Elenydd to the north, east and south, and Moelfre and
Mynydd Preseli to the south and the sea to the west.
Twmpau - 200m updates
Blaen
Wern Wood c 226m SN 564 484
This hill is a summit
relocation and a promotion from the Sub-List, as its previously listed 224m
summit was positioned at SN 550 487 and appeared in the Sub-List under the part
invented name of Allt Ty-llwyd. The advent
of the Ordnance Survey enlarged Geograph map now gives us 5m contour intervals
for this area and with an uppermost c 225m contour Blaen Wern Wood replaces the
hill at SN 550 487. The summit height
has been estimated as c 226m and the bwlch as c 194m, the latter based on bwlch
contouring between c 190m – c 195m.
These values give this hill c 32m of drop.
Sub-Twmpau - 200m updates
Moel
Rhydeinon 290m SN 427 542
The height of this hill appears
as 289m on Ordnance Survey maps, this height is given to a trig pillar. The OS Trig Database gives a height of
290.254m adjoined to the flush bracket on the trig, as flush brackets are
usually positioned 0.30m – 0.35m above the ground, the base of the trig would
be at 289.904m – 289.954m, therefore this height has been rounded up to 290m
for the purposes of this list. The notes
in the OS Trig Database state ‘station moved by farmer, B/Bolt poss. OK’. If the height quoted is not to a flush
bracket it may be to a bolt. The bwlch
is positioned at SN 407 527 with contouring between c 260m – c 265m, and has
been estimated as being c 262m high.
These values give this hill c 28m of drop.
Pt. 234m 234m
SN 498 481
Another hill name that follows the Pt notation as
no appropriate name is known for it by the blog author. This hill has a 208m spot height on the area
of its bwlch that appears on the Ordnance Survey enlarged Geograph map, giving
this hill 26m of drop.
Pt. 271m 271m
SN 375 467
This hill qualifies for the Sub-List as it has a
246m spot height on the area of its bwlch that appears on the Ordnance Survey
enlarged Geograph map. Its name follows
the Pt. notation as the blog author does not know an appropriate name for it,
and it is one of many that do so in the Welsh 200m Sub-P30 List. The summit value of 271m and bwlch value of
246m gives this hill 25m of drop.
Pt. 292m 292m
SN 404 519
The summit of this hill has a 292m spot height on
it and its name takes on the customary Pt. notation as no appropriate name is
known for it by the blog author. The
bwlch contouring is between c 265m – c 270m and has been estimated as c 267m
high. There are two spot heights that
appear in the area of the bwlch on Ordnance Survey maps, the first is placed at
a road junction at SN 396 518, this 268m spot height is considered to be placed
too high for the critical bwlch position.
The second spot height is 266m and is placed at a road junction and
appears on the Ordnance Survey enlarged Geograph map at SN 397 520, although
near to where interpolation suggests the critical bwlch to be placed it is
considered slightly too low. The 292m
summit and c 267m bwlch values give this hill c 25m of drop.
Pt. 289m 289m
SN 417 535
The 289m summit spot height appears near to where a
Covered Reservoir is placed on the Ordnance Survey map. If this height was to the top of the covered
reservoir the height would likely have to decrease for this list, as covered
reservoirs are considered modern mad-made objects and do not count for the
height of a hill under the parameters of this list. The name of this hill is another that follows
the Pt. notation as no suitable name is known for it by the blog author. Bwlch contouring is between c 260m – c 265m
and the height is estimated as c 264m at SN 424 536. The Ordnance Survey enlarged Geograph map has
a 262m spot height near to a centralised bwlch location at SN 425 535, but this
is considered too low for the critical bwlch position. The 289m summit and c 264m bwlch values give
this hill c 25m of drop.
Pt. 237m 237m
SN 574 557
The name of this hill follows the Pt. notation
which is considered appropriate as no suitable name is known for the hill by
the blog author. The bwlch contouring is
between c 210m – c 215m and the height of the bwlch is estimated as c 212m,
giving this hill c 25m of drop. There is
a 211m spot height at SN 570 557 on Ordnance Survey maps, as the placement of
this spot height is down steam of a Spring it is considered not to be at the
point of the critical bwlch.
Allt
Gelligarneddau 256m SN 606 556
This hill qualifies for the Sub-List as it has an
estimated bwlch height of c 232m, based on bwlch contouring between c 230m – c
240m, giving this hill c 24m of drop.
The next nearest higher summit is to the south of this hill at SN 611
542 and is reliant on being higher due to a 257m spot height appearing on the
Ordnance Survey 1:50,000 map.
Allt Cwm-hyar 266m
SN 383 451 / SN 381 455
A Twin Top as there are two points with a 266m
summit spot height, between the two summits is a 264m spot height that appears
on the Ordnance Survey enlarged Geograph map at SN 381 454. The bwlch has a 243m spot height on it at SN
379 463, giving this hill 23m of drop.
Banc y Carnau 239m
SN 523 594
This hill qualifies for the Sub-List as it has a
239m summit spot height and a 216m bwlch spot height, giving this hill 23m of
drop. The bwlch spot height is
positioned at SN 524 592 and appears on the Ordnance Survey enlarged Geograph
map.
Castell Goetre 235m
SN 602 509
Another hill whose qualification in the Sub-List is
partly dependent upon the Ordnance Survey enlarged Geograph map, as this map
gives a 212m spot height on the area of the bwlch, giving this hill 23m of
drop.
Pt. 259m 259m
SN 662 650
Another hill whose listed name follows the Pt.
notation as the blog author does not know an appropriate name for it. The height of the bwlch has been estimated as
c 236m, based on bwlch contouring between c 230m – c 240m, giving this hill c
23m of drop.
Pt. 248m 248m
SN 644 633
This hill’s qualification in to the Sub-List is
reliant upon the Ordnance Survey enlarged Geograph map as it shows a summit
spot height of 248m, whereas other current maps only have an uppermost c 240m
contour ring. The bwlch contouring is
between c 220m – c 230m and the height of the bwlch has been estimated as c
225m, giving this hill c 23m of drop.
Pt. 268m 268m
SN 431 483
The listed name of this hill follows the Pt.
notation as no suitable name is known for it by the blog author. The area of the bwlch has a 246m spot height
at SN 436 494 appearing on the Ordnance Survey enlarged Geograph map, giving
this hill 22m of drop.
Pt. c 256m c 256m
SN 555 542
Another hill whose name follows the Pt. notation as
the blog author does not know an appropriate name for it. Both summit and bwlch heights have been
estimated, the former from an uppermost c 255m contour ring and the latter from
contouring between c 230m – c 235m, with an estimated bwlch height of c 234m,
giving this hill a drop of c 22m.
Pt. 224m 224m
SN 580 526
This hill qualifies for the Sub-List as it has a
summit spot height of 224m and a bwlch spot height of 203m, giving this hill a
drop of 21m. The bwlch spot height
appears on the Ordnance Survey enlarged Geograoh map at SN 570 546. This hill is also another example where the
Pt. notation is being used for the listed name as the blog author does not know
an appropriate name for it.
Crug y Balog 244m
SN 342 452
The summit spot height for this hill appears on the
Ordnance Survey 1:25,000 map, the bwlch contouring is between c 220m – c 225m
and has been estimated as c 223m high, giving this hill a drop of c 21m. The Ordnance Survey 1:50,000 map also has a
223m spot height at SN 345 457 on the area of the bwlch. However, this may be misplaced as its
position appears higher than the c 225m contour when the map is enlarged on the
Geograph mapping available on its website.
Allt Hoffnant 239m
SN 326 523
This hill qualifies for the Sub-List as it has a
239m summit spot height and a 219m bwlch spot height positioned at SN 332 516,
giving the hill 20m of drop. This hill
also has a Twin Top at SN 326 509 which is regarded as the prioritised summit
and which qualifies for the main list of P30 hills with 45m of drop, with its
194m bwlch positioned at SN 339 522.
Pt. 224m 224m
SN 524 514
This hill name follows the Pt. notation as the blog
author does not know a suitable name for it.
The hill qualifies for the Sub-List as it has a 224m summit spot height
and a 204m bwlch spot height, giving the hill 20m of drop.
Pt. 295m 295m
SN 561 600
This is another example where the hill name follows
the Pt. notation as no appropriate name is known for it by the blog
author. The contouring for this area is
at 5m intervals on the Ordnance Survey enlarged Geograph map, the position of
the bwlch is placed at SN 558 602 where two minor roads meet. Unfortunately the c 275m contour on the
Geograph map goes in to each road but does not continue out of them; therefore
it is difficult to tell if the bwlch contouring is between c 270m – c 275m or
between c 275m – c 280m. For the
purposes of this list I’m estimating the height of the bwlch as c 275m, giving
this hill a drop of c 20m.
Next update due on the 22nd September 2014
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