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 tenth Group
is the Breiddin.
Breiddin
North from border with
England at SJ 309 125 following stream to Pwll Trewern and the Afon Hafren
(River Severn) at SJ 265 118, continuing east and then south of the Afon Hafren
(River Severn) to SJ 328 158 and the border with England. Bordering with Carnedd Wen to the north and
west, Cefn Digoll to the south and the English border to the east.
Sub-Twmpau - 200m updates
Brimford
Wood c 258m SJ 304 143
There is only one update to the
hills of the Breiddin and that is to Brimford Wood which is a new Sub. The uppermost contour is c 255m and the
height of the hill has been estimated as c 258m. The bwlch contouring is between c 235m – c
240m and has been estimated as c 237m, giving a drop of c 21m.
Next update due on the 23rd June 2014
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