Lord’s Seat (NT 912 079) – 390m Sub-Four reclassified to 390m
Double Sub-Four
There has been a reclassification to the listing
of the The Fours – The 400m Hills of England,
with the summit height, col height and their locations, the drop and status
of the hill confirmed by LIDAR analysis.
This was initiated by Joe Nuttall who produced a summit analysis programme that used LIDAR with an alternative height map (DEM) allowing identification of summits and cols and thereby drops. The resulting spreadsheet that Joe produced
contains over 29600 hills.
This spreadsheet is being evaluated by DoBIH Editors
and others, and for this particular hill it was Jim Bloomer who initially
assessed its height and that of its adjacent peak via LIDAR analysis.
Myrddyn Phillips then evaluated this hill’s
details via LIDAR analysis and confirmed its drop value and hence its
reclassification.
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| LIDAR image of Lord's Seat (NT 912 079) |
The criteria for the list that this reclassification
applies to are:
The Fours – The 400m Hills of England. English
hills at or above 400m and below 500m in height that have 30m minimum drop,
accompanying the main listing of The Fours are three categories of sub hills,
with this hill being reclassified from the 390m Sub-Four category to the 390m
Double Sub-Four category. The criteria
for 390m Sub-Four status being all English hills at or above 390m and below 400m
in height that have 30m minimum drop and the criteria for 390m Double Sub-Four
status being all English hills at or above 390m and below 400m in height that
have 20m or more and below 30m of drop.
The list is co-authored by Myrddyn Phillips and Aled Williams and the 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.
 |
| The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams |
The name the hill is listed by is Lord’s Seat, and it is adjoined to The Cheviot
group of hills, which are
situated in the north-eastern part of England (Region 33 Scottish Border to the
River Tyne), and it is positioned with a minor road to its south-east and
farther afield has the A68 road to its south-west, the B6341 road to its
south-east and the A697 road to its east, and has the town of Rothbury towards
the east south-east.
When the 2nd edition of the The Fours – The 400m Hills of England was
published by Mapping Mountains Publications in April 2018, this hill was listed
as a 390m Sub-Four with an estimated c 53m of drop, based on the 392m summit spot
height and an estimated c 339m col height based on interpolation of 10m
contouring between 330m – 340m that appear on the Ordnance Survey 1:50,000
Landranger and 1:25,000 Explorer map.
 |
| Extract from the Ordnance Survey 1:25,000 Explorer map |
Approximately 1km to the south-west of the summit
of Lord’s Seat is the triangulation pillar on the hill named Green Side. The flush bracket adjoined to this trig
pillar is given as 389.534m and positioned at NT 90299 07313 in the OS Trig
Database, with its map height given as 389m.
As the map height of Green Side is lower than Lord’s Seat the former was
unclassified with an estimated c 17m of drop and Lord’s Seat listed as the 390m
Sub-Four.
However, it was not until LIDAR became available
that the details for these two hills could be accurately re-assessed. The LIDAR (Light Detection & Ranging)
technique produced highly accurate height data that is now freely available for
much of England and Wales.
LIDAR results for each summit:
Lord’s Seat:
392.2m at NT 91281 07968 and NT 91282 07966
Green Side:
395.5m at NT 90695 07602
As Green Side is higher than Lord’s Seat the respective cols
are swapped and Green Side becomes the 390m Sub-Four. However, the subsequent drop for Lord’s Seat
is sufficient for it to be classified as a 390m Double Sub-Four.
 |
| LIDAR image of Lord's Seat and Green Side |
Therefore, the reclassification of Lord’s Seat from
390m Sub-Four status is due to LIDAR analysis, resulting in a 392.2m summit
height and a 370.9m col height, with these values giving this hill 21.3m of
drop, which is insufficient for 390m Double Sub-Four status.
The full details for the hill are:
Group: The Cheviot
Name: Lord’s Seat
OS 1:50,000 map: 80
Summit Height: 392.2m (LIDAR)
Summit Grid Reference:
NT 91281 07968 and NT 91282 07966 (LIDAR)
Col Height: 370.9m (LIDAR)
Col Grid Reference: NT
90985 07852 (LIDAR)
Drop: 21.3m (LIDAR)
For the additions, deletions and reclassifications to The Fours reported on Mapping Mountains
since the December 2013 publication of the list by Europeaklist please consult
the following Change Registers:
Our thanks to Joe Nuttall and Jim Bloomer for bringing the
details of this hill to our attention.
Myrddyn Phillips and Aled Williams (July 2020)
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