Mapping Mountains – Hill Reclassifications – The Fours - The 400m Hills of England

Pt. 423.9m (SX 753 768) – 400m Sub-Four addition

There has been an addition 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 derived from LIDAR analysis initially conducted by Aled Williams and subsequently by Myrddyn Phillips.

LIDAR image of Pt. 423.9m (SX 753 768)

The criteria for the list that this addition 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 list are three categories of sub hills, with this hill being added to the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m 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 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The hill is being listed by the Point (Pt. 423.9m) notation and it is adjoined to the Broad Barrow group of hills, which are situated in Dartmoor in the south-west of England, and it is positioned with minor roads to its north, north-west and north-east, and the B3387 road to its south, and has the small community of Haytor Vale towards the east north-east.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was not included in the 400m Sub-Four category and was listed with an estimated c 18m of drop, based on the 422m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and an estimated c 404m col height, based on interpolation of 10m contouring between 400m - 410m.

Extract from the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map

However, it was not until LIDAR became available that the details for this hill 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.

Therefore, the addition of this hill to 400m Sub-Four status is due to LIDAR analysis, resulting in a 423.9m summit height and a 403.2m col height, with these values giving this hill 20.7m of drop, which is sufficient for 400m Sub-Four status. 

The full details for the hill are:

Group:  Broad Barrow

Name:  Pt. 423.9m

OS 1:50,000 map:  191

Summit Height:  423.9m (LIDAR)

Summit Grid Reference:  SX 75331 76844 (LIDAR)

Col Height:  403.2m (LIDAR)

Col Grid Reference:  SX 75476 76932 (LIDAR)

Drop:  20.7m (LIDAR)

For the additions, deletions and reclassifications to The Fours - The 400m Hills of England reported on Mapping Mountains since the December 2013 publication of the 1^st edition of this list by Europeaklist please consult the following Change Registers:

The Fours

The Fours – 400m Sub-Four

The Fours – 390m Sub-Four

The Fours – 390m Double Sub-Four

Myrddyn Phillips and Aled Williams (June 2018)