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

Merripit Hill (SX 657 803) – 400m Sub-Four deletion

There has been a deletion 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 Merripit Hill (SX 657 803)

The criteria for the list that this deletion 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 deleted from 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 name the hill is listed by is Merripit Hill and it is adjoined to the High Willhays group of hills, which are situated in Dartmoor in the south-west of England, and it is positioned with the B3212 road to its south-east, and has the small community of Postbridge to the south-west.

When the list that is now known as The Fours – The 400m Hills of England was originally compiled this hill was not included in the accompanying sub list, as it was considered not to meet the criteria used for this sub category.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed as a 400m Sub-Four with 20m of drop, based on the 449m summit spot height and the 429m col spot height that appear on the contemporary Ordnance Survey 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer 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 deletion of this hill from 400m Sub-Four status is due to LIDAR analysis, resulting in a 449.7m summit height and a 430.0m col height, with these values giving this hill 19.7m of drop, which is insufficient for it to retain its 400m Sub-Four status. 

  

The full details for the hill are:

Group:  High Willhays

Name:  Merripit Hill

OS 1:50,000 map:  191

Summit Height:  449.7m (LIDAR)

Summit Grid Reference:  SX 65782 80369 (LIDAR)

Col Height:  430.0m (LIDAR)

Col Grid Reference:  SX 65888 80811 (LIDAR)

Drop:  19.7m (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)