Thursday, 27 October 2022

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

 

Pt. 476.0m (NY 399 044) – 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 prompted by Joe Nuttall who produced a summit analysis programme using LIDAR, and then confirmed by LIDAR analysis conducted by Myrddyn Phillips, with the col having been surveyed with a Leica GS15 by John Barnard, Jim Bloomer and Graham Jackson. 

LIDAR image of Pt. 476.0m (NY 399 044)

The criteria for the list that this addition applies to are:

The FoursThe 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 included in 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 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 hill is being listed by the point (Pt. 476.0m) notation as an appropriate name for it either through local enquiry and/or historic research has not been found by the authors, and it is adjoined to the High Street group of hills, which are situated in The Lake District (Region 34, Section 34C: The Eastern Fells), and it is positioned with a minor road to its north-west, the A591 road to its west and the A592 road to its east, and has the town of Ambleside towards the west.

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 not included in the accompanying sub list, as it was considered not to meet the criteria used for this sub category.

However, during the updating of this list for the 2nd edition this hill was noted and listed with an estimated c 17m of drop, based on the 474m 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 457m col height, based on interpolation of 10m contouring between 450m – 460m. 

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 addition of this hill to 400m Sub-Four status is due to LIDAR analysis and the height and position of the col confirmed by a Leica GS15 survey,  resulting in a 476.0m summit height and a 454.8m col height, with these values giving this hill 21.2m of drop, which is sufficient for it to be classified as a 400m Sub-Four.

 

The full details for the hill are:

Group:  High Street

Name:  Pt. 476.0m

OS 1:50,000 map:  90

Summit Height:  476.0m (LIDAR)

Summit Grid Reference:  NY 39930 04485 (LIDAR)

Col Height:  454.8m (Leica GS15)

Col Grid Reference:  NY 39696 04372 (Leica GS15)

Drop:  21.2m (LIDAR summit and Leica GS15 col)

 

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 1st 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 (October 2022)

 

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