Saturday, 4 February 2017

Change Register – The Fours – 400m Sub-Fours


Change Register

The Fours – The 400m Hills of England

400m Sub-Fours


The Fours are the English hills at or above 400m and below 500m in height that have a minimum drop of 30m.  The list’s initial compilation was completed in November 2002 and entitled The 400m Peaks of England and was first published on 19th December 2002 on the RHB Yahoo Group file database along with the equivalent Welsh and Manx hills, with the file entitled the 400m hills of England, Isle of Man and Wales, this file was uploaded by Rob Woodall who later augmented data from Clem Clements into the database.

The original publication on the RHB Yahoo Group file database was later duplicated en masse by Mark Jackson without prior consultation with, or even notification to the author, with these data forming the equivalent part of the Tumps and with this act resulting in years of undue data divergence that is ongoing.

Over subsequent years the listing now known as The Fours has been published on the Europeaklist website (15th December 2013) available as a downloadable e-booklet and print-booklet version and on the Haroldstreet website (6th January 2014) available as GPS Waypoints, Google mapping and online hill bagging tick lists.

The original compilation included a sub-list of hills entitled ‘Hills to be surveyed’ which was later re-evaluated and included in the Europeaklist and Haroldstreet publications.  This sub list comprised all hills identified from map study that were at or above 400m and below 500m in height and if surveyed for drop stood a chance of qualifying for the main P30 list.  At the time of compilation the spot heights on Ordnance Survey maps were taken at face value as the margin of uncertainty applicable to the surveying method that ascertained them was unknown at the time.  Therefore if a hill was given a drop value of 29m from its summit and col spot heights it was not included in this ‘Hills to be surveyed’ sub list as it was deemed not to warrant a survey for inclusion into the main P30 list as the map had given it 29m of drop.  This sub list has now been standardised and comprises all English hills that are at or above 400m and below 500m in height and have 20m or more and below 30m of drop, the name of this sub list is the 400m Sub-Fours.

It wasn’t until the interest shown by Mark Trengove for this list to be published by Europeaklist that the 400m Sub-Fours were fully re-evaluated, with the subsequent publication on 15th December 2013 entitled The Fours and leading the way to the list becoming co-authored with Aled Williams.  After the 6th January 2014 publication of The Fours by Phil Newby on his Haroldstreet website all future updates to the list have been catalogued on the Mapping Mountains site.

Since its original publication The Fours has changed greatly as the list is now co-authored with Aled Williams, and although the criteria has remained the same for the main P30 list, the criteria for the 400m Sub-Fours has now been standardised, and the numerical data benefits from the advent of accurate surveys conducted with GPS / GNSS receiver, an expanded range of Ordnance Survey maps available online and most recently, by analysis of LIDAR data enabling greater accuracy for numerical data.  However, it is not just numerical data that has seen this list develop since its first inception, it is also place-name data, and it was because of this and their mutual interest in hill lists that the authors first corresponded.  The listing is also gaining in popularity as there are now two known completers of The Fours with another 38 people having completed 100 or more of these hills.

It seems fitting that the list of The Fours – The 400m Hills of England – 400m Sub-Fours should now benefit from a detailed Change Register, and although the updates to this list have been catalogued since its first inception in 2002, it is prudent for this Change Register to initially detail the changes to this sub list since the December 2013 publication by Europeaklist.

The Change Register to The Fours – The 400m Hills of England – 400m Sub-Fours appears below with the reclassifications to the list being detailed chronologically in receding order.




Change Register

The Fours – The 400m Hills of England

400m Sub-Fours





Reilth Top    404.6m at SO 28458 88105


Gathering data with the Trimble GeoXH 6000 at the summit of Reilth Top which resulted in this hill's reclassification to 400m Sub-Four status and which was later confirmed through analysis of LIDAR data

This hill’s reclassification to a 400m Sub-Four was announced on the Mapping Mountains site on 25.04.17, with the Hill Reclassifications post appearing on Mapping Mountains on the 27.04.17.  The hill had previously been listed as a Four with c 30m of drop based on an estimated summit height of c 406m with uppermost ring contouring of 405m on Ordnance Survey 1:25,000 Explorer maps and an estimated col height of c 376m with col contouring between 375m – 380m.  The hill was subsequently surveyed on the 25.03.17 by Myrddyn Phillips with the Trimble GeoXH 6000 resulting in a 404.6m summit and 375.6m col height which gives this hill 29.0m of drop which is insufficient for its continued status as a Four.  Once in receipt of these details Aled Williams then analysed them against LIDAR data resulting in a 404.6m summit and 375.3m col height which gives this hill 29.3m of drop.  400m Sub-Four total increases by one and confirmed as 155.





6th January 2014 – Haroldstreet publishes The Fours. 

400m Sub-Four total confirmed as 154.




15th December 2013 – Europeaklist publishes The Fours. 

400m Sub-Four total confirmed as 154.






Myrddyn Phillips and Aled Williams (February 2017)



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