Many paper survey notes are archived in Matienzo. It may be best to see these before starting any centre line construction. The survey may also have name(s) to consult as well. Original surveyors may also be holding survey notes or files. Filter with 'mm'.

A centre line cannot be constructed off these surveys as there is no indication of the north direction.

Filter with 'mr' to pick out sites for resurveying.
Many surveys may be just a plan or elevation so are unsuitable to go through the Survex reconstruction as there is no clues for altitude changes or shaft shape. Other 'surveys' may be a sketch with no North.
Such sites may be suitable for a resurvey although some may be classed as trivial. The length / depth on the table provides an indication; the shorter ones may be digs with potential. A number of these sites may be outside the current permit area and may not be 'ours' to (re)survey. Others may have going leads.
Some of the sites may be suitable for survey training purposes and some suitable for future cloud-point surveys using, e.g. Caveatron.
• Anyone wanting to resurvey or survey a particular site should discuss with Phil Papard to avoid duplication.

Sketches are most unlikely to be suitable for centre line construction so the site will either be small or require surveying. Filtering with 'ms' will pick out the sketches

Some of these surveys are decades old but, nevertheless, original survey material may still be available from individuals or caving groups. The list is not exhaustive. Material may also be stored in the Matienzo archive, especially the earlier numbers, before we went 'all digital'.
To filter for a person or group, type '+' then the code shown below.
+ADEMCO Asociacion Deportiva Espeleo y Montaña de Colindres
+AECL A. E. C. Lobetum (Cuenca)
+al Alf Latham
+CAEAP Colectivo para la Ampliación de Estudios de Arqueología Prehistórica
+GEIS Grupo de Espeleología e Investigaciones Subterráneas Carballo/Raba
+GES Grupo Espeleológico de Santander del C.A. Tajahierro
+gs Guy Simonnot (Spéléo Club de Dijon)
+lc Lloyd Cawthorne
+nd Nigel Dibben
+pp Phil Papard
+ rs Rupert Skorupka
+SEAD Sociedad Espeleológica Alto Duero
+ SCC Speleo Club Cántabro

   Filtering sites with a * will show those where a centre line could be reconstructed from the available survey. There may be additional codes which should be considered.
    There may also be sketches without a N direction that could be suitable if they are shown relative to a road or other feature that can be seen on a map.
• There may be further information hidden away in the logbooks. They can be searched.
• Anybody is very welcome to take on one or more caves - but please inform Juan juancorrin[at]matienzo.org.uk which you are claiming before you start.

• Some knowledge of using Inkscape is presumed although there are (slightly out-dated) help files to get you started.
• Inkscape : Download Version 1.2 and install it.
• Patrick Warren's Extension to Inkscape in a zip file: v3 for Inkscape : Read Me file (also in the zip file) in HTML or PDF
  - After unzipping the folder, follow the instructions in the ReadMe file to put the extension into the correct folder (2 files to copy/move). For Windows 10, the folder "%APPDATA%\inkscape\extensions\" is usually
"C:\Users\Your user folder\AppData\Roaming\inkscape\extensions\"
  - The ReadMe file contains a suggested work flow.

• Patrick would like suggestions for improvements to the Extension and/or the documentation. patrickbwarren[at]gmail.com
• With the information from the old surveys, as well as producing a centre line, it is also possible to add left, right, up, down data to the stations. A simple centre line is better than nothing, as long as reasonable Z data is available or can be deduced.
• It may be that, to produce a reasonable 3d file from the svx, extra legs have to be introduced, e.g. into originally unsurveyed rifts or up slopes, etc. Any new length calculation should take a common sense approach and possibly exclude such legs between *FLAGS SPLAYS and *FLAGS NOT SPLAYS.
• Each Survex file should be named nnnn-RCN.svx where nnnn is the site number and RCN indicates that the svx file is reconstructed both when viewed alone and within area or regional groups. "*BEGIN nnnn-RCN" should also be used in the svx file.