Hello,

My understanding it that this requires making two sets of centerline data, then creating a survey for each set.  One of the data sets is for that part of the cave which has walls/scraps and the other is for the remainder of the cave.

The thconfig file is set up with only one survey/endsurvey section.  I think this also would have to change into two sections.

Is this correct?

No. Usually each results of real survey trip is added to cave centerline as a separate block of `survey...endsurvey`, and then it can be displayed on a map either with walls or as a centerline.

The map may contain both surveys and other maps.

The cave I want to do this for has all centerline data in one big file. It would be a huge pain to separate that into two files.  Even more of a pain would be moving the data as sketching is completed.

In this case there will be only one "survey" of whole cave.

For maps covered with scraps (walls) only partially I use the following method

=============

input cave.th # your centerline as is

map my_centerline
  survey1.cave
  survey2.cave

  # OR (if no subsurveys exists)

  cave
endmap

input map1.th2
input map2.th2

map my_whole_map
  map1
  map2
endmap

map my_whole_map_WIP
  my_whole_map
  break
  my_centerline
endmap

=============

-- 
  WBR, Vasily