diff --git a/core/models_survex.py b/core/models_survex.py
index ed581a3..3bae04c 100644
--- a/core/models_survex.py
+++ b/core/models_survex.py
@@ -97,7 +97,7 @@ class SurvexBlockLookUpManager(models.Manager):
             blocknames = []
         else:
             blocknames = name.split(".")
-        block = SurvexBlock.objects.get(parent=None, survexfile__path="all")
+        block = SurvexBlock.objects.get(parent=None, survexfile__path=settings.SURVEX_TOPNAME)
         for blockname in blocknames:
             block = SurvexBlock.objects.get(parent=block, name__iexact=blockname)
         return block
diff --git a/parsers/survex.py b/parsers/survex.py
index a999c43..294de73 100644
--- a/parsers/survex.py
+++ b/parsers/survex.py
@@ -249,7 +249,7 @@ def LoadAllSurvexBlocks():
 
     print(" - Data flushed")
 
-    survexfile = models.SurvexFile(path="all", cave=None)
+    survexfile = models.SurvexFile(path=settings.SURVEX_TOPNAME, cave=None)
     survexfile.save()
     survexfile.SetDirectory()
 
@@ -281,9 +281,9 @@ def LoadPos():
 
     print('Loading Pos....')
 
-    call([settings.CAVERN, "--output=%s/all.3d" % settings.SURVEX_DATA, "%s/all.svx" % settings.SURVEX_DATA])
-    call([settings.THREEDTOPOS, '%sall.3d' % settings.SURVEX_DATA], cwd = settings.SURVEX_DATA)
-    posfile = open("%sall.pos" % settings.SURVEX_DATA)
+    call([settings.CAVERN, "--output=%s%s.3d" % (settings.SURVEX_DATA, settings.SURVEX_TOPNAME), "%s%s.svx" % (settings.SURVEX_DATA, settings.SURVEX_TOPNAME)])
+    call([settings.THREEDTOPOS, '%s%s.3d' % (settings.SURVEX_DATA, settings.SURVEX_TOPNAME)], cwd = settings.SURVEX_DATA)
+    posfile = open("%s%s.pos" % (settings.SURVEX_DATA, settings.SURVEX_TOPNAME))
     posfile.readline() #Drop header
     for line in posfile.readlines():
         r = poslineregex.match(line)                
diff --git a/settings.py b/settings.py
index 9770fd7..262b28e 100644
--- a/settings.py
+++ b/settings.py
@@ -53,6 +53,9 @@ SURVEYS_URL = urlparse.urljoin(URL_ROOT , '/survey_scans/')
 PHOTOS_URL  = urlparse.urljoin(URL_ROOT , '/photos/')
 SVX_URL = urlparse.urljoin(URL_ROOT , '/survex/')
 
+# top-level survex file basename (without .svx)
+SURVEX_TOPNAME = "1623"
+
 DEFAULT_LOGBOOK_PARSER = "Parseloghtmltxt"
 DEFAULT_LOGBOOK_FILE = "logbook.html"