Index: Ringtoets/Piping/src/Ringtoets.Piping.Plugin/PipingGuiPlugin.cs
===================================================================
diff -u -rc9fd032c799e1325decbec83d99e94851a954816 -r6a1df79cc36617a42d0016f9b7a9271020a2196e
--- Ringtoets/Piping/src/Ringtoets.Piping.Plugin/PipingGuiPlugin.cs	(.../PipingGuiPlugin.cs)	(revision c9fd032c799e1325decbec83d99e94851a954816)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Plugin/PipingGuiPlugin.cs	(.../PipingGuiPlugin.cs)	(revision 6a1df79cc36617a42d0016f9b7a9271020a2196e)
@@ -131,12 +131,12 @@
                                                                                  .Build()
             };
 
-            yield return new TreeNodeInfo<IEnumerable<RingtoetsPipingSurfaceLine>>
+            yield return new TreeNodeInfo<RingtoetsPipingSurfaceLineContext>
             {
                 Text = ringtoetsPipingSurfaceLine => PipingFormsResources.PipingSurfaceLinesCollection_DisplayName,
                 Image = ringtoetsPipingSurfaceLine => PipingFormsResources.FolderIcon,
-                ForeColor = ringtoetsPipingSurfaceLine => ringtoetsPipingSurfaceLine.Any() ? Color.FromKnownColor(KnownColor.ControlText) : Color.FromKnownColor(KnownColor.GrayText),
-                ChildNodeObjects = ringtoetsPipingSurfaceLine => ringtoetsPipingSurfaceLine.Cast<object>().ToArray(),
+                ForeColor = ringtoetsPipingSurfaceLine => ringtoetsPipingSurfaceLine.FailureMechanism.SurfaceLines.Any() ? Color.FromKnownColor(KnownColor.ControlText) : Color.FromKnownColor(KnownColor.GrayText),
+                ChildNodeObjects = ringtoetsPipingSurfaceLine => ringtoetsPipingSurfaceLine.FailureMechanism.SurfaceLines.Cast<object>().ToArray(),
                 ContextMenuStrip = (nodeData, parentData, treeViewControl) => Gui.Get(nodeData, treeViewControl)
                                                                                  .AddImportItem()
                                                                                  .AddExportItem()
@@ -374,7 +374,7 @@
             return new ArrayList
             {
                 new FailureMechanismSectionsContext(failureMechanism, assessmentSection),
-                failureMechanism.SurfaceLines,
+                new RingtoetsPipingSurfaceLineContext(failureMechanism, assessmentSection),
                 failureMechanism.SoilProfiles,
                 failureMechanism.BoundaryConditions
             };