Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Creators/Input/SlipPlaneUpliftVanCreator.cs
===================================================================
diff -u -r566943640717a91ff377a58a341bbbe1bcd2e516 -r526ac79e431d2a09d771bea0c7783c8562074de7
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Creators/Input/SlipPlaneUpliftVanCreator.cs	(.../SlipPlaneUpliftVanCreator.cs)	(revision 566943640717a91ff377a58a341bbbe1bcd2e516)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Creators/Input/SlipPlaneUpliftVanCreator.cs	(.../SlipPlaneUpliftVanCreator.cs)	(revision 526ac79e431d2a09d771bea0c7783c8562074de7)
@@ -56,23 +56,27 @@
                 kernelSlipPlane.SlipPlaneLeftGrid = CreateGrid(slipPlane.LeftGrid);
                 kernelSlipPlane.SlipPlaneRightGrid = CreateGrid(slipPlane.RightGrid);
             }
-            if (!slipPlane.TangentLinesAutomaticAtBoundaries)
-            {
-                kernelSlipPlane.SlipPlaneTangentLine = CreateTangentline(slipPlane);
-            }
 
+            kernelSlipPlane.SlipPlaneTangentLine = CreateTangentline(slipPlane);
+
             return kernelSlipPlane;
         }
 
         private static SlipCircleTangentLine CreateTangentline(UpliftVanSlipPlane slipPlane)
         {
-            return new SlipCircleTangentLine
+            var tangentLine = new SlipCircleTangentLine
             {
-                AutomaticAtBoundaries = slipPlane.TangentLinesAutomaticAtBoundaries,
-                TangentLineZTop = slipPlane.TangentZTop,
-                TangentLineZBottom = slipPlane.TangentZBottom,
-                TangentLineNumber = slipPlane.TangentLineNumber
+                AutomaticAtBoundaries = slipPlane.TangentLinesAutomaticAtBoundaries
             };
+
+            if (!slipPlane.TangentLinesAutomaticAtBoundaries)
+            {
+                tangentLine.TangentLineZTop = slipPlane.TangentZTop;
+                tangentLine.TangentLineZBottom = slipPlane.TangentZBottom;
+                tangentLine.TangentLineNumber = slipPlane.TangentLineNumber;
+            }
+
+            return tangentLine;
         }
 
         private static SlipCircleGrid CreateGrid(UpliftVanGrid grid)
Index: Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Creators/Input/SlipPlaneUpliftVanCreatorTest.cs
===================================================================
diff -u -r10e060be0b77c159b3e99a7200e43c4326b17642 -r526ac79e431d2a09d771bea0c7783c8562074de7
--- Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Creators/Input/SlipPlaneUpliftVanCreatorTest.cs	(.../SlipPlaneUpliftVanCreatorTest.cs)	(revision 10e060be0b77c159b3e99a7200e43c4326b17642)
+++ Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Creators/Input/SlipPlaneUpliftVanCreatorTest.cs	(.../SlipPlaneUpliftVanCreatorTest.cs)	(revision 526ac79e431d2a09d771bea0c7783c8562074de7)
@@ -108,8 +108,73 @@
             // Assert
             Assert.AreEqual(ActiveSideType.Left, slipPlaneUpliftVan.ActiveSide);
             Assert.IsNotNull(slipPlaneUpliftVan.SlipPlaneLeftGrid);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridXLeft);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridXRight);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridZTop);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridZBottom);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridXNumber);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridZNumber);
             Assert.IsNotNull(slipPlaneUpliftVan.SlipPlaneRightGrid);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneRightGrid.GridXLeft);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneRightGrid.GridXRight);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneRightGrid.GridZTop);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneRightGrid.GridZBottom);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneRightGrid.GridXNumber);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneRightGrid.GridZNumber);
             Assert.IsNotNull(slipPlaneUpliftVan.SlipPlaneTangentLine);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneTangentLine.TangentLineZTop);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneTangentLine.TangentLineZBottom);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneTangentLine.TangentLineNumber);
+            Assert.AreEqual(slipPlane.TangentLinesAutomaticAtBoundaries, slipPlaneUpliftVan.SlipPlaneTangentLine.AutomaticAtBoundaries);
         }
+
+        [Test]
+        public void Create_SlipPlaneTangentLinesAutomaticAtBoundaries_ReturnSlipPlaneUpliftVan()
+        {
+            // Setup
+            var random = new Random(21);
+            var leftGridXLeft = new RoundedDouble(2, random.NextDouble());
+            var leftGridXRight = new RoundedDouble(2, random.NextDouble());
+            var leftGridZTop = new RoundedDouble(2, random.NextDouble());
+            var leftGridZBottom = new RoundedDouble(2, random.NextDouble());
+            int leftGridXNumber = random.Next();
+            int leftGridZNumber = random.Next();
+            var rightGridXLeft = new RoundedDouble(2, random.NextDouble());
+            var rightGridXRight = new RoundedDouble(2, random.NextDouble());
+            var rightGridZTop = new RoundedDouble(2, random.NextDouble());
+            var rightGridZBottom = new RoundedDouble(2, random.NextDouble());
+            int rightGridXNumber = random.Next();
+            int rightGridZNumber = random.Next();
+
+            var leftGrid = new UpliftVanGrid(leftGridXLeft, leftGridXRight, leftGridZTop, leftGridZBottom, leftGridXNumber, leftGridZNumber);
+            var rightGrid = new UpliftVanGrid(rightGridXLeft, rightGridXRight, rightGridZTop, rightGridZBottom, rightGridXNumber, rightGridZNumber);
+            var slipPlane = new UpliftVanSlipPlane(leftGrid, rightGrid);
+
+            // Call
+            SlipPlaneUpliftVan slipPlaneUpliftVan = SlipPlaneUpliftVanCreator.Create(slipPlane);
+
+            // Assert
+            Assert.AreEqual(ActiveSideType.Left, slipPlaneUpliftVan.ActiveSide);
+            Assert.AreEqual(leftGridXLeft, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridXLeft);
+            Assert.AreEqual(leftGridXRight, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridXRight);
+            Assert.AreEqual(leftGridZTop, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridZTop);
+            Assert.AreEqual(leftGridZBottom, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridZBottom);
+            Assert.AreEqual(leftGridXNumber, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridXNumber);
+            Assert.AreEqual(leftGridZNumber, slipPlaneUpliftVan.SlipPlaneLeftGrid.GridZNumber);
+            Assert.AreSame(slipPlaneUpliftVan, slipPlaneUpliftVan.SlipPlaneLeftGrid.Owner); // Automatically synced
+            Assert.AreEqual(rightGridXLeft, slipPlaneUpliftVan.SlipPlaneRightGrid.GridXLeft);
+            Assert.AreEqual(rightGridXRight, slipPlaneUpliftVan.SlipPlaneRightGrid.GridXRight);
+            Assert.AreEqual(rightGridZTop, slipPlaneUpliftVan.SlipPlaneRightGrid.GridZTop);
+            Assert.AreEqual(rightGridZBottom, slipPlaneUpliftVan.SlipPlaneRightGrid.GridZBottom);
+            Assert.AreEqual(rightGridXNumber, slipPlaneUpliftVan.SlipPlaneRightGrid.GridXNumber);
+            Assert.AreEqual(rightGridZNumber, slipPlaneUpliftVan.SlipPlaneRightGrid.GridZNumber);
+            Assert.AreSame(slipPlaneUpliftVan, slipPlaneUpliftVan.SlipPlaneRightGrid.Owner); // Automatically synced
+            Assert.AreEqual(slipPlane.TangentLinesAutomaticAtBoundaries, slipPlaneUpliftVan.SlipPlaneTangentLine.AutomaticAtBoundaries);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneTangentLine.TangentLineZTop);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneTangentLine.TangentLineZBottom);
+            Assert.AreEqual(0, slipPlaneUpliftVan.SlipPlaneTangentLine.TangentLineNumber);
+            Assert.AreSame(slipPlaneUpliftVan, slipPlaneUpliftVan.SlipCircleTangentLine.TangentLinesBoundaries); // Automatically synced
+            Assert.AreEqual(10, slipPlaneUpliftVan.SlipPlaneTangentLine.MaxSpacingBetweenBoundaries); // Only used in case of auto grid determination combined with specified tangent lines (unsupported by calculator)
+        }
     }
 }
\ No newline at end of file