Index: src/Common/DelftTools.Utils/PropertyBag/Dynamic/DynamicPropertyBag.cs
===================================================================
diff -u -rc5c796f26bff6a1d0e3d4e1242d59e234dc73f6a -r9cd3db94455d7ac8ec96d2504f46ca66a203a724
--- src/Common/DelftTools.Utils/PropertyBag/Dynamic/DynamicPropertyBag.cs	(.../DynamicPropertyBag.cs)	(revision c5c796f26bff6a1d0e3d4e1242d59e234dc73f6a)
+++ src/Common/DelftTools.Utils/PropertyBag/Dynamic/DynamicPropertyBag.cs	(.../DynamicPropertyBag.cs)	(revision 9cd3db94455d7ac8ec96d2504f46ca66a203a724)
@@ -21,6 +21,14 @@
             Initialize(propertyObject, customPropertyInfos ?? propertyObject.GetType().GetProperties());
         }
 
+        public object WrappedObject
+        {
+            get
+            {
+                return propertyObject;
+            }
+        }
+
         public Type GetContentType()
         {
             return propertyObject.GetType();
Index: src/Plugins/Wti/Wti.Data/PipingSurfaceLine.cs
===================================================================
diff -u -rc42d0c47753135357002db6026ebbefc3603a62b -r9cd3db94455d7ac8ec96d2504f46ca66a203a724
--- src/Plugins/Wti/Wti.Data/PipingSurfaceLine.cs	(.../PipingSurfaceLine.cs)	(revision c42d0c47753135357002db6026ebbefc3603a62b)
+++ src/Plugins/Wti/Wti.Data/PipingSurfaceLine.cs	(.../PipingSurfaceLine.cs)	(revision 9cd3db94455d7ac8ec96d2504f46ca66a203a724)
@@ -52,5 +52,10 @@
                 EndingWorldPoint = point3Ds[point3Ds.Length - 1];
             }
         }
+
+        public override string ToString()
+        {
+            return Name;
+        }
     }
 }
\ No newline at end of file
Index: src/Plugins/Wti/Wti.Forms/PropertyClasses/PipingCalculationInputsProperties.cs
===================================================================
diff -u -rf65154bc499025f9f5b37b9de0ebdf8026336020 -r9cd3db94455d7ac8ec96d2504f46ca66a203a724
--- src/Plugins/Wti/Wti.Forms/PropertyClasses/PipingCalculationInputsProperties.cs	(.../PipingCalculationInputsProperties.cs)	(revision f65154bc499025f9f5b37b9de0ebdf8026336020)
+++ src/Plugins/Wti/Wti.Forms/PropertyClasses/PipingCalculationInputsProperties.cs	(.../PipingCalculationInputsProperties.cs)	(revision 9cd3db94455d7ac8ec96d2504f46ca66a203a724)
@@ -1,9 +1,14 @@
-using DelftTools.Shell.Gui;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Drawing.Design;
+
+using DelftTools.Shell.Gui;
 using DelftTools.Utils;
 
 using Wti.Data;
 using Wti.Forms.PresentationObjects;
 using Wti.Forms.Properties;
+using Wti.Forms.UITypeEditors;
 
 namespace Wti.Forms.PropertyClasses
 {
@@ -346,6 +351,7 @@
             }
         }
 
+        [Editor(typeof(PipingCalculationInputsSurfaceLineSelectionEditor), typeof(UITypeEditor))]
         [ResourcesCategory(typeof(Resources), "Categories_General")]
         [ResourcesDisplayName(typeof(Resources), "PipingDataSurfaceLineDisplayName")]
         [ResourcesDescription(typeof(Resources), "PipingDataSurfaceLineDescription")]
@@ -355,6 +361,19 @@
             {
                 return data.PipingData.SurfaceLine;
             }
+            set
+            {
+                data.PipingData.SurfaceLine = value;
+                data.PipingData.NotifyObservers();
+            }
         }
+
+        /// <summary>
+        /// Gets the available surface lines on <see cref="PipingCalculationInputs"/>.
+        /// </summary>
+        public IEnumerable<PipingSurfaceLine> GetAvailableSurfaceLines()
+        {
+            return data.AvailablePipingSurfaceLines;
+        }
     }
 }
\ No newline at end of file
Index: src/Plugins/Wti/Wti.Forms/UITypeEditors/PipingCalculationInputsSurfaceLineSelectionEditor.cs
===================================================================
diff -u
--- src/Plugins/Wti/Wti.Forms/UITypeEditors/PipingCalculationInputsSurfaceLineSelectionEditor.cs	(revision 0)
+++ src/Plugins/Wti/Wti.Forms/UITypeEditors/PipingCalculationInputsSurfaceLineSelectionEditor.cs	(revision 9cd3db94455d7ac8ec96d2504f46ca66a203a724)
@@ -0,0 +1,70 @@
+using System;
+using System.ComponentModel;
+using System.Drawing.Design;
+using System.Windows.Forms;
+using System.Windows.Forms.Design;
+
+using DelftTools.Utils.PropertyBag.Dynamic;
+using DelftTools.Utils.Reflection;
+
+using Wti.Data;
+using Wti.Forms.PropertyClasses;
+
+namespace Wti.Forms.UITypeEditors
+{
+    /// <summary>
+    /// This class defines a drop down list edit-control from which the user can select a
+    /// <see cref="PipingSurfaceLine"/> from a collection.
+    /// </summary>
+    public class PipingCalculationInputsSurfaceLineSelectionEditor : UITypeEditor
+    {
+        private IWindowsFormsEditorService editorService;
+
+        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
+        {
+            return UITypeEditorEditStyle.DropDown;
+        }
+
+        public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
+        {
+            if (provider != null)
+            {
+                editorService = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));
+            }
+
+            if (editorService != null)
+            {
+                // Create editor:
+                var listBox = CreateSurfaceLinesSelectionControl(context);
+
+                // Open editor for user to select an item:
+                editorService.DropDownControl(listBox);
+
+                // Return user selected object, or original value if user did not select anything:
+                return listBox.SelectedItem ?? value;
+            }
+            return base.EditValue(context, provider, value);
+        }
+
+        private ListBox CreateSurfaceLinesSelectionControl(ITypeDescriptorContext context)
+        {
+            var listBox = new ListBox
+            {
+                SelectionMode = SelectionMode.One,
+                DisplayMember = TypeUtils.GetMemberName<PipingSurfaceLine>(sl => sl.Name)
+            };
+            listBox.SelectedValueChanged += (sender, eventArgs) => editorService.CloseDropDown();
+
+            var properties = (PipingCalculationInputsProperties)((DynamicPropertyBag)context.Instance).WrappedObject;
+            foreach (var surfaceLine in properties.GetAvailableSurfaceLines())
+            {
+                int index = listBox.Items.Add(surfaceLine);
+                if (ReferenceEquals(properties.SurfaceLine, surfaceLine))
+                {
+                    listBox.SelectedIndex = index;
+                }
+            }
+            return listBox;
+        }
+    }
+}
\ No newline at end of file
Index: src/Plugins/Wti/Wti.Forms/Wti.Forms.csproj
===================================================================
diff -u -rf65154bc499025f9f5b37b9de0ebdf8026336020 -r9cd3db94455d7ac8ec96d2504f46ca66a203a724
--- src/Plugins/Wti/Wti.Forms/Wti.Forms.csproj	(.../Wti.Forms.csproj)	(revision f65154bc499025f9f5b37b9de0ebdf8026336020)
+++ src/Plugins/Wti/Wti.Forms/Wti.Forms.csproj	(.../Wti.Forms.csproj)	(revision 9cd3db94455d7ac8ec96d2504f46ca66a203a724)
@@ -73,6 +73,7 @@
     <Compile Include="PropertyClasses\PipingOutputProperties.cs" />
     <Compile Include="PropertyClasses\PipingSurfaceLineProperties.cs" />
     <Compile Include="PropertyClasses\WtiProjectProperties.cs" />
+    <Compile Include="UITypeEditors\PipingCalculationInputsSurfaceLineSelectionEditor.cs" />
     <Service Include="{94E38DFF-614B-4cbd-B67C-F211BB35CE8B}" />
   </ItemGroup>
   <ItemGroup>
Index: test/Plugins/Wti/Wti.Data.Test/PipingSurfaceLineTest.cs
===================================================================
diff -u -rab8c3b732c3aaadc8e55be98e132bdaf41110169 -r9cd3db94455d7ac8ec96d2504f46ca66a203a724
--- test/Plugins/Wti/Wti.Data.Test/PipingSurfaceLineTest.cs	(.../PipingSurfaceLineTest.cs)	(revision ab8c3b732c3aaadc8e55be98e132bdaf41110169)
+++ test/Plugins/Wti/Wti.Data.Test/PipingSurfaceLineTest.cs	(.../PipingSurfaceLineTest.cs)	(revision 9cd3db94455d7ac8ec96d2504f46ca66a203a724)
@@ -61,5 +61,22 @@
             Assert.AreSame(sourceData[0], surfaceLine.StartingWorldPoint);
             Assert.AreSame(sourceData[0], surfaceLine.EndingWorldPoint);
         }
+
+        [Test]
+        public void ToString_ReturnName()
+        {
+            // Setup
+            const string niceName = "Nice name";
+            var surfaceLine = new PipingSurfaceLine
+            {
+                Name = niceName
+            };
+
+            // Call
+            var text = surfaceLine.ToString();
+
+            // Assert
+            Assert.AreEqual(niceName, text);
+        }
     }
 }
\ No newline at end of file
Index: test/Plugins/Wti/Wti.Forms.Test/UITypeEditors/PipingCalculationInputsSurfaceLineSelectionEditorTest.cs
===================================================================
diff -u
--- test/Plugins/Wti/Wti.Forms.Test/UITypeEditors/PipingCalculationInputsSurfaceLineSelectionEditorTest.cs	(revision 0)
+++ test/Plugins/Wti/Wti.Forms.Test/UITypeEditors/PipingCalculationInputsSurfaceLineSelectionEditorTest.cs	(revision 9cd3db94455d7ac8ec96d2504f46ca66a203a724)
@@ -0,0 +1,35 @@
+using System.Drawing.Design;
+
+using NUnit.Framework;
+
+using Wti.Forms.UITypeEditors;
+
+namespace Wti.Forms.Test.UITypeEditors
+{
+    [TestFixture]
+    public class PipingCalculationInputsSurfaceLineSelectionEditorTest
+    {
+        [Test]
+        public void DefaultConstructor_ExpectedValues()
+        {
+            // Call
+            var editor = new PipingCalculationInputsSurfaceLineSelectionEditor();
+
+            // Assert
+            Assert.IsInstanceOf<UITypeEditor>(editor);
+        }
+
+        [Test]
+        public void GetEditStyle_Always_ReturnDropDown()
+        {
+            // Setup
+            var editor = new PipingCalculationInputsSurfaceLineSelectionEditor();
+
+            // Call
+            var editStyle = editor.GetEditStyle();
+
+            // Assert
+            Assert.AreEqual(UITypeEditorEditStyle.DropDown, editStyle);
+        }
+    }
+}
\ No newline at end of file
Index: test/Plugins/Wti/Wti.Forms.Test/Wti.Forms.Test.csproj
===================================================================
diff -u -rf65154bc499025f9f5b37b9de0ebdf8026336020 -r9cd3db94455d7ac8ec96d2504f46ca66a203a724
--- test/Plugins/Wti/Wti.Forms.Test/Wti.Forms.Test.csproj	(.../Wti.Forms.Test.csproj)	(revision f65154bc499025f9f5b37b9de0ebdf8026336020)
+++ test/Plugins/Wti/Wti.Forms.Test/Wti.Forms.Test.csproj	(.../Wti.Forms.Test.csproj)	(revision 9cd3db94455d7ac8ec96d2504f46ca66a203a724)
@@ -62,6 +62,7 @@
     <Compile Include="PropertyClasses\PipingOutputPropertiesTest.cs" />
     <Compile Include="PropertyClasses\PipingSurfaceLinePropertiesTest.cs" />
     <Compile Include="PropertyClasses\WtiProjectPropertiesTest.cs" />
+    <Compile Include="UITypeEditors\PipingCalculationInputsSurfaceLineSelectionEditorTest.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\..\..\src\Common\DelftTools.Controls.Swf\DelftTools.Controls.Swf.csproj">