diff --git a/cdm/src/main/java/ucar/nc2/iosp/netcdf3/N3iosp.java b/cdm/src/main/java/ucar/nc2/iosp/netcdf3/N3iosp.java
index e39e6d9..e6159f6 100644
--- a/cdm/src/main/java/ucar/nc2/iosp/netcdf3/N3iosp.java
+++ b/cdm/src/main/java/ucar/nc2/iosp/netcdf3/N3iosp.java
@@ -410,6 +410,23 @@ public String NC_check_name(String name) {
     this.fill = fill;
   }
 
+  /**
+   * Returns a Layout object for use by an N3iosp object
+   *
+   * @param v2 the variable to get the layout information for
+   * @param section the record range to read
+   * @return a Layout corresponding to the Section requested
+   * @throws IOException on error
+   */
+  private Layout getLayout(Variable v2, Section section) throws InvalidRangeException {
+    N3header.Vinfo vinfo = (N3header.Vinfo) v2.getSPobject();
+
+    Layout layout = (!v2.isUnlimited()) ? new LayoutRegular(vinfo.begin, v2.getElementSize(), v2.getShape(), section) 
+      : new LayoutRegularSegmented(vinfo.begin, v2.getElementSize(), header.recsize, v2.getShape(), section);
+
+    return layout;
+  }
+
   /////////////////////////////////////////////////////////////////////////////
   // data reading
 
@@ -417,11 +434,8 @@ public String NC_check_name(String name) {
     if (v2 instanceof Structure)
       return readRecordData((Structure) v2, section);
 
-    N3header.Vinfo vinfo = (N3header.Vinfo) v2.getSPobject();
     DataType dataType = v2.getDataType();
-
-    Layout layout = (!v2.isUnlimited()) ? new LayoutRegular(vinfo.begin, v2.getElementSize(), v2.getShape(), section) :
-      new LayoutRegularSegmented(vinfo.begin, v2.getElementSize(), header.recsize, v2.getShape(), section);
+    Layout layout = getLayout(v2, section);
 
     if (layout.getTotalNelems() == 0) {
       return Array.factory(dataType.getPrimitiveClassType(), section.getShape());
@@ -563,11 +577,8 @@ public String NC_check_name(String name) {
     if (v2 instanceof Structure)
       return readRecordData((Structure) v2, section, channel);
 
-    N3header.Vinfo vinfo = (N3header.Vinfo) v2.getSPobject();
     DataType dataType = v2.getDataType();
-
-    Layout layout = (!v2.isUnlimited()) ? new LayoutRegular(vinfo.begin, v2.getElementSize(), v2.getShape(), section) :
-      new LayoutRegularSegmented(vinfo.begin, v2.getElementSize(), header.recsize, v2.getShape(), section);
+    Layout layout = getLayout(v2, section);
 
     return readData(layout, dataType, channel);
   }
@@ -662,7 +673,6 @@ public String NC_check_name(String name) {
 
   public void writeData(Variable v2, Section section, Array values) throws java.io.IOException, InvalidRangeException {
 
-    N3header.Vinfo vinfo = (N3header.Vinfo) v2.getSPobject();
     DataType dataType = v2.getDataType();
 
     if (v2.isUnlimited()) {
@@ -674,8 +684,7 @@ public String NC_check_name(String name) {
       writeRecordData((Structure) v2, section, values);
 
     } else {
-      Layout layout = (!v2.isUnlimited()) ? new LayoutRegular(vinfo.begin, v2.getElementSize(), v2.getShape(), section) :
-        new LayoutRegularSegmented(vinfo.begin, v2.getElementSize(), header.recsize, v2.getShape(), section);
+      Layout layout = getLayout(v2, section);
       writeData(values, layout, dataType);
     }
   }