diff --git a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C
index 796cb0983a..5421b328d8 100644
--- a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C
+++ b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C
@@ -31,7 +31,11 @@ License
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
-void Foam::mapDistribute::calcSchedule() const
+Foam::List<Foam::labelPair> Foam::mapDistribute::schedule
+(
+    const labelListList& subMap,
+    const labelListList& constructMap
+)
 {
     // Communications: send and receive processor
     List<labelPair> allComms;
@@ -40,16 +44,16 @@ void Foam::mapDistribute::calcSchedule() const
         HashSet<labelPair, labelPair::Hash<> > commsSet(Pstream::nProcs());
 
         // Find what communication is required
-        forAll(subMap_, procI)
+        forAll(subMap, procI)
         {
             if (procI != Pstream::myProcNo())
             {
-                if (subMap_[procI].size() > 0)
+                if (subMap[procI].size() > 0)
                 {
                     // I need to send to procI
                     commsSet.insert(labelPair(Pstream::myProcNo(), procI));
                 }
-                if (constructMap_[procI].size() > 0)
+                if (constructMap[procI].size() > 0)
                 {
                     // I need to receive from procI
                     commsSet.insert(labelPair(procI, Pstream::myProcNo()));
@@ -120,13 +124,7 @@ void Foam::mapDistribute::calcSchedule() const
     );
 
     // Processors involved in my schedule
-    schedulePtr_.reset
-    (
-        new List<labelPair>
-        (
-            IndirectList<labelPair>(allComms, mySchedule)
-        )
-    );
+    return IndirectList<labelPair>(allComms, mySchedule);
 
 
     //if (debug)
@@ -152,6 +150,22 @@ void Foam::mapDistribute::calcSchedule() const
 }
 
 
+const Foam::List<Foam::labelPair>& Foam::mapDistribute::schedule() const
+{
+    if (!schedulePtr_.valid())
+    {
+        schedulePtr_.reset
+        (
+            new List<labelPair>
+            (
+                schedule(subMap_, constructMap_)
+            )
+        );
+    }
+    return schedulePtr_();
+}
+
+
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 //- Construct from components
@@ -257,13 +271,4 @@ Foam::mapDistribute::mapDistribute
 }
 
 
-// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
-
-
-// * * * * * * * * * * * * * * * Friend Functions  * * * * * * * * * * * * * //
-
-
-// * * * * * * * * * * * * * * * Friend Operators  * * * * * * * * * * * * * //
-
-
 // ************************************************************************* //
diff --git a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.H b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.H
index bdc71c286d..65888ea79e 100644
--- a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.H
+++ b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.H
@@ -36,6 +36,8 @@ Note:
     Schedule is a list of processor pairs (one send, one receive. One of
     them will be myself) which forms a scheduled (i.e. non-buffered) exchange.
     See distribute on how to use it.
+    Note2: number of items send on one processor have to equal the number
+    of items received on the other processor.
 
 
 SourceFiles
@@ -80,8 +82,6 @@ class mapDistribute
 
     // Private Member Functions
 
-        void calcSchedule() const;
-
         //- Disallow default bitwise copy construct
         mapDistribute(const mapDistribute&);
 
@@ -142,15 +142,15 @@ public:
                 return constructMap_;
             }
 
+            //- Calculate a schedule. See above.
+            static List<labelPair> schedule
+            (
+                const labelListList& subMap,
+                const labelListList& constructMap
+            );
+
             //- Return a schedule. Demand driven. See above.
-            const List<labelPair>& schedule() const
-            {
-                if (!schedulePtr_.valid())
-                {
-                    calcSchedule();
-                }
-                return schedulePtr_();
-            }
+            const List<labelPair>& schedule() const;
 
 
         // Other
diff --git a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistributeTemplates.C b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistributeTemplates.C
index 86ee3d96cf..6ad85c7971 100644
--- a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistributeTemplates.C
+++ b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistributeTemplates.C
@@ -48,15 +48,28 @@ void Foam::mapDistribute::distribute
         // Send sub field to neighbour
         for (label domain = 0; domain < Pstream::nProcs(); domain++)
         {
-            if (domain != Pstream::myProcNo())
+            const labelList& map = subMap[domain];
+
+            if (domain != Pstream::myProcNo() && map.size() > 0)
             {
+                List<T> subField(map.size());
+                forAll(map, i)
+                {
+                    subField[i] = field[map[i]];
+                }
                 OPstream toNbr(Pstream::blocking, domain);
-                toNbr << IndirectList<T>(field, subMap[domain])();
+                toNbr << subField;
             }
         }
 
         // Subset myself
-        List<T> subField(IndirectList<T>(field, subMap[Pstream::myProcNo()]));
+        const labelList& mySubMap = subMap[Pstream::myProcNo()];
+
+        List<T> subField(mySubMap.size());
+        forAll(mySubMap, i)
+        {
+            subField[i] = field[mySubMap[i]];
+        }
 
         // Receive sub field from myself (subField)
         const labelList& map = constructMap[Pstream::myProcNo()];
@@ -71,7 +84,11 @@ void Foam::mapDistribute::distribute
         // Receive sub field from neighbour
         for (label domain = 0; domain < Pstream::nProcs(); domain++)
         {
-            if (domain != Pstream::myProcNo())
+            if
+            (
+                domain != Pstream::myProcNo()
+             && constructMap[domain].size() > 0
+            )
             {
                 IPstream fromNbr(Pstream::blocking, domain);
                 List<T> subField(fromNbr);
@@ -93,7 +110,13 @@ void Foam::mapDistribute::distribute
         List<T> newField(constructSize);
 
         // Subset myself
-        List<T> subField(IndirectList<T>(field, subMap[Pstream::myProcNo()]));
+        const labelList& mySubMap = subMap[Pstream::myProcNo()];
+
+        List<T> subField(mySubMap.size());
+        forAll(mySubMap, i)
+        {
+            subField[i] = field[mySubMap[i]];
+        }
 
         // Receive sub field from myself (subField)
         const labelList& map = constructMap[Pstream::myProcNo()];
@@ -112,8 +135,16 @@ void Foam::mapDistribute::distribute
             if (Pstream::myProcNo() == sendProc)
             {
                 // I am sender. Send to recvProc.
+                const labelList& map = subMap[recvProc];
+
+                List<T> subField(map.size());
+                forAll(map, i)
+                {
+                    subField[i] = field[map[i]];
+                }
+
                 OPstream toNbr(Pstream::scheduled, recvProc);
-                toNbr << IndirectList<T>(field, subMap[recvProc])();
+                toNbr << subField;
             }
             else
             {
@@ -136,7 +167,13 @@ void Foam::mapDistribute::distribute
         List<T> newField(constructSize);
 
         // Subset myself
-        List<T> subField(IndirectList<T>(field, subMap[Pstream::myProcNo()]));
+        const labelList& mySubMap = subMap[Pstream::myProcNo()];
+
+        List<T> subField(mySubMap.size());
+        forAll(mySubMap, i)
+        {
+            subField[i] = field[mySubMap[i]];
+        }
 
         // Receive sub field from myself (subField)
         const labelList& map = constructMap[Pstream::myProcNo()];
@@ -149,10 +186,19 @@ void Foam::mapDistribute::distribute
         // Send sub field to neighbour
         for (label domain = 0; domain < Pstream::nProcs(); domain++)
         {
-            if (domain != Pstream::myProcNo())
+            const labelList& map = subMap[domain];
+
+            if (domain != Pstream::myProcNo() && map.size() > 0)
             {
+
+                List<T> subField(map.size());
+                forAll(map, i)
+                {
+                    subField[i] = field[map[i]];
+                }
+
                 OPstream toNbr(Pstream::nonBlocking, domain);
-                toNbr << IndirectList<T>(field, subMap[domain])();
+                toNbr << subField;
             }
         }
 
@@ -160,13 +206,13 @@ void Foam::mapDistribute::distribute
         // Receive sub field from neighbour
         for (label domain = 0; domain < Pstream::nProcs(); domain++)
         {
-            if (domain != Pstream::myProcNo())
+            const labelList& map = constructMap[domain];
+
+            if (domain != Pstream::myProcNo() && map.size() > 0)
             {
                 IPstream fromNbr(Pstream::nonBlocking, domain);
                 List<T> subField(fromNbr);
 
-                const labelList& map = constructMap[domain];
-
                 forAll(map, i)
                 {
                     newField[map[i]] = subField[i];