diff --git a/src/OpenFOAM/algorithms/AABBTree/AABBTree.C b/src/OpenFOAM/algorithms/AABBTree/AABBTree.C
index 8bbac68837..b6aad91f74 100644
--- a/src/OpenFOAM/algorithms/AABBTree/AABBTree.C
+++ b/src/OpenFOAM/algorithms/AABBTree/AABBTree.C
@@ -116,7 +116,7 @@ void Foam::AABBTree<Type>::createBoxes
             {
                 if (isUsedPoint.set(pointI))
                 {
-                    component.append(points[pointI][maxDir]);
+                    component.push_back(points[pointI][maxDir]);
                 }
             }
         }
@@ -167,12 +167,12 @@ void Foam::AABBTree<Type>::createBoxes
         // if it crosses the bin boundaries
         if (addMin)
         {
-            minBinObjectIDs.append(objI);
+            minBinObjectIDs.push_back(objI);
             minBb.add(points, obj);
         }
         if (addMax)
         {
-            maxBinObjectIDs.append(objI);
+            maxBinObjectIDs.push_back(objI);
             maxBb.add(points, obj);
         }
     }
@@ -209,13 +209,13 @@ void Foam::AABBTree<Type>::createBoxes
     {
         // New leaf
         minI = nodes.size();
-        nodes.append(labelPair(-1, -1));
+        nodes.emplace_back(-1, -1);
     }
     else
     {
         // Update existing leaf
         minI = -addressing.size() - 1;
-        addressing.append(minBinObjectIDs);
+        addressing.push_back(minBinObjectIDs);
     }
 
     label maxI;
@@ -223,13 +223,13 @@ void Foam::AABBTree<Type>::createBoxes
     {
         // New leaf
         maxI = nodes.size();
-        nodes.append(labelPair(-1, -1));
+        nodes.emplace_back(-1, -1);
     }
     else
     {
         // Update existing leaf
         maxI = -addressing.size() - 1;
-        addressing.append(maxBinObjectIDs);
+        addressing.push_back(maxBinObjectIDs);
     }
 
     nodes(nodeI) = labelPair(minI, maxI);
@@ -308,7 +308,7 @@ Foam::AABBTree<Type>::AABBTree
     DynamicList<labelPair> nodes(maxLevel);
     DynamicList<labelList> addr(maxLevel);
 
-    nodes.append(labelPair(-1, -1));
+    nodes.emplace_back(-1, -1);
     treeBoundBox topBb(points);
     topBb.inflate(0.01);
 
@@ -356,13 +356,13 @@ Foam::AABBTree<Type>::AABBTree
     {
         if (nodes[nodeI].first() < 0)
         {
-            boundBoxes.append(bbs[nodeI].first());
-            addressing.append(addr[-(nodes[nodeI].first() + 1)]);
+            boundBoxes.push_back(bbs[nodeI].first());
+            addressing.push_back(addr[-(nodes[nodeI].first() + 1)]);
         }
         if (nodes[nodeI].second() < 0)
         {
-            boundBoxes.append(bbs[nodeI].second());
-            addressing.append(addr[-(nodes[nodeI].second() + 1)]);
+            boundBoxes.push_back(bbs[nodeI].second());
+            addressing.push_back(addr[-(nodes[nodeI].second() + 1)]);
         }
     }
 
diff --git a/src/OpenFOAM/algorithms/dynamicIndexedOctree/dynamicIndexedOctree.C b/src/OpenFOAM/algorithms/dynamicIndexedOctree/dynamicIndexedOctree.C
index db767a72d1..f60afd763f 100644
--- a/src/OpenFOAM/algorithms/dynamicIndexedOctree/dynamicIndexedOctree.C
+++ b/src/OpenFOAM/algorithms/dynamicIndexedOctree/dynamicIndexedOctree.C
@@ -56,7 +56,7 @@ void Foam::dynamicIndexedOctree<Type>::divide
         {
             if (shapes_.overlaps(index, subBbs))
             {
-                contains.append(index);
+                contains.push_back(index);
             }
         }
     }
@@ -117,7 +117,7 @@ Foam::dynamicIndexedOctree<Type>::divide
             {
                 // Append to contents
                 contentIndex = contents_.size();
-                contents_.append(std::move(subIndices));
+                contents_.push_back(std::move(subIndices));
             }
 
             nod.subNodes_[octant] = contentPlusOctant(contentIndex, octant);
@@ -136,7 +136,7 @@ Foam::dynamicIndexedOctree<Type>::divide
 
         const label newNodeId = nodes_.size();
 
-        nodes_.append(nod);
+        nodes_.push_back(nod);
 
         nodes_[parentNodeIndex].subNodes_[octantToBeDivided]
             = nodePlusOctant(newNodeId, octantToBeDivided);
@@ -2463,13 +2463,12 @@ bool Foam::dynamicIndexedOctree<Type>::insert(label startIndex, label endIndex)
 
     if (nodes_.empty())
     {
-        contents_.append(DynamicList<label>(1));
-        contents_[0].append(0);
+        contents_.emplace_back(1).push_back(0);
 
         // Create topnode.
         node topNode = divide(bb_, 0, -1, 0);
 
-        nodes_.append(topNode);
+        nodes_.push_back(topNode);
 
         startIndex++;
     }
@@ -2528,7 +2527,7 @@ bool Foam::dynamicIndexedOctree<Type>::insertIndex
             {
                 const label contentI = getContent(subNodeLabel);
 
-                contents_[contentI].append(index);
+                contents_[contentI].push_back(index);
 
                 recursiveSubDivision
                 (
@@ -2548,11 +2547,9 @@ bool Foam::dynamicIndexedOctree<Type>::insertIndex
 
             if (shapes().overlaps(index, subBb))
             {
-                label sz = contents_.size();
+                const label sz = contents_.size();
 
-                contents_.append(DynamicList<label>(1));
-
-                contents_[sz].append(index);
+                contents_.emplace_back(1).push_back(index);
 
                 nodes_[nodIndex].subNodes_[octant]
                     = contentPlusOctant(sz, octant);
@@ -2635,7 +2632,7 @@ Foam::label Foam::dynamicIndexedOctree<Type>::removeIndex
 
                     if (oldIndex != index)
                     {
-                        newContent.append(oldIndex);
+                        newContent.push_back(oldIndex);
                     }
                 }
 
diff --git a/src/OpenFOAM/algorithms/indexedOctree/indexedOctree.C b/src/OpenFOAM/algorithms/indexedOctree/indexedOctree.C
index 30f0f2d679..b75d9dfbf5 100644
--- a/src/OpenFOAM/algorithms/indexedOctree/indexedOctree.C
+++ b/src/OpenFOAM/algorithms/indexedOctree/indexedOctree.C
@@ -55,7 +55,7 @@ void Foam::indexedOctree<Type>::divide
         {
             if (shapes_.overlaps(index, subBbs))
             {
-                contains.append(index);
+                contains.push_back(index);
             }
         }
 
@@ -117,7 +117,7 @@ Foam::indexedOctree<Type>::divide
             {
                 // Append to contents
                 contentIndex = contents.size();
-                contents.append(std::move(subIndices));
+                contents.push_back(std::move(subIndices));
             }
 
             nod.subNodes_[octant] = contentPlusOctant(contentIndex, octant);
@@ -171,7 +171,7 @@ void Foam::indexedOctree<Type>::splitNodes
                     node subNode(divide(bb, contents, contentI));
                     subNode.parent_ = nodeI;
                     label sz = nodes.size();
-                    nodes.append(subNode);
+                    nodes.push_back(subNode);
                     nodes[nodeI].subNodes_[octant] = nodePlusOctant(sz, octant);
                 }
             }
@@ -2172,11 +2172,11 @@ Foam::indexedOctree<Type>::indexedOctree
     // Start off with one node with all shapes in it.
     DynamicList<node> nodes(label(shapes.size() / maxLeafRatio));
     DynamicList<labelList> contents(label(shapes.size() / maxLeafRatio));
-    contents.append(identity(shapes.size()));
+    contents.push_back(identity(shapes.size()));
 
     // Create topnode.
     node topNode(divide(bb, contents, 0));
-    nodes.append(topNode);
+    nodes.push_back(topNode);
 
 
     // Now have all contents at level 1. Create levels by splitting levels