diff --git a/src/OpenFOAM/db/IOobjects/decomposedBlockData/decomposedBlockData.C b/src/OpenFOAM/db/IOobjects/decomposedBlockData/decomposedBlockData.C
index 32f8f5f142..24e190d79e 100644
--- a/src/OpenFOAM/db/IOobjects/decomposedBlockData/decomposedBlockData.C
+++ b/src/OpenFOAM/db/IOobjects/decomposedBlockData/decomposedBlockData.C
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2017-2018 OpenFOAM Foundation
+    Copyright (C) 2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -30,7 +31,6 @@ License
 #include "IPstream.H"
 #include "PstreamBuffers.H"
 #include "Fstream.H"
-#include "StringStream.H"
 #include "dictionary.H"
 #include "objectRegistry.H"
 #include "SubList.H"
@@ -160,12 +160,6 @@ Foam::decomposedBlockData::decomposedBlockData
 }
 
 
-// * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * * //
-
-Foam::decomposedBlockData::~decomposedBlockData()
-{}
-
-
 // * * * * * * * * * * * * * * * Members Functions * * * * * * * * * * * * * //
 
 bool Foam::decomposedBlockData::readMasterHeader(IOobject& io, Istream& is)
@@ -181,15 +175,11 @@ bool Foam::decomposedBlockData::readMasterHeader(IOobject& io, Istream& is)
 
     List<char> data(is);
     is.fatalCheck("read(Istream&) : reading entry");
-    IListStream str
-    (
-        std::move(data),
-        IOstream::ASCII,
-        IOstream::currentVersion,
-        is.name()
-    );
 
-    return io.readHeader(str);
+    UIListStream headerStream(data);
+    headerStream.name() = is.name();
+
+    return io.readHeader(headerStream);
 }
 
 
@@ -254,24 +244,15 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlock
 
     is.fatalCheck("read(Istream&)");
 
-    List<char> data;
     autoPtr<ISstream> realIsPtr;
 
     if (blocki == 0)
     {
-        is >> data;
+        List<char> data(is);
         is.fatalCheck("read(Istream&) : reading entry");
 
-        realIsPtr.reset
-        (
-            new IListStream
-            (
-                std::move(data),
-                IOstream::ASCII,
-                IOstream::currentVersion,
-                is.name()
-            )
-        );
+        realIsPtr.reset(new IListStream(std::move(data)));
+        realIsPtr->name() = is.name();
 
         // Read header
         if (!headerIO.readHeader(realIsPtr()))
@@ -284,7 +265,7 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlock
     else
     {
         // Read master for header
-        is >> data;
+        List<char> data(is);
         is.fatalCheck("read(Istream&) : reading entry");
 
         IOstream::versionNumber ver(IOstream::currentVersion);
@@ -292,13 +273,7 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlock
         unsigned labelByteSize;
         unsigned scalarByteSize;
         {
-            UIListStream headerStream
-            (
-                data,
-                IOstream::ASCII,
-                IOstream::currentVersion,
-                is.name()
-            );
+            UIListStream headerStream(data);
 
             // Read header
             if (!headerIO.readHeader(headerStream))
@@ -315,20 +290,12 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlock
 
         for (label i = 1; i < blocki+1; i++)
         {
-            // Read data, override old data
+            // Read and discard data, only retain the last one
             is >> data;
             is.fatalCheck("read(Istream&) : reading entry");
         }
-        realIsPtr.reset
-        (
-            new IListStream
-            (
-                std::move(data),
-                IOstream::ASCII,
-                IOstream::currentVersion,
-                is.name()
-            )
-        );
+        realIsPtr.reset(new IListStream(std::move(data)));
+        realIsPtr->name() = is.name();
 
         // Apply master stream settings to realIsPtr
         realIsPtr().format(fmt);
@@ -336,6 +303,7 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlock
         realIsPtr().setLabelByteSize(labelByteSize);
         realIsPtr().setScalarByteSize(scalarByteSize);
     }
+
     return realIsPtr;
 }
 
@@ -358,22 +326,6 @@ bool Foam::decomposedBlockData::readBlocks
 
     bool ok = false;
 
-
-
-    //// Scatter master header info
-    //string ver;
-    //unsigned labelByteSize;
-    //unsigned scalarByteSize;
-    //if (UPstream::master(comm))
-    //{
-    //    ver = isPtr().version().str();
-    //    labelByteSize = isPtr().labelByteSize();
-    //    scalarByteSize = isPtr().scalarByteSize();
-    //}
-    //Pstream::scatter(ver); //,  Pstream::msgType(), comm);
-    //Pstream::scatter(labelByteSize); //,  Pstream::msgType(), comm);
-    //Pstream::scatter(scalarByteSize); //,  Pstream::msgType(), comm);
-
     if (commsType == UPstream::commsTypes::scheduled)
     {
         if (UPstream::master(comm))
@@ -509,17 +461,8 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlocks
                 is >> data;
                 is.fatalCheck("read(Istream&) : reading entry");
 
-                realIsPtr.reset
-                (
-                    new IListStream
-                    (
-                        std::move(data),
-                        IOstream::ASCII,
-                        IOstream::currentVersion,
-                        fName
-                    )
-                );
-
+                realIsPtr.reset(new IListStream(std::move(data)));
+                realIsPtr->name() = fName;
 
                 // Read header
                 if (!headerIO.readHeader(realIsPtr()))
@@ -566,16 +509,8 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlocks
             );
             is >> data;
 
-            realIsPtr.reset
-            (
-                new IListStream
-                (
-                    std::move(data),
-                    IOstream::ASCII,
-                    IOstream::currentVersion,
-                    fName
-                )
-            );
+            realIsPtr.reset(new IListStream(std::move(data)));
+            realIsPtr->name() = fName;
         }
     }
     else
@@ -597,16 +532,8 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlocks
                 is >> data;
                 is.fatalCheck("read(Istream&) : reading entry");
 
-                realIsPtr.reset
-                (
-                    new IListStream
-                    (
-                        std::move(data),
-                        IOstream::ASCII,
-                        IOstream::currentVersion,
-                        fName
-                    )
-                );
+                realIsPtr.reset(new IListStream(std::move(data)));
+                realIsPtr->name() = fName;
 
                 // Read header
                 if (!headerIO.readHeader(realIsPtr()))
@@ -643,16 +570,8 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlocks
             UIPstream is(UPstream::masterNo(), pBufs);
             is >> data;
 
-            realIsPtr.reset
-            (
-                new IListStream
-                (
-                    std::move(data),
-                    IOstream::ASCII,
-                    IOstream::currentVersion,
-                    fName
-                )
-            );
+            realIsPtr.reset(new IListStream(std::move(data)));
+            realIsPtr->name() = fName;
         }
     }
 
@@ -661,26 +580,24 @@ Foam::autoPtr<Foam::ISstream> Foam::decomposedBlockData::readBlocks
     //- Set stream properties from realIsPtr on master
 
     // Scatter master header info
-    string ver;
-    string format;
+    string versionString;
+    label formatValue;
     unsigned labelByteSize;
     unsigned scalarByteSize;
     if (UPstream::master(comm))
     {
-        ver = realIsPtr().version().str();
-        OStringStream os;
-        os << realIsPtr().format();
-        format = os.str();
+        versionString = realIsPtr().version().str();
+        formatValue = static_cast<label>(realIsPtr().format());
         labelByteSize = realIsPtr().labelByteSize();
         scalarByteSize = realIsPtr().scalarByteSize();
     }
-    Pstream::scatter(ver); //,  Pstream::msgType(), comm);
-    Pstream::scatter(format); //,  Pstream::msgType(), comm);
+    Pstream::scatter(versionString); //,  Pstream::msgType(), comm);
+    Pstream::scatter(formatValue); //,  Pstream::msgType(), comm);
     Pstream::scatter(labelByteSize); //,  Pstream::msgType(), comm);
     Pstream::scatter(scalarByteSize); //,  Pstream::msgType(), comm);
 
-    realIsPtr().version(IOstream::versionNumber(ver));
-    realIsPtr().format(format);
+    realIsPtr().version(IOstream::versionNumber(versionString));
+    realIsPtr().format(IOstream::streamFormat(formatValue));
     realIsPtr().setLabelByteSize(labelByteSize);
     realIsPtr().setScalarByteSize(scalarByteSize);
 
@@ -1072,30 +989,17 @@ bool Foam::decomposedBlockData::writeData(Ostream& os) const
     // Re-read my own data to find out the header information
     if (Pstream::master(comm_))
     {
-        UIListStream is
-        (
-            data,
-            IOstream::ASCII,
-            IOstream::currentVersion,
-            name()
-        );
-        io.readHeader(is);
+        UIListStream headerStream(data);
+        io.readHeader(headerStream);
     }
 
     // Scatter header information
 
-    // version
     string versionString(os.version().str());
     Pstream::scatter(versionString, Pstream::msgType(), comm_);
 
-    // stream
-    string formatString;
-    {
-        OStringStream os;
-        os << os.format();
-        formatString  = os.str();
-        Pstream::scatter(formatString, Pstream::msgType(), comm_);
-    }
+    label formatValue(os.format());
+    Pstream::scatter(formatValue, Pstream::msgType(), comm_);
 
     //word masterName(name());
     //Pstream::scatter(masterName, Pstream::msgType(), comm_);
@@ -1114,7 +1018,7 @@ bool Foam::decomposedBlockData::writeData(Ostream& os) const
         (
             os,
             IOstream::versionNumber(versionString),
-            IOstream::formatEnum(formatString),
+            IOstream::streamFormat(formatValue),
             io.headerClassName(),
             io.note(),
             masterLocation,
@@ -1122,12 +1026,18 @@ bool Foam::decomposedBlockData::writeData(Ostream& os) const
         );
     }
 
-    string str
-    (
-        reinterpret_cast<const char*>(data.cbegin()),
-        data.byteSize()
-    );
-    os.writeQuoted(str, false);
+    // Write the character data
+    if (isA<OFstream>(os))
+    {
+        // Serial file output - can use writeRaw()
+        os.writeRaw(data.cdata(), data.byteSize());
+    }
+    else
+    {
+        // Other cases are less fortunate, and no std::string_view
+        std::string str(data.cdata(), data.byteSize());
+        os.writeQuoted(str, false);
+    }
 
     if (!Pstream::master(comm_))
     {
diff --git a/src/OpenFOAM/db/IOobjects/decomposedBlockData/decomposedBlockData.H b/src/OpenFOAM/db/IOobjects/decomposedBlockData/decomposedBlockData.H
index 026287ceac..8ce5aeccba 100644
--- a/src/OpenFOAM/db/IOobjects/decomposedBlockData/decomposedBlockData.H
+++ b/src/OpenFOAM/db/IOobjects/decomposedBlockData/decomposedBlockData.H
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2017-2018 OpenFOAM Foundation
+    Copyright (C) 2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -57,7 +58,7 @@ class decomposedBlockData
 {
 protected:
 
-    // Protected data
+    // Protected Data
 
         //- Type to use for gather
         const UPstream::commsTypes commsType_;
@@ -90,6 +91,7 @@ protected:
 
 public:
 
+    //- Declare type-name, virtual type (with debug switch)
     TypeName("decomposedBlockData");
 
 
@@ -123,7 +125,7 @@ public:
 
 
     //- Destructor
-    virtual ~decomposedBlockData();
+    virtual ~decomposedBlockData() = default;
 
 
     // Member functions
@@ -133,7 +135,7 @@ public:
 
         //- Write separated content. Assumes content is the serialised data
         //  and that the master data contains a header
-        virtual bool writeData(Ostream&) const;
+        virtual bool writeData(Ostream& os) const;
 
         //- Write using stream options
         virtual bool writeObject
@@ -224,7 +226,7 @@ public:
         );
 
         //- Detect number of blocks in a file
-        static label numBlocks(const fileName&);
+        static label numBlocks(const fileName& fName);
 };
 
 
diff --git a/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C b/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C
index c3f065b040..fb0595f583 100644
--- a/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C
+++ b/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C
@@ -494,93 +494,71 @@ bool Foam::fileOperations::masterUncollatedFileOperation::uniformFile
 void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
 (
     const fileName& filePath,
-    const IOstream::compressionType cmp,
     const labelUList& procs,
     PstreamBuffers& pBufs
 )
 {
-    if (cmp == IOstream::compressionType::COMPRESSED)
+    IFstream ifs(filePath, IOstream::streamFormat::BINARY);
+
+    if (!ifs.good())
     {
-        if (debug)
-        {
-            Pout<< "masterUncollatedFileOperation::readAndSend :"
-                << " Opening compressed " << filePath << endl;
-        }
-
-        IFstream is(filePath, IOstream::streamFormat::BINARY);
-
-        if (!is.good())
-        {
-            FatalIOErrorInFunction(filePath) << "Cannot open file " << filePath
-                << exit(FatalIOError);
-        }
-
-        std::ostringstream stringStr;
-        stringStr << is.stdStream().rdbuf();
-        string buf(stringStr.str());
-
-        forAll(procs, i)
-        {
-            UOPstream os(procs[i], pBufs);
-            os.write(&buf[0], buf.size());
-        }
+        FatalIOErrorInFunction(filePath)
+            << "Cannot open file " << filePath
+            << exit(FatalIOError);
     }
-    else
+
+    if (debug)
     {
-        off_t count(Foam::fileSize(filePath));
-        IFstream is(filePath, IOstream::streamFormat::BINARY);
+        Pout<< "masterUncollatedFileOperation::readAndSend :"
+            << " compressed:" << bool(ifs.compression()) << " "
+            << filePath << endl;
+    }
 
-        if (!is.good())
+    if (ifs.compression() == IOstream::compressionType::COMPRESSED)
+    {
+        // Could use Foam::fileSize, estimate uncompressed size (eg, 2x)
+        // and then string reserve followed by string assign...
+
+        // Uncompress and read file contents into a character buffer
+        const std::string buf
+        (
+            std::istreambuf_iterator<char>(ifs.stdStream()),
+            std::istreambuf_iterator<char>()
+        );
+
+        for (const label proci : procs)
         {
-            FatalIOErrorInFunction(filePath) << "Cannot open file " << filePath
-                << exit(FatalIOError);
+            UOPstream os(proci, pBufs);
+            os.write(buf.data(), buf.length());
         }
 
-
         if (debug)
         {
             Pout<< "masterUncollatedFileOperation::readStream :"
-                << " From " << filePath <<  " reading " << label(count)
+                << " From " << filePath <<  " sent " << buf.size()
                 << " bytes" << endl;
         }
-        List<char> buf(static_cast<label>(count));
-        is.stdStream().read(buf.begin(), count);
-
-        forAll(procs, i)
-        {
-            UOPstream os(procs[i], pBufs);
-            os.write(buf.begin(), count);
-        }
-    }
-}
-
-
-void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
-(
-    const fileName& fName,
-    const labelUList& procs,
-    PstreamBuffers& pBufs
-)
-{
-    if (Foam::exists(fName+".gz", false))
-    {
-        readAndSend
-        (
-            fName,
-            IOstream::compressionType::COMPRESSED,
-            procs,
-            pBufs
-        );
     }
     else
     {
-        readAndSend
-        (
-            fName,
-            IOstream::compressionType::UNCOMPRESSED,
-            procs,
-            pBufs
-        );
+        const off_t count(Foam::fileSize(filePath));
+
+        // Read file contents into a character buffer
+        List<char> buf(static_cast<label>(count));
+        ifs.stdStream().read(buf.data(), count);
+
+        for (const label proci : procs)
+        {
+            UOPstream os(proci, pBufs);
+            os.write(buf.cdata(), count);
+        }
+
+        if (debug)
+        {
+            Pout<< "masterUncollatedFileOperation::readStream :"
+                << " From " << filePath <<  " sent " << buf.size()
+                << " bytes" << endl;
+        }
     }
 }
 
@@ -656,18 +634,16 @@ Foam::fileOperations::masterUncollatedFileOperation::read
                         << exit(FatalIOError);
                 }
 
-                autoPtr<IFstream> ifsPtr(new IFstream(filePaths[0]));
+                // Open master
+                isPtr.reset(new IFstream(filePaths[0]));
 
                 // Read header
-                if (!io.readHeader(ifsPtr()))
+                if (!io.readHeader(isPtr()))
                 {
-                    FatalIOErrorInFunction(ifsPtr())
+                    FatalIOErrorInFunction(isPtr())
                         << "problem while reading header for object "
                         << io.name() << exit(FatalIOError);
                 }
-
-                // Open master (steal from ifsPtr)
-                isPtr.reset(ifsPtr.ptr());
             }
 
             // Read slave files
@@ -715,7 +691,7 @@ Foam::fileOperations::masterUncollatedFileOperation::read
             List<char> buf(recvSizes[Pstream::masterNo()]);
             if (recvSizes[Pstream::masterNo()] > 0)
             {
-                is.read(buf.begin(), recvSizes[Pstream::masterNo()]);
+                is.read(buf.data(), recvSizes[Pstream::masterNo()]);
             }
 
             if (debug)
@@ -723,17 +699,15 @@ Foam::fileOperations::masterUncollatedFileOperation::read
                 Pout<< "masterUncollatedFileOperation::readStream :"
                     << " Done reading " << buf.size() << " bytes" << endl;
             }
-            const fileName& fName = filePaths[Pstream::myProcNo(comm)];
-            isPtr.reset
-            (
-                new IListStream
-                (
-                    std::move(buf),
-                    IOstream::BINARY,
-                    IOstream::currentVersion,
-                    fName
-                )
-            );
+
+            // A local character buffer copy of the Pstream contents.
+            // Construct with same parameters (ASCII, current version)
+            // as the IFstream so that it has the same characteristics.
+
+            isPtr.reset(new IListStream(std::move(buf)));
+
+            // With the proper file name
+            isPtr->name() = filePaths[Pstream::myProcNo(comm)];
 
             if (!io.readHeader(isPtr()))
             {
@@ -1424,6 +1398,7 @@ Foam::fileName Foam::fileOperations::masterUncollatedFileOperation::dirPath
             {
                 // Retest all processors separately since some processors might
                 // have the file and some not (e.g. lagrangian data)
+
                 objPath = masterOp<fileName, fileOrNullOp>
                 (
                     io.objectPath(),
@@ -1721,7 +1696,7 @@ Foam::fileOperations::masterUncollatedFileOperation::readObjects
     {
         // Avoid fileOperation::readObjects from triggering parallel ops
         // (through call to filePath which triggers parallel )
-        bool oldParRun = UPstream::parRun();
+        const bool oldParRun = UPstream::parRun();
         UPstream::parRun() = false;
 
         //- Use non-time searching version
@@ -1872,8 +1847,8 @@ bool Foam::fileOperations::masterUncollatedFileOperation::readHeader
                              == decomposedBlockData::typeName
                             )
                             {
-                                // Read the header inside the container (master
-                                // data)
+                                // Read the header inside the container
+                                // (master data)
                                 result[proci] = decomposedBlockData::
                                 readMasterHeader
                                 (
@@ -2003,7 +1978,6 @@ Foam::fileOperations::masterUncollatedFileOperation::readStream
         );
 
 
-        List<char> data;
         if (!Pstream::parRun())
         {
             // Analyse the objectpath to find out the processor we're trying
@@ -2038,20 +2012,6 @@ Foam::fileOperations::masterUncollatedFileOperation::readStream
         }
         else
         {
-            // Scatter master header info
-            //string versionString;
-            //string formatString;
-            //if (isPtr.valid())
-            //{
-            //    versionString = isPtr().version().str();
-            //    OStringStream os;
-            //    os << isPtr().format();
-            //    formatString = (os.str());
-            //}
-            //
-            //Pstream::scatter(versionString); //,  Pstream::msgType(), comm);
-            //Pstream::scatter(formatString); //,  Pstream::msgType(), comm);
-
             // Get size of file
             off_t sz = Foam::fileSize(fName);
             bool bigSize = sz > off_t(maxMasterFileBufferSize);
@@ -2131,7 +2091,7 @@ Foam::fileOperations::masterUncollatedFileOperation::readStream
             Pstream::gatherList(procValid, Pstream::msgType(), comm_);
 
             // Uniform in local comm
-            bool uniform = uniformFile(filePaths);
+            const bool uniform = uniformFile(filePaths);
 
             return read(io, comm_, uniform, filePaths, procValid);
         }
@@ -2161,7 +2121,7 @@ bool Foam::fileOperations::masterUncollatedFileOperation::read
         if (Pstream::master())  // comm_))
         {
             // Do master-only reading always.
-            bool oldParRun = UPstream::parRun();
+            const bool oldParRun = UPstream::parRun();
             UPstream::parRun() = false;
 
             ok = io.readData(io.readStream(typeName));
@@ -2307,7 +2267,7 @@ Foam::instantList Foam::fileOperations::masterUncollatedFileOperation::findTimes
         if (Pstream::master())  // comm_))
         {
             // Do master-only reading always.
-            bool oldParRun = UPstream::parRun();
+            const bool oldParRun = UPstream::parRun();
             UPstream::parRun() = false;
             times = fileOperation::findTimes(directory, constantName);
             UPstream::parRun() = oldParRun;
@@ -2343,6 +2303,8 @@ void Foam::fileOperations::masterUncollatedFileOperation::setTime
     }
 
     // Mutable access to instantList for modification and sorting
+    // - cannot use auto type deduction here
+
     HashPtrTable<instantList>::iterator iter = times_.find(tm.path());
 
     if (iter.found())
@@ -2351,48 +2313,40 @@ void Foam::fileOperations::masterUncollatedFileOperation::setTime
 
         const instant timeNow(tm.value(), tm.timeName());
 
-        if (times.size() > 0 && times[0].name() == tm.constant())
-        {
-            // Exclude constant
-            SubList<instant> realTimes(times, times.size()-1, 1);
-            if
+        // Exclude constant when checking and sorting
+        const label skipConst =
+        (
+            (!times.empty() && times[0].name() == tm.constant())
+          ? 1
+          : 0
+        );
+
+        if
+        (
+            findSortedIndex
             (
-                findSortedIndex
-                (
-                    SubList<instant>(times, times.size()-1, 1),
-                    timeNow
-                )
-             == -1
+                SubList<instant>(times, times.size()-skipConst, skipConst),
+                timeNow
             )
-            {
-                if (debug)
-                {
-                    Pout<< "masterUncollatedFileOperation::setTime :"
-                        << " Caching time " << tm.timeName()
-                        << " for case:" << tm.path() << endl;
-                }
-
-                times.append(timeNow);
-                SubList<instant> realTimes(times, times.size()-1, 1);
-                Foam::stableSort(realTimes);
-            }
-        }
-        else
+         == -1
+        )
         {
-            if (findSortedIndex(times, timeNow) == -1)
+            if (debug)
             {
-                if (debug)
-                {
-                    Pout<< "masterUncollatedFileOperation::setTime :"
-                        << " Caching time " << tm.timeName()
-                        << " for case:" << tm.path() << endl;
-                }
-
-                times.append(timeNow);
-                Foam::stableSort(times);
+                Pout<< "masterUncollatedFileOperation::setTime :"
+                    << " Caching time " << tm.timeName()
+                    << " for case:" << tm.path() << endl;
             }
+
+            times.append(timeNow);
+            SubList<instant> realTimes
+            (
+                times, times.size()-skipConst, skipConst
+            );
+            Foam::stableSort(realTimes);
         }
     }
+
     fileOperation::setTime(tm);
 }
 
@@ -2403,6 +2357,8 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
     const fileName& filePath
 ) const
 {
+    autoPtr<ISstream> isPtr;
+
     if (Pstream::parRun())
     {
         // Insert logic of filePath. We assume that if a file is absolute
@@ -2431,25 +2387,12 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
                         << " Opening global file " << filePath << endl;
                 }
 
-                IOstream::compressionType cmp
+                readAndSend
                 (
-                    Foam::exists(filePath+".gz", false)
-                  ? IOstream::compressionType::COMPRESSED
-                  : IOstream::compressionType::UNCOMPRESSED
+                    filePath,
+                    identity(Pstream::nProcs(Pstream::worldComm)-1, 1),
+                    pBufs
                 );
-
-                labelList procs(Pstream::nProcs(Pstream::worldComm)-1);
-                for
-                (
-                    label proci = 1;
-                    proci < Pstream::nProcs(Pstream::worldComm);
-                    proci++
-                )
-                {
-                    procs[proci-1] = proci;
-                }
-
-                readAndSend(filePath, cmp, procs, pBufs);
             }
             else
             {
@@ -2460,17 +2403,9 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
                     proci++
                 )
                 {
-                    IOstream::compressionType cmp
-                    (
-                        Foam::exists(filePaths[proci]+".gz", false)
-                      ? IOstream::compressionType::COMPRESSED
-                      : IOstream::compressionType::UNCOMPRESSED
-                    );
-
                     readAndSend
                     (
                         filePaths[proci],
-                        cmp,
                         labelList(1, proci),
                         pBufs
                     );
@@ -2485,10 +2420,7 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
         if (Pstream::master(Pstream::worldComm))
         {
             // Read myself
-            return autoPtr<ISstream>
-            (
-                new IFstream(filePaths[Pstream::masterNo()])
-            );
+            isPtr.reset(new IFstream(filePaths[Pstream::masterNo()]));
         }
         else
         {
@@ -2502,7 +2434,7 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
             UIPstream is(Pstream::masterNo(), pBufs);
 
             List<char> buf(recvSizes[Pstream::masterNo()]);
-            is.read(buf.begin(), buf.size());
+            is.read(buf.data(), buf.size());
 
             if (debug)
             {
@@ -2510,26 +2442,23 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
                     << " Done reading " << buf.size() << " bytes" << endl;
             }
 
-            // Note: IPstream is not an IStream so use a IStringStream to
-            //       convert the buffer. Note that we construct with a string
-            //       so it holds a copy of the buffer.
-            return autoPtr<ISstream>
-            (
-                new IListStream
-                (
-                    std::move(buf),
-                    IOstream::BINARY,
-                    IOstream::currentVersion,
-                    filePath
-                )
-            );
+            // A local character buffer copy of the Pstream contents.
+            // Construct with same parameters (ASCII, current version)
+            // as the IFstream so that it has the same characteristics.
+
+            isPtr.reset(new IListStream(std::move(buf)));
+
+            // With the proper file name
+            isPtr->name() = filePath;
         }
     }
     else
     {
         // Read myself
-        return autoPtr<ISstream>(new IFstream(filePath));
+        isPtr.reset(new IFstream(filePath));
     }
+
+    return isPtr;
 }
 
 
diff --git a/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H b/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H
index ee068b5c32..03ccd0fd61 100644
--- a/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H
+++ b/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H
@@ -448,20 +448,11 @@ protected:
             const word& instancePath
         ) const;
 
-        //- Read file contents and send to processors
+        //- Read file contents and send to processors.
+        //  Handles compressed or uncompressed files
         static void readAndSend
         (
             const fileName& filePath,
-            const IOstream::compressionType cmp,
-            const labelUList& procs,
-            PstreamBuffers& pBufs
-        );
-
-        //- Detect file (possibly compressed), read file contents and send
-        //  to processors
-        static void readAndSend
-        (
-            const fileName& fName,
             const labelUList& procs,
             PstreamBuffers& pBufs
         );