diff --git a/Cards/Powheg/NewTests/TWminustoLNu2Q_powheg-herwig7/TWminustoLNu2Q_powheg-herwig7.json b/Cards/Powheg/NewTests/TWminustoLNu2Q_powheg-herwig7/TWminustoLNu2Q_powheg-herwig7.json
new file mode 100644
index 00000000..f99ceac1
--- /dev/null
+++ b/Cards/Powheg/NewTests/TWminustoLNu2Q_powheg-herwig7/TWminustoLNu2Q_powheg-herwig7.json
@@ -0,0 +1,14 @@
+{
+    "gridpack_submit": false,
+    "gridpack_path": "SingleT/ST_wtch_DR_slc7_amd64_gcc10_CMSSW_12_4_8_TWminustoLNu2Q_powheg-pythia8.tgz",
+
+    "fragment": ["Generator/ExternalLHEProducer_Powheg.dat","PartonShower/powheg-herwig7.dat","Filter/OneLepton.dat"],
+    "fragment_user": [],
+    "fragment_vars": {
+        "processParameters": [
+        ],
+        "additionalCommands" : [
+           "postGenerationCommand = cms.untracked.vstring('mergeLHE.py', '-i', 'thread*/cmsgrid_final.lhe', '-o', 'cmsgrid_final.lhe')"
+        ]
+    }
+}
diff --git a/Fragments/Generator/ExternalLHEProducer_Powheg.dat b/Fragments/Generator/ExternalLHEProducer_Powheg.dat
index d47ebdc1..c0a43d03 100644
--- a/Fragments/Generator/ExternalLHEProducer_Powheg.dat
+++ b/Fragments/Generator/ExternalLHEProducer_Powheg.dat
@@ -6,6 +6,7 @@ externalLHEProducer = cms.EDProducer('ExternalLHEProducer',
     numberOfParameters = cms.uint32(1),
     outputFile = cms.string('cmsgrid_final.lhe'),
     scriptName = cms.FileInPath('GeneratorInterface/LHEInterface/data/run_generic_tarball_cvmfs.sh'),
-    generateConcurrently = cms.untracked.bool($concurrentLHEforPowheg)
+    generateConcurrently = cms.untracked.bool($concurrentLHEforPowheg),
+    $additionalCommands
 )
 
diff --git a/Fragments/PartonShower/powheg-herwig7.dat b/Fragments/PartonShower/powheg-herwig7.dat
new file mode 100644
index 00000000..63f5aa10
--- /dev/null
+++ b/Fragments/PartonShower/powheg-herwig7.dat
@@ -0,0 +1,36 @@
+import FWCore.ParameterSet.Config as cms
+
+from Configuration.Generator.Herwig7Settings.Herwig7LHECommonSettings_cfi import *
+from Configuration.Generator.Herwig7Settings.Herwig7StableParticlesForDetector_cfi import *
+from Configuration.Generator.Herwig7Settings.Herwig7$tuneTuneSettings_cfi import *
+from Configuration.Generator.Herwig7Settings.Herwig7LHEPowhegSettings_cfi import *
+from Configuration.Generator.Herwig7Settings.Herwig7_7p1SettingsFor7p2_cfi import *
+
+generator = cms.EDFilter("Herwig7GeneratorFilter",
+    herwig7LHECommonSettingsBlock,
+    herwig7LHEPowhegSettingsBlock,
+    herwig7p1SettingsFor7p2Block,
+    herwig7StableParticlesForDetectorBlock,
+    herwig7$tuneSettingsBlock,
+    configFiles = cms.vstring(),
+    dataLocation = cms.string('${HERWIGPATH}'),
+    eventHandlers = cms.string('/Herwig/EventHandlers'),
+    generatorModule = cms.string('/Herwig/Generators/EventGenerator'),    
+    hw_user_settings = cms.vstring(
+        'set /Herwig/EventHandlers/EventHandler:LuminosityFunction:Energy $comEnergy*GeV',
+        $processParameters
+    ),     
+    parameterSets = cms.vstring(
+        'hw_lhe_common_settings',
+        'hw_lhe_powheg_settings',
+        'hw_7p1SettingsFor7p2',
+        'herwig7$tunePDF', 
+        'herwig7$tuneAlphaS', 
+        'herwig7$tuneMPISettings', 
+        'herwig7StableParticlesForDetector',
+        'hw_user_settings'
+    ),
+    repository = cms.string('${HERWIGPATH}/HerwigDefaults.rpo'),
+    run = cms.string('InterfaceMatchboxTest'),
+    runModeList = cms.untracked.string('read,run'),
+)