diff --git a/CalibFormats/HcalObjects/src/HcalText2DetIdConverter.cc b/CalibFormats/HcalObjects/src/HcalText2DetIdConverter.cc
index 9db06d4d644fb..9efe4b2ab13e9 100644
--- a/CalibFormats/HcalObjects/src/HcalText2DetIdConverter.cc
+++ b/CalibFormats/HcalObjects/src/HcalText2DetIdConverter.cc
@@ -118,6 +118,7 @@ bool HcalText2DetIdConverter::init (DetId fId) {
     case HcalZDCDetId::EM: flavorName = "ZDC_EM"; break;
     case HcalZDCDetId::HAD: flavorName = "ZDC_HAD"; break;
     case HcalZDCDetId::LUM: flavorName = "ZDC_LUM"; break;
+    case HcalZDCDetId::RPD: flavorName = "ZDC_RPD"; break;
     default: result = false;
     }
     setField (1, zdcId.zside());
@@ -206,7 +207,8 @@ bool HcalText2DetIdConverter::init (const std::string& fFlavor, const std::strin
   else if (flavorName.find ("ZDC_") == 0) {
     HcalZDCDetId::Section section = flavorName == "ZDC_EM" ? HcalZDCDetId::EM :
       flavorName == "ZDC_HAD" ? HcalZDCDetId::HAD : 
-      flavorName == "ZDC_LUM" ? HcalZDCDetId::LUM : HcalZDCDetId::Unknown;
+      flavorName == "ZDC_LUM" ? HcalZDCDetId::LUM : 
+      flavorName == "ZDC_RPD" ? HcalZDCDetId::RPD : HcalZDCDetId::Unknown;
     mId = HcalZDCDetId (section, getField (1)>0, getField (2));
   }
   else if (flavorName.find ("CALIB_") == 0) {
diff --git a/CaloOnlineTools/HcalOnlineDb/src/HcalAssistant.cc b/CaloOnlineTools/HcalOnlineDb/src/HcalAssistant.cc
index edf3b118debd5..02f161e576f95 100644
--- a/CaloOnlineTools/HcalOnlineDb/src/HcalAssistant.cc
+++ b/CaloOnlineTools/HcalOnlineDb/src/HcalAssistant.cc
@@ -168,6 +168,7 @@ std::string HcalAssistant::getZDCSectionString(HcalZDCDetId::Section _section){
   if           ( _section==HcalZDCDetId::EM)   zdcSection = "ZDC EM";
   else if      ( _section==HcalZDCDetId::HAD)  zdcSection = "ZDC HAD";
   else if      ( _section==HcalZDCDetId::LUM)  zdcSection = "ZDC LUM";
+  else if      ( _section==HcalZDCDetId::RPD)  zdcSection = "ZDC RPD";
   else zdcSection = "UNKNOWN";
   return zdcSection;
 }
@@ -177,6 +178,7 @@ HcalZDCDetId::Section HcalAssistant::getZDCSection(std::string _section){
   if      ( _section.find("ZDC EM") != std::string::npos ) return HcalZDCDetId::EM;
   else if ( _section.find("ZDC HAD") != std::string::npos ) return HcalZDCDetId::HAD;
   else if ( _section.find("ZDC LUM") != std::string::npos ) return HcalZDCDetId::LUM;
+  else if ( _section.find("ZDC RPD") != std::string::npos ) return HcalZDCDetId::RPD;
   else return HcalZDCDetId::Unknown;
 }
 
diff --git a/CaloOnlineTools/HcalOnlineDb/src/HcalDbOmds.cc b/CaloOnlineTools/HcalOnlineDb/src/HcalDbOmds.cc
index 9d0b535d841a0..ece0077ea9ac4 100644
--- a/CaloOnlineTools/HcalOnlineDb/src/HcalDbOmds.cc
+++ b/CaloOnlineTools/HcalOnlineDb/src/HcalDbOmds.cc
@@ -963,6 +963,7 @@ HcalZDCDetId::Section HcalDbOmds::get_zdc_section( std::string _section )
   else if ( _section.find("EM") != std::string::npos )   result = HcalZDCDetId::EM;
   else if ( _section.find("HAD") != std::string::npos )  result = HcalZDCDetId::HAD;
   else if ( _section.find("LUM") != std::string::npos ) result = HcalZDCDetId::LUM;
+  else if ( _section.find("RPD") != std::string::npos ) result = HcalZDCDetId::RPD;
   else                                              result = HcalZDCDetId::Unknown;  
   
   return result;
diff --git a/CondFormats/HcalObjects/src/HcalMappingEntry.cc b/CondFormats/HcalObjects/src/HcalMappingEntry.cc
index 8f02529cf690e..63752ceb75189 100644
--- a/CondFormats/HcalObjects/src/HcalMappingEntry.cc
+++ b/CondFormats/HcalObjects/src/HcalMappingEntry.cc
@@ -315,6 +315,7 @@ ZDCLogicalMapEntry::ZDCLogicalMapEntry(
   if (in_s_det=="ZDC_EM") myzdcsec = HcalZDCDetId::EM;
   else if (in_s_det=="ZDC_HAD") myzdcsec = HcalZDCDetId::HAD;
   else if (in_s_det=="ZDC_LUM") myzdcsec = HcalZDCDetId::LUM;
+  else if (in_s_det=="ZDC_RPD") myzdcsec = HcalZDCDetId::RPD;
   else myzdcsec = HcalZDCDetId::Unknown;
  
   (in_sid > 0) ? myzdccheck = true : myzdccheck = false;
@@ -352,7 +353,8 @@ char* ZDCLogicalMapEntry::printLMapLine() {
   if (myzdcsec==0) mydet += "Unknown";
   else if (myzdcsec==1) mydet += "EM";
   else if (myzdcsec==2) mydet += "HAD";
-  else mydet += "LUM";
+  else if (myzdcsec==3) mydet += "LUM";
+  else mydet += "RPD";
 
   (hcaleid.htrTopBottom()==0) ? myfpga = "bot" : myfpga = "top";
 
diff --git a/Geometry/ForwardGeometry/interface/ZdcHardcodeGeometryLoader.h b/Geometry/ForwardGeometry/interface/ZdcHardcodeGeometryLoader.h
index 4ffdc39971ebd..c361c87f06ec7 100644
--- a/Geometry/ForwardGeometry/interface/ZdcHardcodeGeometryLoader.h
+++ b/Geometry/ForwardGeometry/interface/ZdcHardcodeGeometryLoader.h
@@ -43,6 +43,9 @@ class ZdcHardcodeGeometryLoader {
   float theHADSectiondX;
   float theHADSectiondY;
   float theHADSectiondZ;
+  float theRPDSectiondX;
+  float theRPDSectiondY;
+  float theRPDSectiondZ;
   
 };
 
diff --git a/Geometry/ForwardGeometry/src/ZdcHardcodeGeometryData.h b/Geometry/ForwardGeometry/src/ZdcHardcodeGeometryData.h
index aa4a56852ef53..fc0f3e2ebfd20 100644
--- a/Geometry/ForwardGeometry/src/ZdcHardcodeGeometryData.h
+++ b/Geometry/ForwardGeometry/src/ZdcHardcodeGeometryData.h
@@ -25,12 +25,15 @@ static const double X0 = 0.;
 static const double Z0 = 140000.0;
 static const double Y0 = 0.;
 static const double YLUM = 253.6;  
+static const double YRPD = 253.6;  
 static const double dYPlate = 62.5;
 static const double dYLUM = 320.0;
+static const double dYRPD = 320.0;
 static const double dXPlate = 48.0;
 static const double tiltangle = 0.7854; // 45 degrees 
 static const double theZSectionBoundaries[] = {-500.0,-395.55,-290.0};
 static const double theXChannelBoundaries[] = {-48.0,-28.8,-9.6,9.6,28.8};
 static const double theZLUMChannelBoundaries[] = {-395.55,-346.525,-301.5};
+static const double theZRPDChannelBoundaries[] = {-395.55,-346.525,-301.5};
 static const double theZHadChannelBoundaries[] = {-257.4,-118.2,21.0,160.2,};
 #endif
diff --git a/Geometry/ForwardGeometry/src/ZdcHardcodeGeometryLoader.cc b/Geometry/ForwardGeometry/src/ZdcHardcodeGeometryLoader.cc
index c35b208adb623..412ef3a7a4332 100644
--- a/Geometry/ForwardGeometry/src/ZdcHardcodeGeometryLoader.cc
+++ b/Geometry/ForwardGeometry/src/ZdcHardcodeGeometryLoader.cc
@@ -34,6 +34,7 @@ ZdcHardcodeGeometryLoader::load(DetId::Detector /*det*/, int subdet)
       fill(HcalZDCDetId::EM  ,hg );
       fill(HcalZDCDetId::LUM ,hg );
       fill(HcalZDCDetId::HAD ,hg );
+      fill(HcalZDCDetId::RPD ,hg );
    }
    return hg;
 }
@@ -45,6 +46,7 @@ ZdcHardcodeGeometryLoader::load()
    fill(HcalZDCDetId::EM  ,hg );
    fill(HcalZDCDetId::LUM ,hg );
    fill(HcalZDCDetId::HAD ,hg );
+   fill(HcalZDCDetId::RPD ,hg );
    return hg;
 }
 
@@ -97,6 +99,7 @@ ZdcHardcodeGeometryLoader::makeCell(const HcalZDCDetId& detId,
 
    static const double angEM  ( 0 ) ; // the angles of front face wrt vertical
    static const double angLUM ( 0 ) ;
+   static const double angRPD ( 0 ) ;
    static const double angHAD ( atan( 1. ) ) ; // this is 45 deg
 
    // these dimensions are **half**-sizes
@@ -104,14 +107,17 @@ ZdcHardcodeGeometryLoader::makeCell(const HcalZDCDetId& detId,
    static const double dxHAD ( 4.8 ) ;
    static const double dxEM  ( dxHAD/5. ) ;
    static const double dxLUM ( 4.8 ) ; // to be updated when known
+   static const double dxRPD ( 4.8 ) ; // to be updated when known
 
    static const double dhEM  ( 6.25 ) ;
    static const double dhLUM ( 6.25 ) ; // to be updated when known
    static const double dhHAD ( 6.25 ) ;
+   static const double dhRPD ( 6.25 ) ; // to be updated when known
 
    static const double dzEM  ( 33.*0.15 ) ;
    static const double dzLUM ( 23.5 ) ; // to be updated when known
    static const double dzHAD ( 0.82*6./cos(angHAD) ) ;
+   static const double dzRPD ( 23.5 ) ; // to be updated when known
 
    // these are not half-dimensions, they are offsets from nominal
    // for the center-of-front-face points
@@ -119,52 +125,55 @@ ZdcHardcodeGeometryLoader::makeCell(const HcalZDCDetId& detId,
    static const double xOffEM  ( -4.*dxEM ) ; 
    static const double xOffLUM ( 0 ) ; 
    static const double xOffHAD ( 0 ) ; 
+   static const double xOffRPD ( 0 ) ; 
 
    static const double yOffEM  ( 0 ) ; 
    static const double yOffLUM ( 0 ) ; 
    static const double yOffHAD ( 0 ) ; 
+   static const double yOffRPD ( 0 ) ; 
 
    static const double zOffEM  ( -49.85  - 0.15 ) ; 
    static const double zOffLUM ( -39.555        ) ; 
    static const double zOffHAD ( -29.00         ) ; 
+   static const double zOffRPD ( -39.555        ) ; 
 
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
    double dx, dh, dz, x, y, z, an ;
 
-   if( section==HcalZDCDetId::EM )
-   {
-      dx = dxEM ;
-      dh = dhEM ;
-      dz = dzEM ;
-      an = angEM ;
-      x  = zside*( x0 + xOffEM + ( channel - 1.0 )*dxEM*2. ) ;
-      y  = y0 + yOffEM ;
-      z  = zside*( z0 + zOffEM ) ;
-   }
-   else
-   {
-      if( section==HcalZDCDetId::LUM )
-      {
-	 dx = dxLUM ;
-	 dh = dhLUM ;
-	 dz = dzLUM ;
-	 an = angLUM ;
-	 x  = zside*( x0 + xOffLUM ) ;
-	 y  = y0 + yOffLUM ;
-	 z  = zside*( z0 + zOffLUM + ( channel - 1.0 )*dzLUM*2. ) ;
-      }
-      else
-      {
-	 assert( section==HcalZDCDetId::HAD ) ;
-	 dx = dxHAD ;
-	 dh = dhHAD ;
-	 dz = dzHAD ;
-	 an = angHAD ;
-	 x  = zside*( x0 + xOffHAD ) ;
-	 y  = y0 + yOffHAD ;
-	 z  = zside*( z0 + zOffHAD + ( channel - 1.0 )*dzHAD*2. ) ;
-      }
+   if( section==HcalZDCDetId::EM ) {
+     dx = dxEM ;
+     dh = dhEM ;
+     dz = dzEM ;
+     an = angEM ;
+     x  = zside*( x0 + xOffEM + ( channel - 1.0 )*dxEM*2. ) ;
+     y  = y0 + yOffEM ;
+     z  = zside*( z0 + zOffEM ) ;
+   } else if( section==HcalZDCDetId::LUM ) {
+     dx = dxLUM ;
+     dh = dhLUM ;
+     dz = dzLUM ;
+     an = angLUM ;
+     x  = zside*( x0 + xOffLUM ) ;
+     y  = y0 + yOffLUM ;
+     z  = zside*( z0 + zOffLUM + ( channel - 1.0 )*dzLUM*2. ) ;
+   } else if( section==HcalZDCDetId::RPD ) {
+     dx = dxRPD ;
+     dh = dhRPD ;
+     dz = dzRPD ;
+     an = angRPD ;
+     x  = zside*( x0 + xOffRPD ) ;
+     y  = y0 + yOffRPD ;
+     z  = zside*( z0 + zOffRPD + ( channel - 1.0 )*dzRPD*2. ) ;
+   } else {
+     assert( section==HcalZDCDetId::HAD ) ;
+     dx = dxHAD ;
+     dh = dhHAD ;
+     dz = dzHAD ;
+     an = angHAD ;
+     x  = zside*( x0 + xOffHAD ) ;
+     y  = y0 + yOffHAD ;
+     z  = zside*( z0 + zOffHAD + ( channel - 1.0 )*dzHAD*2. ) ;
    }
 
    const GlobalPoint fc ( x, y, z );