The OCLS:

;-----------------------------------------------------------------------------
;-----------------------------------------------------------------------------
ObjectCreationList SUPERWEAPON_GLAArtilleryBarrage1
  DeliverPayload
    Transport                       = ChinaArtilleryCannon
    FormationSize                   = 12
    FormationSpacing                = 1.0
    StartAtPreferredHeight          = Yes
    StartAtMaxSpeed                 = Yes
    MaxAttempts                     = 1                   ;max attempts
    DeliveryDistance                = 0                 ;distance from target allowed to start/stop dropping.
    WeaponErrorRadius               = 300                ; how bad the artillerist is
    DelayDeliveryMax                = 3000                ; his delayed reaction to "Fire!"
    VisibleItemsDroppedPerInterval  = 1                   ;Drops two bombs at a time
    VisibleDropBoneBaseName         = RootTransform       ;The bombs are created and dropped at this bone base
    VisibleSubObjectBaseName        = Bomb                ;The bombs are visible until dropped.
    VisibleNumBones                 = 1                   ;Number of bones.
    VisiblePayloadTemplateName      = SpectreHowitzerShell  ;Created when payload is dropped.
    VisiblePayloadWeaponTemplate    = ArtilleryBarrageDamageWeapon
    InheritTransportVelocity        = Yes                 ;The bombs will start at transport velocity.
    ExitPitchRate                   = 90                 ;The bomb will pitch down.
    SelfDestructObject              = Yes                 ; so the delivery vehicle goes away 'POP!'
    DeliveryDecalRadius = 125
    DeliveryDecal
      Texture           = SCCArtilleryBarrage_China
      Style             = SHADOW_ALPHA_DECAL
      OpacityMin        = 25%
      OpacityMax        = 50%
      OpacityThrobTime  = 500
      Color             = R:255 G:156 B:0 A:255
      OnlyVisibleToOwningPlayer = Yes
    End
  End
End


;-----------------------------------------------------------------------------
;-----------------------------------------------------------------------------
ObjectCreationList SUPERWEAPON_GLAArtilleryBarrage2
  DeliverPayload
    Transport                       = ChinaArtilleryCannon
    FormationSize                   = 24
    FormationSpacing                = 1.0
    StartAtPreferredHeight          = Yes
    StartAtMaxSpeed                 = Yes
    MaxAttempts                     = 1                   ;max attempts
    DeliveryDistance                = 0                 ;distance from target allowed to start/stop dropping.
    WeaponErrorRadius               = 300                 ; how bad the artillerist is
    DelayDeliveryMax                = 3000                ; his delayed reaction to "Fire!"
    VisibleItemsDroppedPerInterval  = 1                   ;Drops two bombs at a time
    VisibleDropBoneBaseName         = RootTransform       ;The bombs are created and dropped at this bone base
    VisibleSubObjectBaseName        = Bomb                ;The bombs are visible until dropped.
    VisibleNumBones                 = 1                   ;Number of bones.
    VisiblePayloadTemplateName      = SpectreHowitzerShell  ;Created when payload is dropped.
    VisiblePayloadWeaponTemplate    = ArtilleryBarrageDamageWeapon
    InheritTransportVelocity        = Yes                 ;The bombs will start at transport velocity.
    ExitPitchRate                   = 90                ;The bomb will pitch down.
    SelfDestructObject              = Yes                 ; so the delivery vehicle goes away 'POP!'
    DeliveryDecalRadius = 125
    DeliveryDecal
      Texture           = SCCArtilleryBarrage_China
      Style             = SHADOW_ALPHA_DECAL
      OpacityMin        = 25%
      OpacityMax        = 50%
      OpacityThrobTime  = 500
      Color             = R:255 G:156 B:0 A:255
      OnlyVisibleToOwningPlayer = Yes
    End
  End
End


;-----------------------------------------------------------------------------
;-----------------------------------------------------------------------------
ObjectCreationList SUPERWEAPON_GLAArtilleryBarrage3
  DeliverPayload
    Transport                       = ChinaArtilleryCannon
    FormationSize                   = 36
    FormationSpacing                = 1.0
    StartAtPreferredHeight          = Yes
    StartAtMaxSpeed                 = Yes
    MaxAttempts                     = 1                  ;max attempts
    DeliveryDistance                = 0                 ;distance from target allowed to start/stop dropping.
    WeaponErrorRadius               = 300                 ; how bad the artillerist is
    DelayDeliveryMax                = 3000                ; his delayed reaction to "Fire!"
    VisibleItemsDroppedPerInterval  = 1                   ;Drops two bombs at a time
    VisibleDropBoneBaseName         = RootTransform       ;The bombs are created and dropped at this bone base
    VisibleSubObjectBaseName        = Bomb                ;The bombs are visible until dropped.
    VisibleNumBones                 = 1                   ;Number of bones.
    VisiblePayloadTemplateName      = SpectreHowitzerShell  ;Created when payload is dropped.
    VisiblePayloadWeaponTemplate    = ArtilleryBarrageDamageWeapon
    InheritTransportVelocity        = Yes                 ;The bombs will start at transport velocity.
    ExitPitchRate                   = 90                  ;The bomb will pitch down.
    SelfDestructObject              = Yes                 ; so the delivery vehicle goes away 'POP!'
    DeliveryDecalRadius = 300
    DeliveryDecal
      Texture           = SCCArtilleryBarrage_China
      Style             = SHADOW_ALPHA_DECAL
      OpacityMin        = 25%
      OpacityMax        = 50%
      OpacityThrobTime  = 500
      Color             = R:255 G:156 B:0 A:255
      OnlyVisibleToOwningPlayer = Yes
    End
  End
End


The sciences:

Science SCIENCE_GLAArtilleryBarrage1
  PrerequisiteSciences = SCIENCE_AMERICA SCIENCE_Rank3
  SciencePurchasePointCost = 1
  IsGrantable = Yes
  DisplayName = SCIENCE:ChinaArtilleryBarrage
  Description = CONTROLBAR:ToolTipChinaScienceArtilleryBarrage
End

Science SCIENCE_GLAArtilleryBarrage2
  PrerequisiteSciences = SCIENCE_GLAArtilleryBarrage1 SCIENCE_Rank3
  SciencePurchasePointCost = 1
  IsGrantable = Yes
  DisplayName = SCIENCE:ChinaArtilleryBarrage2
  Description = CONTROLBAR:ToolTipChinaScienceArtilleryBarrage
End

Science SCIENCE_GLAArtilleryBarrage3
  PrerequisiteSciences = SCIENCE_GLAArtilleryBarrage2 SCIENCE_Rank3
  SciencePurchasePointCost = 1
  IsGrantable = Yes
  DisplayName = SCIENCE:ChinaArtilleryBarrage3
  Description = CONTROLBAR:ToolTipChinaScienceArtilleryBarrage
End

The buttons:

CommandButton Command_PurchaseScienceGLAArtilleryBarrage1
  Command           = PURCHASE_SCIENCE
  Science           = SCIENCE_GLAArtilleryBarrage1
  ButtonImage       = SSBarrage
  ButtonBorderType  = UPGRADE ; Identifier for the User as to what kind of button this is
End

CommandButton Command_PurchaseScienceGLAArtilleryBarrage2
  Command           = PURCHASE_SCIENCE
  Science           = SCIENCE_GLAArtilleryBarrage2
  ButtonImage       = SSBarrage2
  ButtonBorderType  = UPGRADE ; Identifier for the User as to what kind of button this is
End

CommandButton Command_PurchaseScienceGLAArtilleryBarrage3
  Command           = PURCHASE_SCIENCE
  Science           = SCIENCE_GLAArtilleryBarrage3
  ButtonImage       = SSBarrage3
  ButtonBorderType  = UPGRADE ; Identifier for the User as to what kind of button this is
End


CommandButton Command_GLAArtilleryBarrage
  Command           = SPECIAL_POWER
  SpecialPower      = SuperweaponGLAArtilleryBarrage
  Options           = NEED_SPECIAL_POWER_SCIENCE NEED_TARGET_POS CONTEXTMODE_COMMAND
  Science           = SCIENCE_GLAArtilleryBarrage1 SCIENCE_GLAArtilleryBarrage2 SCIENCE_GLAArtilleryBarrage3
  TextLabel         = CONTROLBAR:ArtilleryBarrage
  ButtonImage       = SSBarrage
  ButtonBorderType  = ACTION ; Identifier for the User as to what kind of button this is
  DescriptLabel     = CONTROLBAR:TooltipFireArtilleryBarrage
  RadiusCursorType  = ARTILLERYBARRAGE
  InvalidCursorName     = GenericInvalid
End


CommandButton Command_GLAArtilleryBarrageFromShortcut
  Command           = SPECIAL_POWER_FROM_SHORTCUT
  SpecialPower      = SuperweaponGLAArtilleryBarrage
  Options           = CONTEXTMODE_COMMAND
  Science           = SCIENCE_GLAArtilleryBarrage1 SCIENCE_GLAArtilleryBarrage2 SCIENCE_GLAArtilleryBarrage3
  TextLabel         = CONTROLBAR:NoHotKeyArtilleryBarrage
  ButtonImage       = SSBarrage
  DescriptLabel     = CONTROLBAR:TooltipFireArtilleryBarrage
  RadiusCursorType  = ARTILLERYBARRAGE
  InvalidCursorName     = GenericInvalid
End

Superweapon command sets:

CommandSet SupW_SCIENCE_AMERICA_CommandSetRank3
   1 = Command_PurchaseSciencePathfinder
   3 = Early_Command_PurchaseScienceLeafletDrop
   4 = Command_PurchaseScienceParadrop1
   5 = Command_PurchaseScienceParadrop2
   6 = Command_PurchaseScienceParadrop3
   7 = Command_PurchaseScienceA10ThunderboltMissileStrike1
   8 = Command_PurchaseScienceA10ThunderboltMissileStrike2
   9 = Command_PurchaseScienceA10ThunderboltMissileStrike3
  10 = Command_PurchaseScienceGLAArtilleryBarrage1
  11 = Command_PurchaseScienceGLAArtilleryBarrage2
  12 = Command_PurchaseScienceGLAArtilleryBarrage3
  14 = Command_PurchaseScienceSpectreGunship1
  15 = Command_PurchaseScienceSpectreGunship2
END

CommandSet SupW_AmericaCommandCenterCommandSet
  1  = SupW_Command_ConstructAmericaDozer
  2  = AirF_Command_SpectreGunship
  4  = Early_Command_LeafletDrop
  5  = Command_A10ThunderboltMissileStrike
  6  = Command_Paradrop
  7  = Command_SpyDrone
  8  = Command_GLAArtilleryBarrage
  9  = Command_DaisyCutter
 10  = Command_SpySatelliteScan
 13  = Command_SetRallyPoint
 14  = Command_Sell
End

Command center module:

  Behavior           = OCLSpecialPower ModuleTag_GLAArtilleryBarrage
    SpecialPowerTemplate = SuperweaponGLAArtilleryBarrage
    UpgradeOCL           = SCIENCE_GLAArtilleryBarrage3 SUPERWEAPON_GLAArtilleryBarrage3
    UpgradeOCL           = SCIENCE_GLAArtilleryBarrage2 SUPERWEAPON_GLAArtilleryBarrage2
    OCL                  = SUPERWEAPON_GLAArtilleryBarrage1
    CreateLocation       = CREATE_AT_LOCATION
  End