anchor.diff:           
         END DO !J = 1,p%BldNodes ! Loop through the blade nodes / elements
      END DO !K = 1,p%NumBl
  -   
  -   ! tower nodes
  -   DO J=1,u_AD%TowerMotion%nnodes
  -      Node = Node + 1
  -      OpFM%u%pxVel(Node) = u_AD%TowerMotion%TranslationDisp(1,J) + u_AD%TowerMotion%Position(1,J)
  -      OpFM%u%pyVel(Node) = u_AD%TowerMotion%TranslationDisp(2,J) + u_AD%TowerMotion%Position(2,J)
  -      OpFM%u%pzVel(Node) = u_AD%TowerMotion%TranslationDisp(3,J) + u_AD%TowerMotion%Position(3,J)
  -   END DO
  -   
  -   
  +
  +   if (OpFM%p%NMappings .gt. OpFM%p%NumBl) then
  +      ! tower nodes
  +      DO J=1,u_AD%TowerMotion%nnodes
  +         Node = Node + 1
  +         OpFM%u%pxVel(Node) = u_AD%TowerMotion%TranslationDisp(1,J) + u_AD%TowerMotion%Position(1,J)
  +         OpFM%u%pyVel(Node) = u_AD%TowerMotion%TranslationDisp(2,J) + u_AD%TowerMotion%Position(2,J)
  +         OpFM%u%pzVel(Node) = u_AD%TowerMotion%TranslationDisp(3,J) + u_AD%TowerMotion%Position(3,J)
  +      END DO
  +   end if
  +
      ! Do the Actuator Force nodes now
      Node = 1   ! displaced hub position 
      OpFM%u%pxForce(Node) = OpFM%u%pxVel(Node)
  
positive.code:    !.......................
  
     ! mesh mapping from line2 mesh to point mesh
     k = SIZE(u_AD%BladeMotion) + 1
     
  #ifdef DEBUG_OPENFOAM   
     DO J = 1,u_AD%TowerMotion%NNodes
        write(aerodynForcesFile,*) u_AD%TowerMotion%TranslationDisp(1,j) + u_AD%TowerMotion%Position(1,j), ', ', u_AD%TowerMotion%TranslationDisp(2,j) + u_AD%TowerMotion%Position(2,j), ', ', u_AD%TowerMotion%TranslationDisp(3,j) + u_AD%TowerMotion%Position(3,j), ', ', OpFM%y%u(1 + OpFM%p%NumBl*u_AD%BladeMotion(k)%NNodes + j), ', ', OpFM%y%v(1 + OpFM%p%NumBl*u_AD%BladeMotion(k)%NNodes + j), ', ', OpFM%y%w(1 + OpFM%p%NumBl*u_AD%BladeMotion(k)%NNodes + j), ', ', y_AD%TowerLoad%Force(1,j), ', ', y_AD%TowerLoad%Force(2,j), ', ', y_AD%TowerLoad%Force(2,j)
     END DO
  
negative.code:       ! number of force nodes in the interface
     Opfm%p%NnodesForceBlade =  InitInp%NumActForcePtsBlade 
     OpFM%p%NnodesForceTower = InitInp%NumActForcePtsTower
     OpFM%p%NnodesForce = 1 + OpFM%p%NumBl * InitInp%NumActForcePtsBlade
     OpFM%p%BladeLength = InitInp%BladeLength
  
     if ( y_AD%TowerLoad%NNodes > 0 ) then
        OpFM%p%NMappings = OpFM%p%NumBl + 1
        OpFM%p%TowerHeight = InitInp%TowerHeight
        OpFM%p%NnodesForce = OpFM%p%NnodesForce + InitInp%NumActForcePtsTower
     else
        OpFM%p%NMappings = OpFM%p%NumBl
     end if
  
        ! air density, required for normalizing values sent to OpenFOAM:
     OpFM%p%AirDens = AirDens
  