Minecraft: Tunnel Digger Using One Cmd Block

/summon MinecartCommandBlock ~1 ~1 ~ {Riding:{id:"MinecartCommandBlock",Command:"/setblock ~1 ~-1 ~ 157 0 replace",Riding:{id:"MinecartCommandBlock",Command:"/setblock ~-2 ~-1 ~ 0 0 replace",Riding:{id:"MinecartCommandBlock",Command:"/setblock ~-3 ~-2 ~ 0 0 replace",Riding:{id:"MinecartCommandBlock",Command:"/setblock ~-2 ~-1 ~1 0 0 replace",Riding:{id:"MinecartCommandBlock",Command:"/setblock ~-2 ~-2 ~1 0 0 replace",Riding:{id:"MinecartCommandBlock",Command:"/setblock ~2 ~-2 ~ 152 0 replace",Riding:{id:"FallingSand",Time:1,TileID:157,Riding:{id:"FallingSand",Time:1,TileID:152}}}}}}}},Command:"/setblock ~1 ~-2 ~ 152 0 replace"}