function digColumn()
	while turtle.dig() do end
	while not turtle.forward() do end
	while turtle.digUp() do end
	while turtle.digDown() do end
end

function digTunnelPart()
	digColumn()
	turtle.turnRight()
	digColumn()
	turtle.back()
	for i = 1, 2 do
		turtle.turnLeft()
	end
	digColumn()
end

function digTunnelSection()
	for i = 1, 4 do
		digTunnelPart()
		turtle.back()
		turtle.turnRight()
	end
	turtle.select(16)
	turtle.placeDown()
	turtle.turnRight()
	for i = 1, 11 do
		digTunnelPart()
		turtle.back()
		turtle.turnRight()
	end
	turtle.select(16)
	turtle.placeDown()
	for i = 1, 11 do
		turtle.back()
	end
	for i = 1, 2 do
		turtle.turnLeft()
	end
	for i = 1, 11 do
		digTunnelPart()
		turtle.back()
		turtle.turnRight()
	end
	turtle.select(16)
	turtle.placeDown()
	for i = 1, 11 do
		turtle.back()
	end
	turtle.turnRight()
	digTunnelPart()
end

digTunnelSection()