stripmine

function mineStep()
    turtle.dig()
    turtle.forward()
    turtle.digUp()
    end

function excavation(tunnels, tLength)
    for i = 1, tunnels do
        for n = 1, tLength do
            mineStep()
            end
        turtle.turnRight()
        turtle.turnRight()
        for n = 1, tLength do
            turtle.forward()
            end
        turtle.dig()
        turtle.up()
        turtle.dig()
        turtle.down()
        turtle.select(16)
        turtle.place()
        for l = 1, 15 do
            turtle.select(l)
            turtle.drop()
            end
        turtle.turnLeft()
        mineStep()
        mineStep()
        mineStep()
        turtle.turnLeft()
        end
    end

--first parameter is the number of tunnels, second is the length of a tunnel
--put a number of chests corresponding to the number of tunnels into the turtles last (bottom right) slot
excavation(1,5)