errrr...... don't you have any brains at all ? This has nothing to do with ropes but the theory that states that as investment in constant capital increases productivity (i.e. the margin of surplus labor relative to regular labor, and thus of surplus value relative to variable capital), it reduces the rate of profit (i.e. the ratio of surplus value relative to total capital). The capitalist then responds by investing more in raising productivity or expanding the scale of production, which in turn reduces profits per unit further after a while, and so on and so forth, in a vicious cycle of diminishing returns.