Best Vertical Takeup Design For Belt Conveyors

If a "dutchman" was not provided, you may need to add an underside take-up to your conveyor.How to get more belt take-up.There is more belt stretch on a long, long conveyor than the regular take-up and dutchman will give.So an "underside take-up" should also be used.When should i use underside take-up? on conveyors 60' long, or longer.