While a time chartered ro-ro freight, ferry is loading cargo, her hydraulics fail making the stern ramp unusable. What provisions in the charter party will usually cover this and other failures of ship’s equipment?

The standard (printed) charter party clauses will usually include a Suspension of Hire Clause that provides for hire to cease after the vessel has been unavailable to charterers for a specified period of time, e. g. 24 hours, because of machinery breakdown, winch breakdowns, crew strikes, hull damage, drydocking or other reasons within owners’ control. 

However, a rider clause will probably be appended to the standard charter party document, reducing the time allowed for repairs, in the case of a ro-ro ferry to perhaps an hour or 30 minutes. (A rider clause overrides a standard clause that conflicts with it. )