Complex sentence: Provision is made at one end of each carriage for one wheelchair and occupant to be carried, when this space is not needed able-bodied passengers may make use of the three wall-mounted fold-down seats.
Split into simpler sentences: Provision is made at one end of each carriage for one wheelchair and occupant. When this space is not needed able-bodied passengers may make use of the three wall-mounted fold-down seats.