NOVELTY - The system (100) has a fuel cell stack (102) including a pair of ends and a compression plate (104) arranged adjacent to one of the ends of the fuel cell stack. Another compression plate (106) is arranged adjacent to the other end of the fuel cell stack. A U-shaped compression enclosure apparatus (110) has a unitary main body including a pair of fastening points (144) coupled to the former compression plate and an intermediate portion (150) placed adjacent to the latter compression plate. The compression enclosure apparatus is made of sheet metal.    USE - Fuel cell system for a vehicle i.e. electric vehicle.    ADVANTAGE - The system has the compression enclosure apparatus including the unitary main body that includes the fastening points coupled to the former compression plate and the intermediate portion placed adjacent to the latter compression plate, where the enclosure apparatus minimizes a number of components required to retain compression of the fuel cell stack, minimizes mass of the system and simplifies the design of the system. The system has an insulating layer for militating against heat loss from the fuel cell stack to an ambient environment in which the system is located. The insulating layer minimizes an amount of time in which the system is operated at a low output during startup procedure. The insulating layer arranged on an inner surface of the enclosure apparatus facilitates service of the system and militates the system against damage that occurs to the insulating layer arranged on an outer surface of the system. The system has a port for militating against removal of the system from the vehicle during servicing operation by providing service access for the fuel cell stack or a component arranged in an interior cavity of a pair of rigid structures, thus reducing service time and service cost of the system.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for assembling a fuel cell system.    DESCRIPTION OF DRAWING(S) - The drawing shows an exploded perspective view of a fuel cell system having a U-shaped compression enclosure apparatus.    Fuel cell system (100)    Fuel cell stack (102)    Compression plates (104, 106)    U-shaped compression enclosure apparatus (110)    Fastening points (144)    Intermediate portion (150)