underframe in French
Each body section to be tested shall be firmly and securely attached to the test bench through a rigid underframe structure in such a way that,
For the purposes of the test, bodywork sections shall have sections of the normal structure fitted between the pillars in relation to the floor, underframe, sides and roof.
For lifting by jacks (limited to the "connections" at the maximum), each wagon shall be fitted with four base plates, two under each underframe sole-bar, placed symmetrically in relation to the transverse axis of the wagon.
the internal supporting structure that gives an artifact its shape: building, skeleton, frame, edifice, aircraft, chassis, skeletal frame, ship, hoop, supporting structure