The 3D beam elements represent critical master sections of the BIW responsible for achieving structural adequacy. Each 3D beam is then broken down in toMaster Section.ppt - Free download as Powerpoint Presentation (.ppt), PDF File (.pdf), Text File (.txt) or view presentation slides online. LX BIW Engineering Department. DaimlerChrysler What Defines a “Great BIW Design” Roof Bow. 3 Layer Body Side. Sections. Constant Moment B-Pillar. BIW parts consist of Cover, Body, Floor and Encon. Cover is a Below figure is the master sketch provided for design of inner panel of Hood.