A boom for a pipelaying machine includes a pair of posts located in a first plane and disposed in a tapered configuration with respect to a second plane transverse to the first plane. The boom also includes a cross-brace disposed between the pair of posts and located partway along a length of the pair of posts. The cross-brace includes a first link member and a second link member disposed along the first plane. Further, each of the first and second link members are angularly offset from each other and the second plane respectively. Furthermore, ends of the first and second link members are rigidly attached to the pair of posts. The cross-brace further includes a first rib member and a second rib member disposed along the second plane and rigidly attached to the first link member and the second link member respectively.