These joints were strengthened using pegs, dowels and leather or cord lashings. They join the wooden planks together with dowels and rattan. Connections are usually made with bolts or steel dowels and steel plates. Wood laminated by stress, glued, dowels, or nails lumber are good for panel bridges. They may be reinforced with dowels or mechanical fasteners to resist twisting of the wood. The framework is held together with metal dowels and pegs. The white oak floor is fitted together with wooden peg dowels. Homemade versions can be made from dowels, bamboo rods, or closet poles. The crossarm is fastened to the lower and upper shaft by two bronze dowels. The walls were made without any mortar and instead used iron dowels and brackets. Simple nunchaku may be easily constructed from wooden dowels and a short length of chain. These were "sewn" together with dowels and lashings. Modern excavations have uncovered a "massive palisade of teak beams held together with iron dowels". Additionally, it may be combined with the use of dowels, metal beams and pipes. The dowels and hoops are used to tighten the tension of the membrane.