Pierced Beam Design
Crossmembers pass through the beam web instead of sitting on top, allowing the deck to sit roughly 3–5 inches lower with a flush deck surface.
A heavy trailer is not automatically a better trailer. Southland uses engineered beam technology on select goosenecks, deckovers, and Renn Industrial Flatbeds to place strength where the load demands it. That helps reduce dead weight while protecting payload capacity.
Old-school frame building often means using bigger and heavier beams everywhere. That can make the trailer heavy before it is even loaded. Southland custom-fabricates beams so the frame is taller and stronger in high-stress zones and lighter where less steel is needed.
A good frame should work with the load, not fight it with random extra steel. Engineered beams act like a purpose-built spine for serious hauling.
The vertical web is shaped to match where the trailer frame sees the most bending force.
90 KSI steel helps carry heavy loads while keeping the frame weight under control.
The beam web and flanges are joined to create a unified frame rail for heavy service.
More steel is not always better. Every extra pound built into the frame is a pound you cannot use for payload. Engineered beams solve this by changing the beam shape to match the stress. The center area can be taller where bending is highest, while the ends can be lighter where the load is lower. When paired with a constant radius cambered deck, the trailer can flex under load and return to shape instead of staying bowed.
It is a custom-built frame beam shaped to put more steel in high-stress areas and less steel where it is not needed.
Legal road weight is limited. If the trailer weighs less empty, more of that legal limit can be used for payload.
KSI means thousands of pounds per square inch. A 90 KSI yield rating means the steel can withstand approximately 90,000 pounds per square inch before permanently deforming—roughly two to three times the yield strength of common mild steels.
This design is used on select Southland goosenecks, Southland deckovers, and Renn Industrial Flatbeds.