The beam frame ISO tank mounts the cylinder in an open beam frame rather than a full-collar frame, saving 200 to 400 kg of tare and modestly improving payload economics. Beam-frame designs are common on offshore equipment (where the lifting frame is structurally optimised for crane handling) and on some mainstream chemical fleets where the operator has decided the additional structural protection of a full-collar frame is not worth the tare penalty for their cargo profile.
What beam frame is built for
Beam frame variants serve standard chemical T11 cargoes where the operator has chosen weight optimisation over additional crash protection. The cylinder still sits inside an ISO 1CC frame footprint with corner castings at the four upper and four lower corners, but the side framing is reduced to longitudinal beams rather than full sheet panels.
Construction and materials
316L stainless cylinder identical to a full-collar T11. The frame uses longitudinal Cor-Ten or Q345D/E36 weathering-steel beams between the corner castings, with diagonal bracing for stiffness and the standard top and bottom corner-casting interfaces (ISO 1161). The cylinder is exposed on the sides rather than concealed behind sheet panels. Tare drops to 3,500 to 3,900 kg from the typical 4,000 kg of a full-collar T11.
When beam frame is the right choice
Beam frame is the right tank for operators with established cargo profiles where the cylinder doesn’t need full sheet protection (relatively gentle handling, contained route history). The 200 to 400 kg of tare savings translates into 200 to 400 kg of additional payload, which is meaningful on dense-cargo routes where the weight cap binds before the volume cap.
When beam frame is the wrong choice
Beam frame is the wrong tank for routes with rough handling (some Asian inland routes, certain transhipment operations) where the cylinder benefits from full-collar protection. It is also the wrong tank for operators whose maintenance economics work better with the standardised full-collar frame; mixing beam-frame and full-collar tanks in one fleet adds operational complexity.
How a beam frame booking is verified
Pre-loading inspection covers the standard plate stack and the cylinder-condition check (more visible on a beam-frame tank because the cylinder is exposed). Operator history confirms route profiles that suit the lighter frame.