Torque Box 2 : A structural component placed between the turntable and the chassis or part of the chassis frame of an aerial device to absorb the stresses of operation
NFPA 1911 Standard for the Inspection, Maintenance, Testing, and Retirement of In-Service Automotive Fire Apparatus, 2007 ed. https://www.iafc.org/files/1EVM/evms_NFPA1911_1071 andEVT.pdf, (Std: Insp, Maint, Tst and Retirement of In-Srvc Automotive Fr Aptus - Amer) {415 NFC}