An improved attachment for positioning a rotary waterwall combustor within a tire so it rotational axis is fixed and the rotary waterwall combustor, the tire and the attachment linkage are free to expand independently without inducing stresses due to differential thermal expansion; the attachment linkage comprises a plurality of support blocks attached to the rotary waterwall combustor and a plurality of support lugs attached to the tire with a plurality of links pivotally connected to the blocks and lugs with an elongated opening cooperatively associated with one of the pivotal connections to allow pivotal and axial movement and eliminate stresses caused by differential thermal expansion.