conduction sleeve plenum 137 and through the structural sub frame 128 129 such as through sub frame conduction transfer plenum 144 to the various electrical components of the expandable structure of the present invention power may be delivered from the upper and lower integral insulated conduction sleeves 134 135 to the structural sub frame conduction transfer plenum 144 by an insulated caster carriage dongle 146 which may be internally affixed to the lower nested structural sub frame 129 as shown in fig7 c the insulated caster carriage dongle 146 may be adapted to travel within a track of conduction sleeve 135 in one aspect the insulated caster carriage dongle 146 may include one or more rollers adapted for assisting in the translation of the dongle with respect to the conduction sleeve 135 and for maintaining electrical contact with the conduction sleeve 135 as lower nested structural sub frame 129 in conjunction with the fixed worm gear screw actuator 131 and reversible low geared helical motor and modified worm gear sleeve 132 is forced along the lower sub frame rail guide 109 the affixed insulated caster carriage dongle 146 maintains a constant closed circuit power connection by rolling along the inside of the electrified integral insulated conduction sleeve 135 this method of power transfer not only allows electrification of both sides of the two part shell structural frame and.