Always have long bolts for tie down clips in place before raising or lowering sections to prevent rollers on opposite side from jacks from jumping the tracks. Always deflate seals before raising, lowering or closing sections. Use jacks in pairs, two on the same side at a time. In transit, tighten down all tie down clips. Release all tie down clips.
Open dust covers at A, drop area.
Deflate inflatable seals. Open all dust covers at roller axles. Install spreader bars and jack pads. Jack up Section B on one side, shift rollers and let side down with rollers bearing the load. Repeat on opposite side of B, remove spreader bars and move B to forward position.