A telescopic gate (sometimes 'overlapping sliding gate') uses two or more sliding panels that move in parallel and overlap when retracted. A 6 m opening with no runout space can be served by a two-section telescopic gate that retracts to 3 m. The runout requirement is roughly the opening width divided by the number of sections.
Telescopic gates are more mechanical than single-section sliders. Each section needs its own track or rollers, and an inter-section drive (cable, chain, or rack) synchronises movement so all sections start and stop together. Maintenance load goes up. Hardware cost is roughly 2x a comparable single-section slider.
CAD60 supports two- and three-section telescopic gates with automatically derived overlap, panel widths, and drive geometry.