3. The role of free warehousing space in preserving the resiliency of the ports cannot be overstressed. If congestion occurs on the railways or at works, it will at once block the flow of imports out of the ports, and may in due course arrest the discharge of cargoes. The shock of intermittent congestion can readily be taken, however, if a substantial margin of unused warehouse accommodation is normally maintained. In this connection it would appear that at Avonmouth there is no large reserve of storage space other than transit sheds, which are however of considerable extent.