Rail-specific operating requirements: wagon construction and inspection, loading, unloading, marshalling and prohibitions
The wagon itself
RID Part 6 covers construction and testing, with Chapter 6.8 for tanks and their fittings and the remaining chapters for other wagons and equipment. A wagon must be suitable for the load: floor and roof sound, doors closing, no incompatible residues from the previous load, tank plate in date, and the fittings protected against damage in normal traffic. In the EU the wagon also needs an entity in charge of maintenance, and its maintenance history belongs to the railway undertaking's safety management system, not to the consignor.
Loading and unloading
Loading, unloading and handling are governed by Chapter 7.5.1: only instructed persons may load, no smoking or ignition sources, the wagon is checked for cleanliness and suitability before loading, the load is distributed and secured so it cannot shift or fall out, and axle and loading limits are respected. On unloading, residues are removed, closures are secured and the wagon is either cleaned or left marked as empty/uncleaned before it moves.
Marshalling and train composition
Dangerous goods wagons must be placed and shunted so as to limit the consequences of an incident: restrictions on hump or loose shunting for loads sensitive to shock, separation from the locomotive and from vehicles not carrying dangerous goods where the rules require it, and observance of the mixed loading prohibitions at wagon level. Marshalling yards are where most rail dangerous goods incidents begin.
Prohibitions
Dangerous goods are not carried in passenger trains; tank-wagons are not used with expired inspections; leaking or damaged packages are not forwarded; loading is stopped where the weather or the wagon makes it unsafe.
Worked example
A loader finds a hole in the wagon floor. Extra dunnage will not fix it: the wagon is unsuitable, the packaging could be damaged from below, and the correct action is to reject the wagon and request another. Recording the rejection protects both the loader and the carrier.
Traps
Treating tank inspection as a carrier formality; forgetting the unloading residual duty; assuming marshalling restrictions are only advisory; ignoring load distribution rules.