Checklists for leakproofness

Filling and discharging of rail tank-wagons for liquids

29. December 2011 | Leitfaden

Long version of this document

Four standardised checklists help to avoid leaks from tank-wagons for liquids which mostly occur by incorrect filling or discharging processes.

The filler and unloader are the undertakings that fill dangerous goods into tanks (e.g. tank-wagons) or discharge (unload) them. The legal obligations of these legal entities include
  • checking that closing devices are leakproof once the tank has been filled (“filler”, see RID [= Regulations concerning the International Carriage of Dangerous Goods by Rail]), and
  • ensuring after the tank has been unloaded that the valves and inspection openings are closed (“unloader”, see RID
Depending on the product and specification of the tank and fittings, tank-wagons may:
  • be filled from the bottom through the bottom valve in conjunction with the external shut-off device (discharge valve, dry coupling) or filled from the top through the filling pipe or dome cover;
  • discharged through the bottom shut-off device (discharge valve, dry coupling) or from the top through an attached dip tube.
Checklists Four checklists have been developed:
  • top filling
  • top discharge
  • bottom filling
  • bottom discharge
They are a chronological sequence of the steps necessary for the filling and discharge of tank-wagons. Using them as an aid, users can be sure that they have followed them fully in the correct sequence. If one of the steps cannot be carried out properly, the filling or discharge process is interrupted or stopped until the discrepancy/fault is rectified. This should enable errors and unsafe situations to be recognised in advance and avoided.

As the most frequent cause of leaks is incorrect filling or discharge processes, the main aim behind these standardised checklists is to avoid leaks from tank-wagons for liquids by means of correct and professional handling on the part of operating staff working for fillers and unloaders (note: tank-wagons for pressurised gases are not dealt with here). They include the necessary steps (checkpoints) in the procedure to ensure leakproofness in the appropriate sequence which normally have to be observed when filling or emptying liquids into or from tank-wagons. They may need to be supplemented by the user for other specific operational steps/procedures (operating instructions).

The translation of the original German version into English has been made by the Intergovernmental Organisation for International Carriage by Rail (OTIF)

The four checklists are integrated into the so-called "Langfassung" (full version of this document) in the download sector at the top of this page.


For questions or suggestions, please feel free to contact us.

 Jörg Roth

Contact person

Dipl.-Ing. Jörg Roth

Verkehr und Logistik, Transportsicherheit, Gefahrgut, TUIS