Since the 1960’s diesel has been the predominant fuel used for the propulsion of heavy goods vehicles. Fuel-related requirements for dangerous goods (ADR) vehicles have been based upon this prevalence; however, duel fuel vehicles using CNG and LNG have raised issues concerning the use of such fuel systems on ADR vehicles. This paper discusses ADR vehicles and such gaseous fuels.
UN WP.15 (Carriage of Dangerous Goods) and ADR regulatory issues regarding CNG and LNG safety on ADR-regulated trucks
42. Mr. Seisler presented the problems associated with language in the ADR that says if the fuel leaks from the tank (on the vehicle) [it] should go to the ground, which is not necessarily the case with gaseous fuels (although LNG and LPG initially are heavier than air until they vaporize). He presents the results to date of the LNG TF discussions and the proposed language for an amendment.
Comments on the presentation:
43. If the text includes the phrase ‘above the auto ignition temperature of the fuel’ LNG dilution should be mentioned.
44. The language might include the flammability range of diesel and LNG, particularly if it is raised in the amendment.
45. Focusing on the word ‘leakage’ only without looking at the practical results that might not result in a fire.
46. Where are the ‘hot parts’ of the truck? Turbo charger; exhaust pipe; other engine components. But the chance of leakage near hot parts of the engine and the dispersion of LNG at that point suggests that the LNG is likely out of the flammability range. But there also could be a spark from an electrical component (i.e. in a garage).
47. A more scientific approach could/might be taken to study where the fuel goes and if it can come into contact with hot parts of the engine or hot parts of the load.
48. Mr. Piccolo knows someone who has some ADR expertise who might be able to assist with the amendment.