"Failure to disconnect the product delivery hose(s) that connects the vehicle to a storage tank or utilisation point before moving a bulk delivery vehicle can lead to a serious incident.
A tow-away incident occurs when flexible hose(s) used to transfer product between a delivery vehicle and stationary equipment is not disconnected prior to moving the vehicle.
When this occurs, flexible hoses and the interconnecting piping can be damaged or fail. Moving the vehicle while delivery hose(s) are still connected to fixed equipment not only creates the potential for equipment damage but also can result in the creation of a hazardous atmosphere.
Personal injury can be caused due to a large quantity of gas or liquid under pressure being released by the ruptured hose(s) and the production of a potentially hazardous atmosphere (oxygen enriched or deficient) that can lead to cold burns, asphyxiation, fire or explosion. If the hose(s) resists the pulling effort and does not break, the vehicle can, in certain cases, pull away part or the whole of the fixed equipment or damage the delivery vehicle pipework.
Such incidents can also lead to disruption of service. The primary objective of this publication is to recommend practical methods for preventing road vehicles being moved away while still connected to fixed equipment.
It supports compliance with the relevant requirements of existing regulations and standards. This publication is also applicable to vehicles carrying cryogenic receptacles that are filled or emptied into a fixed installation while on board the vehicle.
Prevention of tow-away incidents of rail transportation is not covered by this publication. However, the principles discussed may be appropriate in some cases. The publication is intended for those who are involved in the specification, design and operation of bulk delivery vehicles.
The publication is part of the programme to develop Globally Harmonised publications amongst Regional Gas Associations."