Published: Sunday 30 September 2001


-- The cse panel of experts after completing their investigation concluded, "In an international perspective, we consider the safety level of the buses to be acceptable. However, there are still items or manufacturing operations that could be further improved in order to minimise the risk of unwanted incidents." Based on their suggestions, cse has written to the mrth proposed several changes in the notification:

All cng buses must undergo an inspection of the engine and high-pressure fuel storage system before being allowed on the road. Subsequently, this check should be carried out annually for safety compliance.

mrth must notify the technical and legal requirements for the authorisation of the conversion workshops. As of now, kit installation on vehicles be carried out by workshops authorised by the kit manufacturer/kit supplier. But the minimum requirements for these workshops, either legal or technical, have not been defined by the mrth . We can't allow any roadside mechanic to fit cng kits.

All converted/retrofitted buses must meet Euro II emissions standards and not the emissions standards meant for diesel and petrol vehicles in their year of manufacture to eliminate the possibility of bad conversion that can lead to both safety hazards and poor emissions. Euro IV standards should be notified for cng buses as soon as possible with the help of economic incentives for these vehicles.

Engine converters must obtain a new type approval for each separate diesel engine model they seek to retrofit. Current regulations allow extension of the type approval certificate to other engine/ cng -kit combinations than the one originally submitted for type approval. This can result in unacceptable exhaust emission levels. Since the number of diesel engine models used in Delhi buses is small -- just three models -- this would not pose much of a hurdle. Requirements for durability testing, emissions warranty and other commitments by the manufacturer of the engine should be laid down.

The capabilities and capacities of the type approval institutions should be improved in order to reduce the duration of the whole type approval procedure to reasonable, internationally acceptable timeframe. At the moment it is inordinately long.

In the production of the chassis for cng buses, there is still some room for improvement in areas such as the material of the high-pressure piping, fixing of pipes to the chassis, tightening of the couplings, venting of the pressure relief valve, and inspection of gas pipes.

Subscribe to Daily Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.