Recommendation Date
Recipient Name
Toll NZ Consolidated
Text
check all generator units similar to AL2073 to ensure that the cooling airflow is adequate and unrestricted within the generator enclosure around all parts of the diesel engine and the alternator housing, and that ther is no build up of diesel oil or dust particles.
Reply Text
Toll NZ have considered re-installing filters on the cooling air intake however experience has shown that while filtering the dust particles entering the generator enclosure this also restricted air intake to the point that the sets ran hot and shut down in the Rimutaka Tunnel.
Investigations carried out have shown that with the air intake filter removed the cooling airflow in the generator enclosure is sufficient. Regular cleaning takes place every 24,000 km (approximately every three months) and whenever the oil is changed.
Toll NZ considers that the most likely root cause of the fire was a hot cinder from the locomotive exhaust being pulled in through the air intake and sitting on an oil impregnated part of the DA set sound insulation causing it to eventually ignite.
Covering the existing insulation with Flamestop insulation to prevent oil impregnation and contact with hot cinders will prevent a repeat of this incident. We intend to have this installed in all AL generator cars by the end of 2005.
Investigations carried out have shown that with the air intake filter removed the cooling airflow in the generator enclosure is sufficient. Regular cleaning takes place every 24,000 km (approximately every three months) and whenever the oil is changed.
Toll NZ considers that the most likely root cause of the fire was a hot cinder from the locomotive exhaust being pulled in through the air intake and sitting on an oil impregnated part of the DA set sound insulation causing it to eventually ignite.
Covering the existing insulation with Flamestop insulation to prevent oil impregnation and contact with hot cinders will prevent a repeat of this incident. We intend to have this installed in all AL generator cars by the end of 2005.
Related Investigation(s)