Manufacturing defect likely cause of BEST bus fires

Mumbai: A manufacturing defect is likely to have caused the recent incidents of fire in three Bharat Stage-6 BEST buses according to BEST officials

Mumbai: A manufacturing defect is likely to have caused the recent incidents of fire in three Bharat Stage-6 BEST buses according to BEST officials. Bharat Stage-6, which came into effect in April 2020, is the latest emission standard to regulate pollutants from the exhaust of vehicles.

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The probable manufacturing defect was gauged during a detailed 20-day inspection of the 400 CNG non-AC buses manufactured by Tata Motors and being operated on a wet lease by M/S Mateshwari Urban Transport Ltd. The entire fleet was withdrawn after the incidents of fire, and it finally came back on the roads earlier this week. Hindustan Times had reported this in an article on March 15.

“There is every likelihood that there are manufacturing issues with these BS-6 buses,” said a BEST official on condition of anonymity. “These are new buses which are 1 to 1.5 years old, and yet we had to replace their engines. Even in the initial period, the buses were frequently breaking down; everyday 10 to 15 of them had to be towed away.”

Engineers from Tata Motors were in the inspection team that investigated the reasons behind the fire that engulfed three BEST buses. During the 20-day period, engines and their parts were replaced, loose accessories that were allegedly causing the engine to heat up were removed and important safety measures were put in place. Sources said that even vital equipment was airlifted and brought to the site.

“During the checks, we found that there was gas leakage in some of the engines,” said a senior BEST official. “We also found that the engines were generating excess heat. In these 20 days, many accessories inside the engine were replaced, including the CNG tubes, and necessary steps were taken to reduce the heat in the engines.” The official added that as the buses were brand-new ones under warranty, the wet lease operator could not be blamed for failing in their upkeep, as Tata Motors had initially alleged.

A senior BEST official told HT that though they were yet to get a thorough report from Tata Motors on the reasons behind the fire, the probable cause was friction between the engine components and the portion of the CNG supply tube that was in close proximity to them. BEST authorities claim that the bus manufacturer agreed that there were serious issues with the buses. “If we hadn’t taken up repair works, the problem would have been addressed in a piecemeal fashion,” said the official. “The wet lease operator has informed us that the annual maintenance contract has been given to the manufacturer, Tata Motors.”

Sources said that it had taken a longer time to deliver these buses reportedly due to issues with the engines. Meanwhile, when Hindustan Times sought a reply from Tata Motors over email, the spokesperson responded: “Tata Motors is committed to offering safe and high-quality vehicles for public transport. The recent thermal incident had occurred in the CNG buses owned, maintained and operated by M/S Mateshwari Ltd under a separate commercial contract with BEST without any involvement of Tata Motors. At BEST’s behest, our team of experts coordinated with them and supported the operator M/s Mateshwari in identifying and taking the requisite corrective action. Details of the findings have been shared with BEST and all the buses have been handed over back to the operator, M/S Mateshwari.”