After e-buses, WBTC set to roll out CNG vehicles with flexi-fuel option
Kolkata: After running electric buses successfully, West Bengal Transport Corporation (WBTC) is set to introduce five buses retrofitted with compressed natural gas (CNG) engines, apart from their existing diesel engines. These buses can switch to diesel, if CNG is not available. Apart from reducing the carbon footprint, the use of CNG will also lead to savings on costlier diesel. WBTC ran buses on trial with CNG, a cleaner fuel, after Bengal Gas Company Limited (BGCL) set up a CNG dispensing station at its Kasba depot. “The CNG kit was retrofitted with old BS-II buses and the trial run was successful. The buses will retain diesel engines, with BGCL supplying CNG in caskets. Once the CNG pipeline is ready and the supply is steady, we may do away with diesel engines in phases,” said a WBTC official.
We are focusing on electric buses and now CNG so that Kolkata can become greener and cleaner,” said transport minister Firhad Hakim. He reiterated that the state transport department has taken various steps for e-buses earlier. “Now steps are being taken for CNG buses. There will be a significant reduction in vehicular pollution with the introduction of CNG fleet in Kolkata and saving fuel cost to the extent of 25-30%,” said Hakim. According to WBTC sources, two fuel tanks will be used — 40% CNG and 60% diesel. WBTC installed dual fuel kit —each worthRs1.5 lakh —in five buses at Belgharia depot through a private agency. This is cheaper when compared to the expensive CNG engine that costs Rs 5 lakh per bus. South Bengal Transport Corporation (SBSTC) also adopted the same technique for some of its buses. However, the trial of flex-fuel — the use of diesel when the bus is in first and second gear and automatically switches to CNG in higher gear — had some troubles like knocking and other problems with the engine. “Frequent gear changing on the city roads with different fuels like diesel and CNG may cause engine knocking due to random change of fuel and resultant fall of fuel pressure in combustion engine. The hybrid system necessitates software logistics to strike the crucial balance,” said Somendra Mohan Ghosh, an engine combustion expert.