A question needs be asked of witnesses before finer "analysis" is undertaken: Did the bus suddenly belch thick black smoke before it raced and plunged into the river? If yes, this (the uncontrollable speed) could be the result of diesel overrun (or runaway). "In many vehicles, a crankcase breather pipe feeds into the air intake to vent the crankcase; on a highly worn engine, gases can blow past the sides of the pistons and into the crankcase, then carry oil mist from the crankcase into the air intake via the breather. A diesel engine will run on this oil mist, since engine oil has the same energy content as diesel fuel, and so the engine revolutions increase as this extra "fuel" is taken in. As a result of increased revolutions, more oil mist is forced out of the crankcase and into the engine, and a vicious cycle is created. The engine reaches a point where it is generating enough oil mist from its own crankcase oil that shutting off the fuel supply will not stop it and it will run faster and faster until it is destroyed." http://en.wikipedia.org/wiki/Diesel_engine_runaway Oil diluted by diesel fuel leaking into the engine crankcase (raising the oil-level sufficiently high) can also give rise to such an effect if the piston rings suck in the diluted oil and burn that instead of the injected fuel, as the engine temperatures will be high enough to produce combustion of the heavier distillate.This can happen if the rings are worn out or sticky. In April 1975 (post University exams), I was travelling in a bus from Panjim to Margao via Ponda. The revs all of a sudden started rising, the driver had the presence of mind to put the vehicle into neutral, switching off the diesel supply (the revs kept on rising to a high cresecendo), then he and the "cleaner" quickly yanked open the engine cover, and dropped a large wooden block into the air-intake, when the engine came to an abrupt halt. These guys probably had experienced or heard of such experiences before, so knew what to do. Prevention? Training and plain common-sense daily checks of the levels of engine oil, braking and cooling systems before the start of the day. Just my thoughts. As to victims of the tragedy, may their souls rest in peace, and condolences to their near and dear. http://www.myturbodiesel.com/1000q/stop-runaway-diesel-engine-how-to.htm http://community.discovery.com/eve/forums/a/tpc/f/9701967776/m/22619134501
Gabriel. >________________________________ > From: Goanet News <[email protected]> >To: "Goa's premiere mailing list, estb. 1994!" <[email protected]> >Sent: Monday, 20 February 2012 6:43 AM >Subject: [Goanet] CALVIM TRAGEDY: Serendipity to the rescue for some villagers >... When the going got tough... To inspect bus.... (Andrew Pereira, TNN) > > > >PANAJI: The transport department will inspect the ill-fated bus 'Shree >Ganesh' on Monday to determine whether it was mechanical failure or >human error that caused it to plunge into the river at the >Calvim-Aldona ferry wharf, transport director Arun Desai told STOI. > > --------------------------------------------------------------------------- Protect Goa's natural beauty Support Goa's first Tiger Reserve Sign the petition at: http://www.goanet.org/petition/petition.php ---------------------------------------------------------------------------
