Bus crash investigation findings - hydraulic retarder

[eagle19952]

I wonder if checking operation of a hydraulic retarder in pre trip is soa or if drivers know little about them. I thought normal brakes are required to do the job of stopping, irregardless of supplementary braking assist systems. Maybe driver was inexperienced and was just driving too fast for conditions. Maybe we'll get more detailed info down the road.

The lawyer that hears this on the stand will have a field day...

[chessie4905]

They will have a field day regardless of the situation particulars. Death and injuries are enough to spread the blame to driver, company and their insurance company. Be interested in testimony of passengers.

[Iceni John]

English bus drivers (I hate to say) are probably less experienced than their continental counterparts at descending long steep Alpine roads, simply because there are no roads like that anywhere in Britain.   When I watch the Tour de France mountain stages such as the climb to Alpe d'Huez (where this accident was), I'm always amazed how narrow and steep those roads are, with gradients sometimes exceeding 10% and with dozens of very tight switchback corners.   I would NOT want to take a 12-meter bus up or down roads like that.   Many years ago I took a daytrip by bus up the Gross Glockner Pass in Austria, and that narrow steep road and its vertiginous drop-offs are still fresh in my memory  -  even in a Mercedes O-302 with an experienced local driver it was very scary.

I'm curious if the hydraulic retarder that failed was an add-on like a Telma, or something built into a transmission, or what?   Automatic transmissions in long-distance buses are not common outside USA and Canada, so what did this British-owned bus have?   And how could a hydraulic retarder fail  -  did the oil overheat and catch fire (which could explain why the bus then caught fire), or what happened?   Maybe the fuel tank broke free and started the fire?

Very sobering.

John

[Jeremy]

I was also curious why it should so quickly turn into a complete inferno (to quote the article) after the crash - yes the overheated brake pads would cause a fire, but the speed and ferocity of it suggests something very combustible ignited very quickly - perhaps that was indeed overheated hydraulic fluid from the retarder as Iceni John suggests

I wouldn't presume to comment on the competence of the driver or anything like that but I'd also agree that navigating this type of road with a fully laden coach (and trailer) is an experience that probably very few British coach drivers ever have, and probably not many Italian, French or Swiss drivers either

I notice that the website of the coach operator no longer exists, and perhaps the company doesn't either. Plenty of photos of their vehicles on the web though, and they all look like very modern and high-spec models

Here are a few more photos of the crash site itself









That last photo in particular make me wonder whether the steel frame deformed like that during the accident itself, or whether it sagged afterwards because the steel was softened during the fire. It also makes me wonder whether steel stretch panels (as my bus has) would have contributed anything useful to the strength and stiffness of the frame - clearly fibreglass panels on this bus contributed nothing at all

Jeremy

[luvrbus]

Looking at the side it looks to be started from a brake fire and those babies burn hot in a hurry

[lostagain]

We were trained by Brewster Transport in the '70s how to drive steep mountain roads. Descending steep grades doesn't bother me, but I have, over the years, met some professional drivers who drive down steep mountain roads in high gear, just using the brakes. Just recently, at the truck terminal (no mentioning names) in Lewiston ID, this trucker pulls in, pale faced and quite exited, brakes still smoking, telling everybody how scary the hill into town is... Appalling! I have met some bus drivers in the Rockies that come in from far away in the summer with charters with the same blessed clueless ignorance. They're only as good as you train them.

JC

[windtrader]

A lot of bashing of S&S goes on here but I'm not sure it matters much in a situation like this. OK, so the shell did not fully turn into ash and the metal structure survived. Not sure that is much to crow about but rather humble us all to stay vigilant and aware while moving down the road. I have two extinguishers but adding on the to do list is adding a couple more.