What happens when you shift a mining truck from 6th to 1st

[Secret Chimp]

A massive kablammo:

http://bangshift.com/blog/incredible-carnage-photos-what-happens-when-a-4700ci-caterpillar-mining-dump-truck-engine-explodes.html

[Rupert]

That's baaad, mmkay?

[93JC]

I thought these things had automatic transmissions, or at the very least sequential manuals; I didn't think it was possible to shift from 6th to 1st (barring a mechanical failure).

[giant_mtb]

I thought they were diesel-electric with electric motors running the wheels...wasnt aware there even was a 6-speed in these things........

[S204STi]

Holy God

[93JC]

I thought they were diesel-electric with electric motors running the wheels...wasnt aware there even was a 6-speed in these things........

I don't know jack about any of its competitors but I can tell you with 100% certainty that the Caterpillar trucks have big fucking transmissions that drives big fucking rear axles.

[GoCougs]

A wee bit of Googling shows that that model of Cat mining truck is available both in diesel electric and diesel direct drive.

I have trouble believing you can do that with one of those trucks. It will have some sort of automated transmission which is to say it is easy to build in safeguards to prevent such a scenario (even the cheapest AT cars today can't be downshifted in such a manner).

[MX793]

According to Cat's spec sheet for that model, the transmission does have overspeed protection that will prevent it from being shifted into too low a gear.  I'm not sure what happened to that rig, but I'm not sure it was a missed shift.  Perhaps it went down too steep of an incline which forced the motor into an overspeed condition?  That or some kind of massive transmission failure that stuffed the transmission into too low a gear.  Or maybe the motor seized for other reasons and it started throwing rods and blew itself apart.

[Expeditioner]

Wow.  I literally look at those every day.  The engines, but not CAT.

I've not seen anything so catastrophic.

Productivity notwithstanding, that was a $300k - $400k mistake/malfunction.

Funny how normal it becomes though.  Engines that size, making that kind of power.

[AutobahnSHO]

That's what my SHO looked like, only on a smaller level of course. And the rod was more twisted/bent.  The rod/crankshaft bearing seized and sent shrapnel through the block and oilpan.   

[VTEC_Inside]

Granny shifting... Not double clutching like he should have...

[VTEC_Inside]

I thought they were diesel-electric with electric motors running the wheels...wasnt aware there even was a 6-speed in these things........

That's what I thought.

[Submariner]

I don't know jack about any of its competitors but I can tell you with 100% certainty that the Caterpillar trucks have big fucking transmissions that drives big fucking rear axles.

I think there are large off-road trucks that use diesel electric setups similar to what you get in trains.