Scary 4wd moment

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Discussion

GravelBen

Original Poster:

15,723 posts

231 months

Saturday 7th June 2008
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Thought you lot might appreciate this one...


You can see faint tracks on the right where I went up (2nd gear low range for perspective, they never look as steep in photos), and not-so-faint track on the left where I came down a lot faster going backwards:




A closer look:




Where I finally managed to reverse out of it (truck is exactly as it stopped), just before it would have got a whole lot worse:





One of the scarier moments I've had in a work vehicle eek








signia

479 posts

225 months

Saturday 7th June 2008
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eek

at what point did you decide to stay in the car, rather than bail out?? That could easily have been the wrong call biggrin

Nice looking area though.

GravelBen

Original Poster:

15,723 posts

231 months

Monday 9th June 2008
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hehe The thought did present itself in the back of my mind, but I thought I had space to get it back, and more space after that to get out if we had to. The angle we were coming down on I couldn't actually see the big rock about 10m further down the hill that would have most likely rolled the truck if we went over it.

Certainly got the adrenaline going, I can tell you that!

normalbloke

7,471 posts

220 months

Monday 9th June 2008
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Why did you end up coming down backwards out of control?
Lessons learnt?

GravelBen

Original Poster:

15,723 posts

231 months

Monday 9th June 2008
quotequote all
Was going fine until part-way up the steepest bit when it lit up all 4 wheels very suddenly and took off backwards. Probably would have gone up it if the rear tyres had a bit more tread (had come down it 10 min earlier with no problems) but they're well due for replacement (blame my boss for that one!).

There wasn't much more I could have done AFAIK, I grabbed reverse as soon as it lost forwards momentum and tried to slow it gently with engine braking but as you can see once it had started to rip through the grass into the wetter soil underneath there wasn't much grip to do anything - perhaps if I'd accelerated harder earlier once in reverse to get the wheels going faster than the slide then I might have been able to slow it from there, but then again perhaps not and I didn't want to gain any more speed than I had to in order to keep directional control.

I don't have a lot of 'proper' off-road experience, its the first time I've been in that situation (have had to back off climbs before but always more controlled) so any useful advice from more experienced off-roaders would be welcome.

pugwash4x4

7,537 posts

222 months

Thursday 12th June 2008
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GravelBen said:
I don't have a lot of 'proper' off-road experience, its the first time I've been in that situation (have had to back off climbs before but always more controlled) so any useful advice from more experienced off-roaders would be welcome.
First mistake was to confuse a open green field with something safe to drive up!! I always get the sts going across open fields as there is nothing to slow you down once you start sliding and it is very very easy to get sideways unless you anticipate.

A couple of things that could have helped:

Accelerate- you wouldn't have gained much more speed but you would have picked up some traction which would have given you the ability to steer.

Cadence brake- if you don't have the confidence to accelerate then learn to cadence brake properly- i think you probably could have stopped on that hill with a bit of cadence braking.

One technique that would have worked with the right knowledge (but would have utterly trashed the hillside- and i mean utterly) and if you are really brave/silly then you could have left it in first near the top and booted it to get all 4 wheels spinning- what happens is that you can use the angle of the slope and your steering input to slide sideways across the hill to the lowest point. I DO NOT recommend this tecnhique without a roll cage and a lot of experience- works well with triallers and such like though and could work if you were totally desperate- ie you had a cliff right behind you!

hobbiniho

109 posts

192 months

Saturday 14th June 2008
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could you not have done a j-turn so you were pointing down the hill the right way, so you could drive to safety????

pugwash4x4

7,537 posts

222 months

Saturday 14th June 2008
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i'm not sure if you're being serious or not?

normalbloke

7,471 posts

220 months

Saturday 14th June 2008
quotequote all
hobbiniho said:
could you not have done a j-turn so you were pointing down the hill the right way, so you could drive to safety????
tank

That I'd like to watch!

GravelBen

Original Poster:

15,723 posts

231 months

Sunday 15th June 2008
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hobbiniho said:
could you not have done a j-turn so you were pointing down the hill the right way, so you could drive to safety????
hehe To be honest when the nose started to swing out in a not-coming-back-anytime-soon way I thought about that - decided I really didn't want to be sliding down it broadside, so planted the boot properly in reverse, as it happened it got enough traction with the front tyres to push the back end round and uphill to stop the truck but until the fronts bit I was thinking 'at least I'll get it facing downhill to see where I'm going'. Funny what goes through your head at times.

GravelBen

Original Poster:

15,723 posts

231 months

Sunday 15th June 2008
quotequote all
pugwash4x4 said:
GravelBen said:
I don't have a lot of 'proper' off-road experience, its the first time I've been in that situation (have had to back off climbs before but always more controlled) so any useful advice from more experienced off-roaders would be welcome.
First mistake was to confuse a open green field with something safe to drive up!! I always get the sts going across open fields as there is nothing to slow you down once you start sliding and it is very very easy to get sideways unless you anticipate.
The same surface had been fine up until that point, and jobs take a whole lot longer to get done if you walk everything that doesn't have a track on it. But I agree on the general point, flat grass is fun, steep grass isn't.


pugwash4x4 said:
A couple of things that could have helped:

Accelerate- you wouldn't have gained much more speed but you would have picked up some traction which would have given you the ability to steer.
yes I was on the throttle most of the way down but thinking about it not enough, reverse in low range being very low geared meant that despite being on the throttle to a degree the wheels were still under some engine braking and trying to go slower than ground speed.

pugwash4x4 said:
Cadence brake- if you don't have the confidence to accelerate then learn to cadence brake properly- i think you probably could have stopped on that hill with a bit of cadence braking.
I don't think it would have done anything in this case - even a very light touch on the brakes caused it to pick up speed, those big brown marks down the hill were not caused by locked wheels - 98% of the way down I was in reverse and on the throttle.

pugwash4x4 said:
One technique that would have worked with the right knowledge (but would have utterly trashed the hillside- and i mean utterly) and if you are really brave/silly then you could have left it in first near the top and booted it to get all 4 wheels spinning- what happens is that you can use the angle of the slope and your steering input to slide sideways across the hill to the lowest point. I DO NOT recommend this tecnhique without a roll cage and a lot of experience- works well with triallers and such like though and could work if you were totally desperate- ie you had a cliff right behind you!
I have seen triallers do this on TV but again I don't think it would have worked there given how quickly it took off backwards once the wheels started to spin.


Thanks for the advice, on reflection the biggest single factor was probably the lack of tread on the rear tyres, there were no problems with traction coming down it forwards and it drove out of the slide pretty quickly once the nose was downhill.

Edited by GravelBen on Sunday 15th June 10:31

DennisTheMenace

15,603 posts

269 months

Tuesday 17th June 2008
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Sorry to go O/T but is that a trimble GPS back pack by the rear of the toyota ??

used them years ago when surveying with fujitsu tablets , 1 job i really miss smile

GravelBen

Original Poster:

15,723 posts

231 months

Wednesday 18th June 2008
quotequote all
DennisTheMenace said:
Sorry to go O/T but is that a trimble GPS back pack by the rear of the toyota ??

used them years ago when surveying with fujitsu tablets , 1 job i really miss smile
Close - we use Leica GPS smile Have to agree with you about the job - not bad getting payed to play with GPS, go 4WDing and see some pretty cool places.