A recent experience of mine...
On rescuing a truck from a pit at one of my work sites, when a crane could not reach the truck to pull it out.
The truck's rear right tyres were stuck in a pit, and the rear left tyres were lifted off the ground.
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..it was 1:00 AM...and we had to hurry up...
The underside of the stuck truck as seen from side-front. You can see the sunken right-rear-tyres.
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The left rear tyres can be seen here.
They are lifted off the ground. (As seen from side-front).
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Work begins...A jack is placed on the rear left tyres as shown above and the tyre is lifted slightly. Aim is to add traction under and around these tyres using bricks, before starting the truck engine and accelerating to pull out of the pit.
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You can see the bricks that have been added under and slightly on the side of the sunken rear-right- tyres....
The bricks will provide the necessary traction (via friction) for the truck to pull out when it is accelerated.
Without these bricks, there will be no traction because the pit has wet, loose mud and nothing else.
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Adding bricks for support to the tail of the truck, behind the sunken right-rear-tyres. These bricks will provide support when the jack is removed, just before the truck is accelerated out of the pit.
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The left-rear tyres again, in this picture.
They have managed to touch the ground, thanks to the jack under the right-rear-tyres...
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Adding traction to the side of the left-rear-tyres.
(as seen from the side-back of the truck.)
The jack is removed from under the sunken tyre slowly....and...
WE ARE NOW READY TO SWITCH ON THE ENGINE AND PULL OUT OF THE PIT!!!!
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The truck pulls out of the pit in the first attempt!
Precautions in such a scenario:
1. The vehicle must be emptied of its payload to reduce its weight.
2. The jack must be provided with a stable base, as shown in photo 3.
3. The jack must be removed from under the sunken tyre before acclerating the truck out of the pit.
4. The tyres must REST on the bricks under the tyres. If the weight of the tyres does not fall on the bricks, there will not be sufficient traction to pull the stranded truck/car etc. out of the pit.
