Set up the snatch on the picture: type both vehicles' mass and the strap's breaking strength on them, pick the strap or rope, and drag the speed. Everything updates as you go.
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Try:
Strap
On the vehicles
Speed when it goes tight
SECURETECH suggests 18 km/h for two vehicles of similar mass (source).
The snatch, moment by moment
Force in the strap
Strap or rope for the stuck vehicle
Shackles, steel and soft
Pull on the shackle off in-line
kg
Safety straps: three different jobs
A safety lanyard, a tree protector and a bridle all look like short straps or ropes, but each does a different job and is rated differently. Don't swap one for another.
1 Safety lanyard holds the gear if something lets go
2 Tree protector ties the rope to the anchor
On a single line, at most your winch's rated pull, in kg.