Originally Posted by BobT
It's an impressive video. I'm an Engineer and judging by the presenter's language, I'd guess the script writer, is an Engineer also. He makes an interesting point that their tests show that the dynamic load required to snatch a vehicle out of a bog is not much different to the mass of the vehicle. Off the top of my head, I would have thought it would be much higher. Chief Products decided to go with a working load limit of 4,500kg for their recovery hooks. These are Engineer certified. Not sure if Uneek's hooks are engineered. They may be. Where they say their hooks are "rated" at 3,000kg they probably mean working load limit but it's not clear.
I saw this and thought I'd post a quick reply.
Based on our research, 1.5 times GVM is considered the engineering standard for recovery points. This is probably why Jeep engineered the front mounting points to 4,500kg and the Jeep Australia Hook is rated to 4,500kg WLL.
The presenter in the TJM video mentions that the forces in a typical snatch recovery are about the same as GVM, which is correct, but a good recovery point should also be able to withstand the forces of a more seriously bogged (non-standard) recovery. Bury that same Ford Ranger in mud 6 inches deeper and those recovery forces will go up significantly. It should also be noted that the curb weight of a dual cab Ford Ranger is about 300-500kg less than a GC, although the trailer in the video probably makes up for that.
Using a bridle strap to distribute recovery forces over both recovery points can be extremely helpful, (and recommended) but there are a few things to remember. First, the WLL when using a bridle strap with (2) ecovery points is only 80% of the combined ratings, 3000kg * 2 * 0.80 = 4800kg (not 6000kg). Second, this rating drops quickly if the pull is not directly in front of the vehicle, because the loads are unequally distributed to the recovery points.
Finally, keep in mind that many will also want recovery points that can be used with a winch. For a 10,000lb winch that would be about 4500kg.
I hope that helps!
MY15 WK2 Overland // 5.7L Hemi + Quadra-Lift // Granite Crystal + Custom Black Trim
275/70R18 Mickey Thompson MTZs + Mopar 18" Off-Road Wheels
Mopar Rock Rails + Mopar Skid Plates + Mopar Tow Bar + Rhino Rack
- [2-Recovery Points (Flame Red) + Sump Protection Plate + Transmission Protection Plate + Lower Front Guard + Nudge Bar + Rear Bumper Guard + Hidden Winch Mount + Latest Prototypes]
MY15 WK2 SRT
Black + Black
Build Planned -- Kooks Headers + Supercharger