Job Site Safety
When stucks lead to yanks and pulls there’re right ways and wrong to make the connection — and shackles are the key link
by Jim Allen
Getting mired down on a job site is easy to do in the earth-moving world of construction. Driving over soft, sandy soil, through mud, or any combination of terrain that compromises a pickup’s traction can led to getting stuck.
Quite often the stuck vehicle doesn’t have a winch. So the driver’s only option is relying on another vehicle or piece of equipment to lend a pull to get back on track and on with work.
Fortunately, just about every pickup has solid hookup points at each end of a pickup can be useful tools that you don’t have to worry about losing.
These attachment points can be used for anything from recovering your vehicle, or another, emergency towing or to convert the solid bulk of the truck into a dead-man for a variety of other work.
A hookup point is a spot to which a hook or ring can be attached and handle high levels of brute force. That usually means a chassis-mounted spot, or a heavy bumper or bracket that is chassis-mounted.
It needs to handle the weight of the loaded vehicle, with a bit of overload factored in for safety. It should also be in a place where angle of the tow strap, chain, rope or cable will not contact with any part of the body or interfere with the operation of chassis components.
Such recovery points can be welded or bolted in place. Just keep in mind a welded point is only as good as the welding and bolted parts are only as good as the bolts used.
Shackles and Pins
Having an attachment point without a way to connect a strap, cable or chain to recover the pickup is useless. So it pays to have a strong, quick way to make the connection when needed.
Shackles are the most common connectors, and the best types for pickups in the field are anchor or “bow” shackles.
The bow shackle has a larger “mouth” than the “D”-shackle. The bow shackle is ideal for use on pickups used for off-road purposes as it allows a larger strap to be used when self- or assisted-recovery is necessary.
In general terms, both types are correctly called a screw-pin shackle, or clevis as the pin screws into the shackle for a secure lock.
Shackles are classified by the diameter of the metal in the bow. In the truck world, the common sizes are 3/4-, 7/8- and 1-inch.
The thicker the material, the stronger the shackle. The type of material used to make the shackle also plays a part and there are better and worse steels used. Don’t skimp on quality of product in this arena as safety plays a big factor when it comes to pulling.
When you buy shackles focus on one specification: The Working Load Limit (WLL).
Quality items will have a Working Load Limit (WLL) cast, stamped or engraved onto the piece, or at least specified by the manufacturer in some way.
If there’s no WLL rating, don’t use it on your pickup.
WLL is the actual load the piece is designed to carry as rated by the manufacturer. WLL is commonly expressed in tons, U.S. or metric, depending on where the part was manufactured. (One metric ton equals 2,204 pounds, or 1.1 U.S. tons.)
Let’s get this straight first thing: A chain is NOT a good recovery tool when used as the actual pulling device.
Chain is great for a steady load, securing equipment on trailers, or for wrapping around a frame, log or rock when in recovery, or for making an attachment on a chassis where none exists or where chafing might occur on a strap or rope.
But it’s not designed to take sharp, hard yanks.
Because a chain has zero give, it transfers massive shock loads that can break parts and send pieces flying like shrapnel. Chain is a barely acceptable towing device for the same reasons.
A a lot of people have been hurt and equipment damaged when chain is used in towing and recovery. And those are not acceptable liability and insurance risks to take in the construction business.
As for chain strength, there are multiple types available that would work around heavy duty pickup uses: Grade 30 Proof; Grade 43 High Test; Grade 70 Transport (a.k.a. Grade 7 or 700); or Grades 80; and Grade 100 Alloy.
The most common size you’d need are either 5/16- or 3/8-inch links.
For comparison purposes, a 5/16-inch chain will be rated for the following WLL according to grade: Grade 30 at 1,900 lbs.; Grade 43 at 3,900 lbs.; Grade 70 at 4,700 lbs.; Grade 80 at 4,500 lbs.; and Grade 100 at 5,700 lbs.
The hooks on the ends of the chain are rated the same way and should be matched to the chain.
Purpose-built brackets or hooks can be bolted to the vehicle, and sometimes you see them welded on.
These parts may be industrial rigging pieces that have a WLL rating or ones without any stamping or manufacturer rating.
If the latter is the case, don’t chance it.
A good source for heavy-duty pickup shackle attachment brackets is Billet 4X4. They are a provider to a number of the winch and winch bumper manufacturers.
No Recovery Point?
What do you do when a pickup or another vehicle or piece of equipment doesn’t have any hookup points?
Be smart. Think about the forces at work and what is trying to be accomplished.
By all means avoid the axle because it’s more vulnerable than you think. The axle is a tube – hollow inside and prone to cracking or snapping under such loads.
The holes and hooks on the frames used for tie-downs during transport are also a bad idea. They are stout enough for a tow, but are woefully inadequate for a hard yank and often angled wrong for a forward (or rearward) pull.
The best idea is to have a couple receiver hitch shackle mounts in your tool box so you can slide one into the hitch on the vehicle that is helping – or needs help.
If that’s not an option, use a section of Grade 70 transport chain wrapped around a solid part of the chassis to make a hookup point for a strap or winch cable. Avoid all steering related components.
If there’s no other option, the bumper mounting brackets are the last resort. They are usually not designed to take hard yanks – and the air bag sensors could be activated. So tread lightly in this area.