by Cris Pasto

If you are working with the right equipment and know how to use it, the most difficult or time consuming task with vehicle stabilization is finding or creating adequate purchase points for both the buttress heads and the base restraints. For those involved in stabilization, this subject is worth some focused consideration. Knowing where to find or make purchase points is a critical step which could make or break your scene efficiency. Note that rust, collision, or other factors may render certain purchase points unsafe and useless. Also be aware that sheet metal and spot welds may fail under load.

Here are a few key principles I apply for purchase point selection and use:

1. Select or create a purchase point that can handle the load.
   
   
2. Select a purchase location which will not damage equipment like strap webbing for example.
   
   
3. Select purchase locations which will not interfere with patient access.
   
   
4. Select purchase points which will not be undermined by or interfere with extrication.
   
   
5. Select or create a purchase point that will cause as little disturbance to the vehicle as possible.
   
   
6. With the above in mind, make the purchase quick !

Factory provided purchase points

The auto manufacturer’s provide us with many components, holes, rails, posts, and pockets that serve as excellent connection points between the stabilization equipment and the vehicle.

Holes: At the undercarriage of a vehicle there are typically a number of holes provided for anchoring the vehicle to transport trailers. These holes are located in many areas, but I can usually depend on finding them at the four corners just inside the four wheel wells. These holes usually work great for stand engagement with a round point head. They also perform well as a strap engagement location, but may require the use of a specialized towing hook as an adaptor between the strap hook and the hole.

Rails or Frame Members: Features such as the "rocker" lip below the passenger doors, frame members, hood/trunk walls, or linear recesses provide for a lip or corner which is easily engaged by a buttress stand head such as a channel, angle, or chisel point.

Roof Posts: I love these purchase points because they are almost always available and provide for a rugged connection. For a vehicle on its side these components are very quick and dependable as purchase points. I use the upper side post for stand head engagement. I can engage the upper post with most cradle-type heads. If glass is intact, it is very easy to get through with little violence. The lower post makes for a base restraint attachment that is perfectly aligned with the stand head engagement. This allows for quick single restraint application. Remember that misaligned head and strap engagement points require multiple base restraints to counteract base loads. I like to engage the post with a J-hook or chain wrap. Avoid wrapping straps around the post as this increases the risk of strap damage from sharp glass and metal.

Misc. Components: There are numerous features not mentioned above which serve well as a purchase point. For example, the front sway bar is a favorite s-hook purchase for me just above the pillow block bearing mount for a side resting car. Many vehicles have 2 convenient hook rings attached to the vehicle front and rear undercarriage. There are many other options that vary from vehicle to vehicle.

"Invisible" Purchase Points

Be on the lookout for "plugged" holes in the underside of the car. Look for both rubber and metal plugs inserted in holes in the sheet metal and sometimes frame members of the vehicle. Often these will not be easily seen due to filth or undercoating, but once you start looking for them, they are readily found.

Look behind objects for purchase points. Knockout a side tail lens and you’ll find a hole in the fender. Break the rear tail light and you may have an adequate recess. Open the gas lid, and you’ve got a pocket. Open the hood or trunk for a purchase point at the fender walls.

Creating Purchase Points

Purchase points may not always be readily available. If the factory does not provide us with purchase points, its time to make our own. There are several ways we can accomplish this. We can apply a chain wrap, we can pierce or drill, and we can enlarge openings..

Chain wrap: I refer to the Res-Q-Jack® chain wrap technique as the application of a "tensioned and restrained" chain. Simply put, it is the application of a chain across or around an object that is tight between attachment points and restrained from separation with the vehicle along its length. These techniques are illustrated in more detail in other articles (See Res-Q-Jack® Roof Resting Stabilization: Full Chain Wrap Method" and "Stabilization With No Apparent Purchase Point"). The chain provides for rapid stand head engagement (heads with chain slots) and in many situations base restraint attachment as well. All that is required is a little know how and creativity.

Piercing: Piercing is not my favorite technique. I look for other means of purchase before choosing this method. I find that this method contradicts our desire to stabilize the vehicle prior to any vehicle modifications that involve such violence, however it may be the only option. Objects that are easily pierced will most likely not resist a great load without purchase point failure such as a fender. A pierced fender may tear easily under a heavy load. Also use caution if piercing the undercarriage as your patient may be near.

Enlarging Holes: Visible holes may be conveniently located, yet not large enough for a head engagement. If the material is not too thick, the haligan and a sledge or flathead axe combined will likely open the hole to a suitable size. Like piercing, this may cause unwanted movement of the vehicle, but it is another option.

Hole saw: Here’s a non-violent means of creating a hole. However, it may be another tool in the box if not yet a part of the tool cache. I find that a hole saw is only good for several holes and you’ll want to replace it in the same fashion you replace reciprocating saw blades.

Fasteners: Here’s an "outside the box" technique I’ve seen performed. It involves screwing a plate to a vehicle surface. The plate is designed to create a purchase point for a strut. This could be expanded into creating purchase for a base restraint as well. You could use the same cordless driver for the hole saw.