Hydraulic Spreader as Lifting Equipment: What is Possible?
Even though lifting a vehicle with a spreader isn’t what it’s specifically designed for, it does happen in real life.
A spreader can be used to lift cars, farm equipment, and other heavy objects during entrapment or
emergencies. In cases where quick action is needed to free someone trapped under a vehicle, a spreader
can be effective, as long as you understand its limitations and the risks involved.
This document explains those limitations and helps you avoid risks. We cover these seven topics:
- Weight of the load
- Stability of the spreader
- Support of the spreading tips
- Available space for placing the spreader.
- Do’s and Don’ts
- Lowering a load
- Spreading tip widening accessories
The spreader discussed in this document is the PSP40, but the general principles are valid for all
Holmatro spreaders. You will find the technical specifications of the PSP40 and all other spreaders on
the Holmatro website.
1. The Weight of the Load
Important to note: the spreading force is at its lowest when the arms are fully closed. As the spreader
arms open wider, the force increases.
The spreader’s strength is tested according to the EN13204 standard, 2.5 cm from the tip (refer to SP1 in
the graph).
The minimum force (at SP1) is 43 kn / 4.4 tonnes. The maximum force (at SP1) is 77 kn / 7.8 tonnes
What practical use does this have?
The key takeaway is that the maximum load should never exceed the minimum spreading force of the
spreader.
To put it simply: If a heavy load is tilted and you use a spreader to level it out, the spreader arms will close
during this process. As the arms close, the maximum load capacity decreases, but the effective weight of
the load increases due to the angle change. This can result in overloading the tool and potentially causing
material failure.
2. Stability of the Spreader
Spreader arms outline a parabola when opened.
The spreading tips don’t move in a straight line; instead, their position changes as the arms open, following
a parabolic path. This also affects the stability of the spreader, which shifts more onto the points than
remaining flat.
The lower arm on the surface tends to shift when the upper arm grips the object. If one of the spreading
tips doesn’t have enough contact or grip at the start, it might shift or even slip completely as the arms
open further.
Fig. 3 illustrates that while the lower spreading tip provides sufficient support, the upper tip bears the load at the maximum end and can shift rapidly as the spreader opens more.
Note: To prevent a load from dropping, it is essential to secure it with chocks or similar devices. As the spreader opens, it becomes more prone to
lateral movement, which can lead to the spreading tips slipping. This brings us to the next point: support of the spreading tips.
3. Support of the Spreading Tips
Fig. 4 shows that the upper spreading tip engages the object sufficiently, reducing the likelihood of
shifting. The lower spreading tip supports the entire surface, providing stability.
It’s essential to fill the empty space between the ground and the object as much as possible. This
minimizes the spreader opening, allowing the spreading tips to have maximum grip. Lifting the object
must stop immediately if the lower spreading tip detaches from the blocking material. In this situation, the
tip carries the load on the very edge, creating an unstable situation.
4. Available Space for Placing the Spreader
Cribbing under the spreader must be stable and wide enough to provide sufficient support for the lower
spreading tip. The gap between the object and the cribbing must be large enough to position the spreader
far enough under the object. The spreading tips need to have adequate support, at least 4 cm.
If there isn’t enough space, you cannot position the spreader correctly.
If there is too much space, the support surface changes significantly during the lifting movement.
5. Do’s and Don’ts
DO Open the spreader until the support surface of the spreading tips decreases
DON’T continue if you reach the extreme position!!!
Stop immediately if the spreader no longer provides full support!
6. Lowering a Load
All double-acting hydraulic rescue tools are
equipped with pressure-controlled check valves
(PCCVs). These valves prevent the tool from closing unintentionally due to external forces unless
deliberately operated. When lowering a load, the oil
pressure in the tool can exceed the pressure that
the PCCV maintains to keep it open. In this case,
the PCCV will close.
As the oil pressure from the control handle increases, the valve opens again, allowing the load to lower. Subsequently, the pressure in the tool increases again, causing the PCCV to close once more. The operator then raises the pressure, causing the valve to open again. This process can occur very rapidly, with the valve opening and closing multiple times per second. This results in a jerking effect on the load and the spreader during descent, which introduces additional dynamic forces and can lead to dangerous situations or damage to the spreader.
Holmatro therefore advises that a lifting operation with a spreader should only be performed in emergencies and, if possible, the load should be kept elevated. It is preferable to stabilize the load with material that can later be removed by a recovery team. Safely lowering a load with a spreader is practically nearly impossible. In controlled situations, where no rescue is involved, it is better to wait for the arrival of suitable lifting equipment, such as lifting bags.
7. Spreading Tips Widening Accessories
Using accessories that widen the spreading tips during lifting may exceed the international design
guidelines for the safety and performance of hydraulic rescue tools, as outlined in standards such as
EN13204 and NFPA 1936.
We are aware that various parties have introduced spreading tip widening accessories to the market,
such as the SHUB or TL-9. While lifting accessories like the SHUB or TL-9 can enhance stability during
lifting, they can also result in unacceptable lateral forces on the spreading arms. These lateral forces can
negatively impact the integrity and safety of the spreader.
Holmatro cannot accept product liability if a Holmatro spreader or combi tool is used in
combination with an accessory that is wider than the original spreading tip.
Closing note
The load must always be properly stabilized before starting the lift. During the lifting process, it should
be fully supported to avoid sudden drops if the spreader shifts or tilts due to incorrect use. Mechanical
securing of the load is essential, even when using hydraulic tools for lifting.
Marinus Verweijen & Juul de Graaf
Holmatro Rescue Consultants