Moving something extremely heavy? Tens or hundreds of tons?
The path to moving something heavy from point A to point B always comes with challenges. Sometimes that means spanning gaps.
This can happen when offloading or transloading from a delivery vehicle. Or it can happen when moving across a worksite with trenches, pits, drainage channels, or other gaps.
The forces involved with a very heavy item are enormous, the consequences of failure severe, and many of the quick fixes or workarounds that may work for lighter loads are simply not an option.
In this article, we’ll describe the four most common ways to span a gap when moving very heavy loads:
- Hydraulic Skidding Systems
- Bridging
- Backfilling
- Crane Lifts
4 Ways to Span a Gap When Moving Heavy Loads
Here are the four most common ways to move a heavy load across a gap. Each of these methods has its place depending on the weight, the width of the gap, and the conditions on your worksite.
1. Hydraulic Skidding Systems
Hydraulic skidding systems can be used to span gaps from a few inches up to a few feet, depending on the model of the system. This makes hydraulic skidding a strong option for routine gaps such as the gap between a transport vehicle and a dock.
Operators should be very careful to ensure that the system being used is rated to handle the distance of the gap. If your team tries to span an unsupported gap longer than the recommended distance, the system could fail, and the load could fall into the gap.
Note: Hydraulic skidding is often combined with other techniques on this list when moving very heavy items. For example, for a longer gap, a crew may build a temporary bridge, then use hydraulic skidding to move the item across the gap.
2. Bridging
Temporary bridging is a common approach to spanning a gap. For narrower gaps and lighter loads, this can sometimes be as simple as laying heavy steel plates across the opening. For wide gaps and heavier loads, teams may build more stable structures using steel beams, heavy timber, or engineered cribbing.
Note: Bridging introduces a significant amount of work and costs into a project. A crew must have access to the right materials and expertise to successfully support the item across the gap. The bridge must also be removed before the move is complete.
3. Backfilling
In some cases, crews may be able to fill the gap with compacted material such as gravel, crushed stone, or engineered fill. In this way, the load can cross on a continuous surface. After the move, the fill is removed, and the gap is restored.
Note: Backfilling only works when the gap can be temporarily filled without causing other problems. Backfilling is not an option if the gap houses active utilities, serves as drainage, or needs to remain open for structural reasons.
4. Crane Lift
Finally, if a crane is available and conditions allow it, the load can be lifted over the gap. This avoids the problems associated with bridging and backfilling, but it also introduces all the challenges that come with crane lifts. The space must have overhead clearance and room for the swing radius of the crane. You must also have operators skilled in rigging and an experienced crane operator.
Note: For loads that are sensitive to tilt or dynamic forces, crane lifts may not be practical.
Choosing the Right Approach to Span a Gap
If you’re already using a hydraulic skidding system, you may not need anything more to span small gaps. Just make sure the gap to be spanned is within the capabilities of the system you’re using.
In other situations, temporary bridging or backfilling combined with hydraulic skidding might be the perfect mix of methods to ensure you can move your item across the gap safely. These methods keep the load grounded and controlled across the gap.
If you are planning a move that involves a gap and you want help evaluating if hydraulic skidding is a good option, reach out to the team at Hydra-Slide. We can review your situation and recommend a skidding system that matches your unique project.
