Surface damage risk from a 50 ton

[climbingmonkey24]

My crane contractor just got a 50 ton. I’m curious how high of a risk there is of cracks / sinking on driveways from it. Even with proper matting and setup, is it still high risk? Took much of a risk to be worth it?

I watch guy’s like Reon Rounds who brings his large Grove into areas many might try to avoid, and what they are doing seems to be working well in terms of minimal impact.

It also has me thinking if I was to use it, I might need to be transparent with the clients that there is a risk, and perhaps have them sign a liability waiver…?

 

[Jehinten]

Your axle setup will make a difference but we use a 50 ton with minimal issues. The only driveways I've seen crack are already extensively damaged, however he makes a conscious effort to stay off of the "dog ears" where a driveway ties into the street.

Lawns can be driven on when rock hard with no matting (largely clay here) but watered lawns can leave a slight depression even with 4' wide mats. If you have the mats to double them up, it avoids depressions in even wet lawns. Mats on mats do slide easy. Keep that in mind on slopes or when turning the tires.

A good operator can tell the angle of approach he needs to take before getting in there to cut down on trying to wiggle the truck over and causing more wear with the driving back and forth.

 

[Reach]

Noting that the 50 ton crane you are referring to is a three axle all-terrain crane might be worth a mention.

I don't know what that crane weighs, we work with a very similar 65 ton crane, which weighs about 80,000 pounds as it goes down the road. Driveways generally survive, but our operator is very good, and knows how to not turn the wheels when the crane is not rolling. Still though, we have done some damage to driveway edges, especially on very narrow driveways where we can't avoid the edges.

 

[climbingmonkey24]

Your axle setup will make a difference but we use a 50 ton with minimal issues. The only driveways I've seen crack are already extensively damaged, however he makes a conscious effort to stay off of the "dog ears" where a driveway ties into the street.

Lawns can be driven on when rock hard with no matting (largely clay here) but watered lawns can leave a slight depression even with 4' wide mats. If you have the mats to double them up, it avoids depressions in even wet lawns. Mats on mats do slide easy. Keep that in mind on slopes or when turning the tires.

A good operator can tell the angle of approach he needs to take before getting in there to cut down on trying to wiggle the truck over and causing more wear with the driving back and forth.

Do you notify the clients that there could be the potential for some damage, or have them sign a liability waiver or include it in contract?

 

[Lumberjack]

My crane contractor just got a 50 ton. I’m curious how high of a risk there is of cracks / sinking on driveways from it. Even with proper matting and setup, is it still high risk? Took much of a risk to be worth it?M

It also has me thinking if I was to use it, I might need to be transparent with the clients that there is a risk, and perhaps have them sign a liability waiver…?

It’s entirely up to you and the customer if it’s worth it or not.

High risk or low risk is relative and qualitative, not quantitative.

Of course inform the customer of the risk, and definitely have it in your terms and conditions.

Do you notify the clients that there could be the potential for some damage, or have them sign a liability waiver or include it in contract?

Absolutely, yes, of course.

My telehandler is only 50klb but it’s on two axles. Edges of concrete are the weak point. Four wheel steer is invaluable for putting the tires where you want them while maneuvering.

Two layers of plastic mats are worthless to prevent depressions on “wet” yards. They will help you not get stuck. Layers of mats are slick and squirm like the other guy said.

Plastic is also near worthless for driveway protection. 3/4” plywood is ~15-20x stiffer than 1/2” plastic mats. Layers matter, gaps and seams are pressure points.

Swamp mats are meaningful protection for yards. I hope 2” plastic mats are as well.

It’s rare we meaningfully break concrete that is a proper thickness that isn’t undermined. The two times I remember breaking concrete, the thickness was 1.5-2”. On one the outrigger punched through, there was standing water in the sand that supported the 1.5” slab.



The other was a driveway, relatively minor damage (existing matching breaks diagonally across the driveway). I told the customer, they were fine with it. We did a fantastic job at a fantastic value. I explained the risk at the bid.

Neither break had mitigating efforts made. If the customers had expressed concern, mitigation is an option that just costs money.

Excavator did this, the RTH got another spot but it didn’t displace as much.



Outrigger loads are definitely something to consider and design/accommodate for. My RTH can put 46klb on an outrigger and it came with laughably small 2’ square pads.

 

[oceans]

I will definitely agree with Lumberjack on the wood vs. 1/2” poly mats. Poly is popular because it lasts so long, but it definitely will allow depressions to form.

It’s also a real good idea to know the crane’s footprint and setup location. You’re best off ensuring the outriggers will be on solid footing and have room for full extension where required.

I would begin a relationship with a crane company by looking at a job or two with the owner/operator to make sure a proper setup can be attainable. After a few go-rounds, you should be able to make that determination on your own but also scout the outrigger points as well.

Getting heavier trucks into some driveways can also look easier than it is in practice. Steep, short inclines can be fine for a Prius but very tough in a larger truck. Sometimes you need enough people on the job just to spot the machine on the way in and out. You also need to hope to work with a skilled and conscientious operator.

All that said, you’ll be best off to let the client know what they’re getting into and the potential for damage is there. From there, you can decide whether a formal release of liability is appropriate. I can’t recall ever having to do it myself but we also take extensive measures to protect people’s property.