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Recommendation For A Crane To Load Logs On A Barge

monoloco

Member
Joined
Jun 6, 2013
Messages
8
Location
Mexico
Greetings, I'm new on this forum and need some info. I work for a timber company in Nicaragua and we need a crane that can move bundles of logs weighing a maximum of 50 tons in approximately a 50-60 foot radius. This will be used to load an LCM type self-powered barge. I have little experience with cranes and hope that I can get some suggestions here on what the best type of crane would be for this application.

Thanks,

Gregorio
 

Shenandoah

Well-Known Member
Joined
Nov 15, 2012
Messages
205
Location
Virginia
Perhaps a little more info would help. For instance, is your crane going to be dockside, or will it be on the barge? Also, the maximum height the crane needs to be to facilitate the loading, and do you want the cane to be mobile.

From what you're describing so far, that will be one huge crane. A crane that can lift 50 tons at a 60 foot radius sounds like a 3,000 ton crane if you do the math, (50 x 2000# x 60'). That's short tons @ 2,000 pounds a ton versus the 2,204.6 pounds in a metric tonne, if that matters.

Very basically, the way slewing cranes (rotating cranes) work can be broken down into a formula that uses foot pounds to determine the force and strength needed to move a load. A foot pound is a weight or force that is equal to one pound, one foot from the center of the rotating axis. That's the vertical axis running through the slewing gear, the slewing gear being the part of the crane that allows rotation. So a one pound load 60' from the rotating axis equals 60 foot pounds, and a 60 pound load 1' from the rotating axis equals 60 foot pounds, as well.

Now, if you want to lift 50 tons (100,000 pounds) at a 60' radius, the slewing gear will see 6,000,000 foot pounds (60 X 100,000) of force applied to the slewing gear. That's 3,000 tons of force. That's a BIG crane for a rotating crane. Additionally, the weight of the crane will have to be able to withstand that 3,000 tons of force trying to tip it over. It's a balancing act so you'll need a like-kind force on the opposite side of the slewing axis to balance he load.

Now, a gantry crane (two 'legs' supporting a load beam) is a different animal and can handle those big loads using different geometry and may be something you could consider if your crane had the ability to span the waterway where your barge is to be loaded. Put it on tracks and it's mobile...

All of the above is just food for thought, so any additional info you could provide will no doubt help with answering your question.
 

monoloco

Member
Joined
Jun 6, 2013
Messages
8
Location
Mexico
Thank you for the info Shenandoah, The crane will be on the bank of a river loading bundled logs onto a barge tied up at riverside from a bunk where they will be bundled to facilitate transfer to a log ship anchored at sea. The crane does not need to be mobile. The riverbank rises about 15' from the river so the crane should be above the level of the barge. As I indicated in my post, I have zero experience with cranes and I'm open to any ideas on the best way to get this done.
 

Shenandoah

Well-Known Member
Joined
Nov 15, 2012
Messages
205
Location
Virginia
How long are the logs you want to bundle and lift? A cane like the ones used to load containers can handle the weight you're looking to lift and can handle 53' long containers with ease. However, they don't rotate so the logs will need be accessible from the back of the crane in order to lift them.

Additionally, if you could lower your weight requirements per bundle the cost of your crane drops exponentially.

Just out of curiosity, do your ships have cranes that can lift a 50 ton load 60' out from the side of the ship?
 

monoloco

Member
Joined
Jun 6, 2013
Messages
8
Location
Mexico
The logs will be varying lengths to 40'
I am imagining that we will only need the crane to rotate 180º, we can design the loading facility to suit the crane.
I think so, the barge will be along side the ship so it will not need a great reach, I'm still researching the capacity of the ship's cranes. We could make the bundles smaller, but the objective is to load and transfer as quickly as possible to avoid demurrage fees. Thanks again for your help.
 

Shenandoah

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Joined
Nov 15, 2012
Messages
205
Location
Virginia
What weight would get us to a reasonable cost?

Impossible for me to answer that question. Find out the capacity of the offloading cranes on the ship first, (assuming they have them already). That could be your limiting factor because every crane on a ship or barge is limited to 50% of its' rated capacity by law. Once you know the max load the ship can handle then you will know the max load your bundles can be. And keep in mind you'll want to use around 80% of the cranes max capacity as a guide. Going over that could spell trouble in the long run.

Then start finding crane companies in your area to talk to. They should be able to place a cost for you on your requirements. And they should be able to help you with the regulations that you'll need to adhere to which could be many.

One thing you need to be clear on upfront is that there is NO fudging the laws of physics with a crane. They are unyielding. You need to build in the proper safety factors from the get-go. The entire system needs to be engineered correctly and that means loading and unloading both the barge and the ship.

As far as saving money goes, a good used crane may be the answer depending on how deep your pockets are, the amount of usage the crane will see, and what cranes are available both locally and shippable to your location.
 

monoloco

Member
Joined
Jun 6, 2013
Messages
8
Location
Mexico
We are in a remote roadless area so we will be sourcing the equipment on the US Gulf Coast and transporting it by barge to the site. We are just trying to figure out the most efficient way to do this and are open to any suggestions of other methods to accomplish the task. Thanks again for the education.
 

Buckethead

Senior Member
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Apr 4, 2007
Messages
1,055
Location
Waterfront
Occupation
Operator
As I indicated in my post, I have zero experience with cranes and I'm open to any ideas on the best way to get this done.

Call some crane rental companies. Tell them what you want to do. Have their representative come to your location if at all possible. They will recommend a machine and rigging for the job. Then rent their machine with operator. Not trying to be mean here, but if you have zero experience with cranes, you're not the person to be spec'ing out a crane. Definitely not for the numbers you're looking to pick, especially not on a riverbank where ground conditions could be very soft. Or a barge that is listing and heaving with every boat that goes by. Hope this helps.
 

monoloco

Member
Joined
Jun 6, 2013
Messages
8
Location
Mexico
Call some crane rental companies. Tell them what you want to do. Have their representative come to your location if at all possible. They will recommend a machine and rigging for the job. Then rent their machine with operator. Not trying to be mean here, but if you have zero experience with cranes, you're not the person to be spec'ing out a crane. Definitely not for the numbers you're looking to pick, especially not on a riverbank where ground conditions could be very soft. Or a barge that is listing and heaving with every boat that goes by. Hope this helps.
No offense taken, I realize I'm out of my element with this, that's why I'm here. The problem is that we are in a remote area of a third world country so it's not that easy to just call someone up, it costs several thousand dollars to fly someone in and pay for their time and expenses, so when we do that I would like to have a good understanding of just what the best way to approach this is, or if it's even feasible. Originally, we were going to use hydraulic excavators with grapples, a plan which we may return to, but we are looking to reduce the turnaround time on the barge, by loading bigger bundles. Thank you for your suggestions.
 

Shenandoah

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Joined
Nov 15, 2012
Messages
205
Location
Virginia
Monoloco, it seems your idea about using a crane to load the barge is on the right track assuming the logistics of getting the logs staged for the crane to handle them is on par with the throughput your crane can handle. What may be a good course of action is to scale back the load weight to something more doable for your situation.

Remember, a crane needs a solid foundation and that means a massive effort may be required to make the dockside suitable to allow for a stable base. Something else you'll want to consider is that a crane that swivels requires it to be within 1% of level at all times. So if your crane base creeped over time due to sagging soils, et al, and your crane no longer remained level, your operations would be in jeopardy due to a now unsafe condition. In other words, your crane may require a very expensive pier to be built.

Going from hydraulic excavators with grapples to a massive crane is quite a leap. I can understand the desire to increase throughput, but the costs associated may be insurmountable given your remote location. Additionally, creating an infrastructure where one component (the big crane) can have extended downtime causing the entire operation to cease functioning needs to be considered.

There are many cranes out there that would be good candidates to outwork hydraulic excavators with grapples for your purposes and not require such a dedicated foundation. If you have a good indication of the throughput those hydraulic excavators with grapples can produce perhaps a simple doubling of the throughput by a single crane would be profitable without the huge front end financial requirements.

It would seem to me a good sized mobile lattice crane would work and give you the ability to get parts as needed. The more you stay with standardized equipment the easier the logistics of keeping the operation running should be.
 

Blmreject

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Joined
Nov 28, 2011
Messages
74
Location
Northwest, oregon
Occupation
mobile crane op IUOE Local 701
Perhaps a little more info would help. For instance, is your crane going to be dockside, or will it be on the barge? Also, the maximum height the crane needs to be to facilitate the loading, and do you want the cane to be mobile.

From what you're describing so far, that will be one huge crane. A crane that can lift 50 tons at a 60 foot radius sounds like a 3,000 ton crane if you do the math, (50 x 2000# x 60'). That's short tons @ 2,000 pounds a ton versus the 2,204.6 pounds in a metric tonne, if that matters.

Very basically, the way slewing cranes (rotating cranes) work can be broken down into a formula that uses foot pounds to determine the force and strength needed to move a load. A foot pound is a weight or force that is equal to one pound, one foot from the center of the rotating axis. That's the vertical axis running through the slewing gear, the slewing gear being the part of the crane that allows rotation. So a one pound load 60' from the rotating axis equals 60 foot pounds, and a 60 pound load 1' from the rotating axis equals 60 foot pounds, as well.

Now, if you want to lift 50 tons (100,000 pounds) at a 60' radius, the slewing gear will see 6,000,000 foot pounds (60 X 100,000) of force applied to the slewing gear. That's 3,000 tons of force. That's a BIG crane for a rotating crane. Additionally, the weight of the crane will have to be able to withstand that 3,000 tons of force trying to tip it over. It's a balancing act so you'll need a like-kind force on the opposite side of the slewing axis to balance he load.

Now, a gantry crane (two 'legs' supporting a load beam) is a different animal and can handle those big loads using different geometry and may be something you could consider if your crane had the ability to span the waterway where your barge is to be loaded. Put it on tracks and it's mobile...

All of the above is just food for thought, so any additional info you could provide will no doubt help with answering your question.

My 285T crawler can gross 112k @ 65 feet with 154 foot of boom. I'm not trying to call you out or anything but that math doesn't really seem to work.
 

John C.

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Joined
Jun 11, 2007
Messages
12,865
Location
Northwest
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Machinery & Equipment Appraiser
I believe Mr. Shenandoah is confusing lifting capability, as in power to lift a load or line pull, with the stability factors of a crane. The rotating joint won't see that weight because there will be counterweight on the back side to balance out what you are lifting. The power issue is also solved by using multipart blocks. As I recall you divide the load by the parts of line till you get to the line pull of the drum. So if you are picking 100,000 pounds with a six part block you would only need 16,666 pounds of line pull.

Mr. Gregorio, you would do well with a crane to load a barge. I've seen plenty of 150, 250 and 300 ton crawler cranes in Alaska doing what you are requesting. Contact a crane manufacture to find someone who can engineer what you actually need and work from there. Manufacturers you might look up include Link-Belt, Manitowoc, Lieberr, Kobelco, Demag and I'm sure there are others.

Good Luck!
 

IHguy

Member
Joined
Jun 7, 2012
Messages
10
Location
Chicago
Occupation
consultant
Dear td25c.,
Greetings,
At your convenience, could you please contact me regarding your LaCrosse lowboy trailer?
I am looking at one , 1930's/ 1940's vintage.
Can you give any advice?
Durability?
Thank you. Marty c. # 773-490-9747 martymersch @ comcast. net
 
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