Sometime a lot of knowledge must got lost somewhere, somehow. There are many examples of ancient engineering and work that can't be explained and are even complicated to be redone today. How they made all the calculations just with stone board and chisel .
Heavy lifting can be performed at different heights, depending on the structure or load to be lifted (dimensions, shape, weight…), worksite configuration, and purpose of the operation. A strand jack is a type of linear winch system used for pulling heavy loads from above. They are widely used in the heavy construction industry, especially for bridges, ports, and large-scale plant maintenance projects. Lifting capacities vary depending on the models used ….. To start lifting the bottom clamp releases the wire and the top clamp is pushed up hydraulically whilst gripping the wire, which thus also moves up. Then the bottom clamp grips the wire, the top clamp is released and the hydraulic cylinder is retracted.
It's ok to include a narrative of what we are watching. To explain just a little bit of what is happening and how it works. Then it will add even more credibility to your innovations....
So basically this is how it goes, you have 3 jacks in each strand jack, the main jack which does the lifting, and 2 smaller jacks that lock or unlock the wedges on top and bottom parts of the strand jack. If you want to lift a load, the wedges on the top part are tightened to the strands using the top anchor jack. After that the main jack is extended and the load is lifted for the stroke distance of main jack. After the stroke is done, the main jack needs to be retracted without lowering the load, so while both top and bottom anchors are closed, the main cylinder is lowered for about 20mm to transfer the load from top anchor to bottom anchor. Then it is safe to open top anchor wedges using top cylinder. That way the strands are cleared and the main cylinder can be retracted with the load suspended by bottom anchor. Then top anchor is closed and main cylinder can be extended again to continue lifting! There is another similar procedure to lower the load. I operated these systems in 8 occasions to lift loads up to 400t and they are awesome and very safe to operate if you know what you are doing.
@@firasetaiwi8813 In case several strand jacks are operated then a SCC (Smart cylinder control) is necessary to make a synchronous lifting with only a few milimeters difference between strand jacks.
Disappointed with the jobs use are doing all over the world and there is very few videos to watch. Can someone change this please as i love seeing the actual job being done
Hi Mark, We love videos too! There is a lot that goes in to making these videos, including approvals from multiple parties before we can share them publicly. We will continue to create and release as many quality videos as we can as we love to share the great work our teams do!
Simple and robust, we need more of it these days. Nice engineering!
Question: how did " they " move the " trillithon " at balbeck Lebanon?
Or other mega ton loads of history.
Thanks.
Great question! Unfortunately we do not have an answer for that one. We can rule out the SPMT!
Sometime a lot of knowledge must got lost somewhere, somehow. There are many examples of ancient engineering and work that can't be explained and are even complicated to be redone today. How they made all the calculations just with stone board and chisel .
Why not on the first job they used this! The lifting of the kursk?
Wow, fabulous, simple explanation. Awesome, thank you
Are these Enerpac strand jacks that you use or do you make your own?
It is an elegant solution
Are these used to increase the capacity of a crane?
Heavy lifting can be performed at different heights, depending on the structure or load to be lifted (dimensions, shape, weight…), worksite configuration, and purpose of the operation.
A strand jack is a type of linear winch system used for pulling heavy loads from above. They are widely used in the heavy construction industry, especially for bridges, ports, and large-scale plant maintenance projects. Lifting capacities vary depending on the models used …..
To start lifting the bottom clamp releases the wire and the top clamp is pushed up hydraulically whilst gripping the wire, which thus also moves up. Then the bottom clamp grips the wire, the top clamp is released and the hydraulic cylinder is retracted.
It's ok to include a narrative of what we are watching. To explain just a little bit of what is happening and how it works. Then it will add even more credibility to your innovations....
Thank you for the feedback!
So basically this is how it goes, you have 3 jacks in each strand jack, the main jack which does the lifting, and 2 smaller jacks that lock or unlock the wedges on top and bottom parts of the strand jack.
If you want to lift a load, the wedges on the top part are tightened to the strands using the top anchor jack. After that the main jack is extended and the load is lifted for the stroke distance of main jack. After the stroke is done, the main jack needs to be retracted without lowering the load, so while both top and bottom anchors are closed, the main cylinder is lowered for about 20mm to transfer the load from top anchor to bottom anchor. Then it is safe to open top anchor wedges using top cylinder. That way the strands are cleared and the main cylinder can be retracted with the load suspended by bottom anchor.
Then top anchor is closed and main cylinder can be extended again to continue lifting!
There is another similar procedure to lower the load. I operated these systems in 8 occasions to lift loads up to 400t and they are awesome and very safe to operate if you know what you are doing.
@@firasetaiwi8813 thanks, what you explained wasn't so evident in the video presentation. But I understand now! :)
@@firasetaiwi8813 In case several strand jacks are operated then a SCC (Smart cylinder control) is necessary to make a synchronous lifting with only a few milimeters difference between strand jacks.
@@jorgereis6228 yes definitely.
OMG Bertha. What a CF of a project. Thank you Mammoet for rescuing this stupid city from their incompetence.
Disappointed with the jobs use are doing all over the world and there is very few videos to watch. Can someone change this please as i love seeing the actual job being done
Hi Mark, We love videos too! There is a lot that goes in to making these videos, including approvals from multiple parties before we can share them publicly. We will continue to create and release as many quality videos as we can as we love to share the great work our teams do!