Free 186 More Best Homemade Tools eBook:  
Get 2,000+ tool plans, full site access, and more.

User Tag List

Results 1 to 6 of 6

Thread: Crane recovery fail - GIF

  1. #1
    Content Editor
    Supporting Member
    Altair's Avatar
    Join Date
    Aug 2013
    Posts
    11,730
    Thanks
    1,353
    Thanked 29,267 Times in 9,726 Posts

    Crane recovery fail - GIF


    186 More Best Homemade Tools eBook

  2. The Following 3 Users Say Thank You to Altair For This Useful Post:

    carloski (Mar 2, 2022), Ralphxyz (Mar 2, 2022), Rangi (Mar 9, 2022)

  3. #2
    WmRMeyers's Avatar
    Join Date
    Dec 2014
    Posts
    883
    Thanks
    402
    Thanked 366 Times in 252 Posts

    WmRMeyers's Tools
    THATS NOT HOW IT WAS SUPPOSED TO WORK!

    Wonder just how deep the water is there? Also, how much other stuff is sitting there under it?

    2000 Tool Plans

  4. #3
    Supporting Member NortonDommi's Avatar
    Join Date
    Jul 2014
    Location
    North Island, New Zealand.
    Posts
    990
    Thanks
    1,800
    Thanked 524 Times in 315 Posts

    NortonDommi's Tools
    Quote Originally Posted by WmRMeyers View Post
    THATS NOT HOW IT WAS SUPPOSED TO WORK!

    Wonder just how deep the water is there? Also, how much other stuff is sitting there under it?
    Yes, I'm wondering if the crane or its rope was hooked on something.

  5. #4
    Supporting Member hemmjo's Avatar
    Join Date
    Feb 2017
    Posts
    2,542
    Thanks
    224
    Thanked 1,446 Times in 820 Posts

    hemmjo's Tools
    My opinion is the straps were probably inadequate, old, worn AND they were improperly secured to the crane. You cannot use straps where they are subjected to abrasion or damage from objects that impose any kind of concentrated force. The head of a bolt, of the rough edge of a casting, or the corner of a beam, etc. will create a very concentrated point load causing the strap to fail at that point.

    The straps were probably attached by a diver with poor visibility and perhaps improper knowledge of rigging for a lift like that.

    Below are 4 frames showing that the straps we improperly attached to the load.

    Notice the first strap broke where it was in contact with the structure of the truck.
    Should have used a proper chain attached to the truck then a proper shackle to the straps.
    Crane recovery fail - GIF-screen-shot-2022-03-02-6.34.57-pm.png Crane recovery fail - GIF-screen-shot-2022-03-02-6.35.13-pm.png

    After the first strap book, there is no way the second would hold the load by itself.
    But you can see that even this one failed where it was in contact with the structure of the truck.

    Name:  Screen Shot 2022-03-02 at 6.36.45 PM.png
Views: 2201
Size:  68.3 KB Crane recovery fail - GIF-screen-shot-2022-03-02-6.36.56-pm.png

  6. The Following 6 Users Say Thank You to hemmjo For This Useful Post:

    Inflight (Mar 2, 2022), KustomsbyKent (Mar 2, 2022), NortonDommi (Mar 2, 2022), Rangi (Mar 9, 2022), Toolmaker51 (Mar 2, 2022), WorkerB (Mar 3, 2022)

  7. #5
    Supporting Member Frank S's Avatar
    Join Date
    Aug 2015
    Location
    Peacock TX
    Posts
    11,179
    Thanks
    1,974
    Thanked 8,766 Times in 4,195 Posts

    Frank S's Tools
    Quote Originally Posted by hemmjo View Post
    My opinion is the straps were probably inadequate, old, worn AND they were improperly secured to the crane. You cannot use straps where they are subjected to abrasion or damage from objects that impose any kind of concentrated force. The head of a bolt, of the rough edge of a casting, or the corner of a beam, etc. will create a very concentrated point load causing the strap to fail at that point.

    The straps were probably attached by a diver with poor visibility and perhaps improper knowledge of rigging for a lift like that.

    Below are 4 frames showing that the straps we improperly attached to the load.

    Notice the first strap broke where it was in contact with the structure of the truck.
    Should have used a proper chain attached to the truck then a proper shackle to the straps.
    Click image for larger version. 

Name:	Screen Shot 2022-03-02 at 6.34.57 PM.png 
Views:	117 
Size:	59.2 KB 
ID:	42091 Click image for larger version. 

Name:	Screen Shot 2022-03-02 at 6.35.13 PM.png 
Views:	54 
Size:	55.5 KB 
ID:	42092

    After the first strap book, there is no way the second would hold the load by itself.
    But you can see that even this one failed where it was in contact with the structure of the truck.

    Name:  Screen Shot 2022-03-02 at 6.36.45 PM.png
Views: 2201
Size:  68.3 KB Click image for larger version. 

Name:	Screen Shot 2022-03-02 at 6.36.56 PM.png 
Views:	63 
Size:	65.8 KB 
ID:	42094
    I think you just about summed it up with the comment about poor visibility. and straps Recovery divers in general have a fair amount of rigging knowledge. since we don't have any footage of the dives showing them in the rigging process, I personally wouldn't be too quick on condemning either the diver or the straps. I would be more inclined to fault the breaking surface inspection if there even was one. It would be very dangerous to even consider re rigging at the surface even with a second crane on location. However being able to point out better or more rigging points while the crane was still mostly submerged allowing the density to the water to support part of the weight. then lowering it back to the bottom and either re rigging or adding more lifting straps slings cables ETC. 4 points are better than 3, 5 or 6 are even better.
    Plus, for all we know the first strap to fail may have been attached to a tie down eye, and that may have been what failed first creating the domino effect. Tie down eyes are not strong enough to support the full weight of a crane.
    Or between the time the underwater rigging was done and the actual lift being preformed currents could have shifted the slack straps to cause them to be hung up where they were not intended
    Last edited by Frank S; Mar 2, 2022 at 05:59 PM.
    Never try to tell me it can't be done
    When I have to paint I use KBS products

  8. #6
    Supporting Member Moby Duck's Avatar
    Join Date
    Jan 2016
    Posts
    387
    Thanks
    1,215
    Thanked 196 Times in 124 Posts

    Moby Duck's Tools
    This is a Royal Navy Dockyard so it is very unlikely that the lifting straps were in poor condition. They are subjected to regular inspections as well as visual inspections before use. It is unlikely that the crane had lifting points underneath, but it may have had towing eyes, not rated for such a lift. Whatever happened, nobody got hurt so it wasn’t all bad.



    186 More Best Homemade Tools eBook

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •