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  1. #11
    Join Date
    Jul 2006
    Location
    Emsworth Hants
    Posts
    11,873

    Default Re: Floating Bridge out again!!!

    I do wish they would stop calling it a floating bridge it is a ferry.

  2. #12
    Join Date
    Dec 2003
    Posts
    4,792

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by KellysEye View Post
    I do wish they would stop calling it a floating bridge it is a ferry.
    Id call it something else,

    But this is a public forum!

  3. #13
    Join Date
    Oct 2001
    Location
    Surrey & boat in Dorset. Both have pubs
    Posts
    3,340

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by KellysEye View Post
    I do wish they would stop calling it a floating bridge it is a ferry.
    How can it be called a ferry when it is not ferrying, that seems to be most of the time?

  4. #14
    Join Date
    Nov 2009
    Location
    Southampton
    Posts
    34,600

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by Seajet View Post
    How the hell does one ' snap ' one of those chains ?!
    To be clear, it's not one of the main chains across the river that has snapped, but one of the ones holding up the ramp.

    I still don't know how they managed it, but I'm sure the ramp supports are a lot lighter than the main chains.

    Pete

  5. #15
    Join Date
    Jul 2002
    Location
    Home: Kent. Boat: Chichester
    Posts
    42,279

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by prv View Post
    To be clear, it's not one of the main chains across the river that has snapped, but one of the ones holding up the ramp.

    I still don't know how they managed it, but I'm sure the ramp supports are a lot lighter than the main chains.

    Pete
    This is the second time one of the ramp lifting chains has broken. Last time they were all replaced partly by wire cables with, afaik, only the end section remaining as chain. I believe it is actually the wire cable section that has failed this time, at least that was what was said in one of the first reports.

    I suspect the problem is the snatch loads that the chains/ cables are subjected to.

    When the ramp is raised the slack in the chains is wound in and then without pausing the ramp is lifted. One might expect a system where once the slack has been taken up it pauses and then restarts with "a soft start". Think how the crane lifting your boat operates. Firstly all the slack in the slings etc is taken up then the actual lift starts gently........ at least it does if you have a good crane operator.

    Also if you watch as they approach the shore. they lower the ramp, I guess so that they can see from the stupidly placed central control cabin. When the lowering stops with the ramp fully extended horizontally it does so abruptly. If you watch you can see it " bounce" on the lifting chains.

  6. #16
    Join Date
    Sep 2010
    Location
    West Sussex / Hants
    Posts
    27,569

    Default Re: Floating Bridge out again!!!

    All you need is a good run-up and a ski-ramp, forget the chat about tunnels or bridges !

    https://www.flickr.com/photos/73614187@N03/43292843314
    Anderson 22 Owners Association - For info please ask here or PM me.

  7. #17
    Join Date
    Aug 2013
    Location
    SW Scotland
    Posts
    17,890

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by Seajet View Post
    All you need is a good run-up and a ski-ramp, forget the chat about tunnels or bridges !

    https://www.flickr.com/photos/73614187@N03/43292843314
    Right way up? What a wuss. This is how it's done:



    Geek trivia: That was the first movie stunt to be checked and set up using mathematical modelling beforehand, rather than "that looks about right"
    "Seamen are always wanting to do things the proper way; and I like to do them my way."

  8. #18
    Join Date
    Sep 2010
    Location
    West Sussex / Hants
    Posts
    27,569

    Default Re: Floating Bridge out again!!!

    I'm thinking Mr J Daniels may have been involved in the calculations, if not he should have been.

    Anything would be better than the present setup, apparently designed by Homer Simpson.
    Anderson 22 Owners Association - For info please ask here or PM me.

  9. #19
    Join Date
    Mar 2006
    Location
    Surrey
    Posts
    8,284

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by VicS View Post
    This is the second time one of the ramp lifting chains has broken. Last time they were all replaced partly by wire cables with, afaik, only the end section remaining as chain. I believe it is actually the wire cable section that has failed this time, at least that was what was said in one of the first reports.

    I suspect the problem is the snatch loads that the chains/ cables are subjected to.

    When the ramp is raised the slack in the chains is wound in and then without pausing the ramp is lifted. One might expect a system where once the slack has been taken up it pauses and then restarts with "a soft start". Think how the crane lifting your boat operates. Firstly all the slack in the slings etc is taken up then the actual lift starts gently........ at least it does if you have a good crane operator.

    Also if you watch as they approach the shore. they lower the ramp, I guess so that they can see from the stupidly placed central control cabin. When the lowering stops with the ramp fully extended horizontally it does so abruptly. If you watch you can see it " bounce" on the lifting chains.
    I believe that one of the reasons for changing over to partial wire cables was that there were complaints from the neighbours about the noise made by the original chains running through the 'crane' section when the ramp was lowered or raised particularly during late night operation.
    Gosport NCI - Call us on Ch 65 for a radio check if passing.

  10. #20
    Join Date
    Nov 2009
    Location
    Southampton
    Posts
    34,600

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by VicS View Post
    I suspect the problem is the snatch loads that the chains/ cables are subjected to.

    When the ramp is raised the slack in the chains is wound in and then without pausing the ramp is lifted. One might expect a system where once the slack has been taken up it pauses and then restarts with "a soft start".
    A two-stage takeup like that would certainly be kinder on the gear, but I'd have hoped that the margin of safety would be enough not to need it...

    Assuming the motor isn't being directly controlled by a human being beyond pressing a "ramp up" button, taking in the slack then pausing at the right point and restarting softly might require slightly more sophisticated control gear than initially fitted. But there is certainly kit out there that can do it; a few months ago at work I encountered an Elmo Golden Oboe (their product names are notorious ) that I think could be programmed that way.

    Pete

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