Page 3 of 6 FirstFirst 123456 LastLast
Results 21 to 30 of 59
  1. #21
    Join Date
    Jul 2002
    Location
    Home: Kent. Boat: Chichester
    Posts
    42,264

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by prv View Post
    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
    ITYWF that it is all hydraulically operated

    If you have a moment or two to spare you can read the tech spec at https://www.iow.gov.uk/azservices/do...c-redacted.pdf
    Last edited by VicS; 30-10-18 at 02:42.

  2. #22
    Join Date
    Nov 2009
    Location
    Southampton
    Posts
    34,592

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by VicS View Post
    ITYWF that it is all hydraulically operated

    If you have a moment or two to spare you can read the tech spec at https://www.iow.gov.uk/azservices/do...c-redacted.pdf
    Thanks, that looks quite interesting.

    Pete

  3. #23
    Join Date
    Aug 2013
    Location
    SW Scotland
    Posts
    17,884

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by VicS View Post
    ITYWF that it is all hydraulically operated
    Even easier then. Something along the lines of a CitroŽn suspension sphere would provide both springing and damping to deal with the sudden loading.
    "Seamen are always wanting to do things the proper way; and I like to do them my way."

  4. #24
    Join Date
    Jun 2005
    Location
    Me: Ashby-de-la-Zouch. Boat: Sweden
    Posts
    534

    Default Re: Floating Bridge out again!!!

    Knicker elastic should do the trick. Could double it up to add a safety factor.
    Julian of Penguin
    Penguin's Progress

  5. #25
    Join Date
    Apr 2009
    Posts
    5,213

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by prv View Post
    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
    Would it not just require the same sort of algorithm a lift uses to come gently to a stop in the right place.

    Although I did live for a while in a flat in a Soviet-era housing estate in Poland. The lift there was only either stopped or travelling at a constant speed. Got used to it after the first few days.

  6. #26
    Join Date
    Nov 2009
    Location
    Southampton
    Posts
    34,592

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by lpdsn View Post
    Would it not just require the same sort of algorithm a lift uses to come gently to a stop in the right place.
    I don't really know much about lifts but presumably they (at least simple ones) have a switch that triggers a little way before the desired position, to signal that it's time to slow down. The doors on each floor don't really move around much

    For the ferry I was assuming that the point where tension comes on the wire would vary a bit depending on the state of the tide, loading of the boat, angle it came onto the ramp, etc. I was envisaging doing it by winding in initially with a low torque setting, then when the motor stops on overtorque, immediately restarting with the full torque necessary to lift the ramp. The stop and start would be within a few milliseconds and not noticeable at human scale, but enough to mitigate the jerk. The restart could be ramped if necessary to smooth things out further.

    None of this is applicable since the ferry is in fact hydraulically operated, but no doubt there's some mechanical hydraulic equivalent.

    Pete

  7. #27
    Join Date
    Sep 2001
    Location
    Me - Zumerzet Boat - Wareham
    Posts
    11,366

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by Seajet View Post
    How the hell does one ' snap ' one of those chains ?!
    Non certified chain!
    MontyMariner.co.uk
    Facilitated by AWESEM WP Agency

  8. #28
    Join Date
    Aug 2011
    Location
    On the Celtic Fringe
    Posts
    12,703

    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
    How does it land? Last time I was in Cowes there was a lot of birds about, has a safety assessment been done? Will you be handing out free ear defenders to the the entire population of Cowes for life. Will there be a "Green Funnel" variety?
    Cynical Scottish almost retired engineer.

  9. #29
    Join Date
    Dec 2010
    Posts
    8,293

    Default Re: Floating Bridge out again!!!

    I wonder what it would cost, to build an exact replica of the old floating bridge? Whatever its shortcomings, it usually operated.

    Maybe this present incarnation which appears not to have been carefully measured or specified for use at Cowes, could be sold to another river/harbour mouth location, to recoup some capital to make a dent in the cost of a replica of the old one?

    Or has the flow in the Medina changed since the breakwater was built, such that the old bridge wouldn't be effective either?

    Hopeless though the new bridge seems to have been, its failure can't haven't profited anybody much. Is it likely that any of us could have diagnosed the errors in the design, ahead of testing in situ?

  10. #30
    Join Date
    Aug 2013
    Location
    SW Scotland
    Posts
    17,884

    Default Re: Floating Bridge out again!!!

    Quote Originally Posted by dancrane View Post
    I wonder what it would cost, to build an exact replica of the old floating bridge?
    Has the old one been cut up yet?
    "Seamen are always wanting to do things the proper way; and I like to do them my way."

Page 3 of 6 FirstFirst 123456 LastLast

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
  •  

Latest YBW News

Find Boats For Sale

to
to