Floating Bridge out again!!!

[VicS]

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/documents/1335-1335-Floating-Bridge-Technical-Spec-redacted.pdf

 

[prv]

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/documents/1335-1335-Floating-Bridge-Technical-Spec-redacted.pdf

Thanks, that looks quite interesting.

Pete

 

[JumbleDuck]

ITYWF that it is all hydraulically operated

Even easier then. Something along the lines of a Citroën suspension sphere would provide both springing and damping to deal with the sudden loading.

 

[jbweston]

Knicker elastic should do the trick. Could double it up to add a safety factor.

 

[lpdsn]

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.

 

[prv]

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

 

[LadyInBed]

How the hell does one ' snap ' one of those chains ?!

Non certified chain!

 

[[70521]]

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?

 

[Greenheart]

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?

 

[JumbleDuck]

I wonder what it would cost, to build an exact replica of the old floating bridge?

Has the old one been cut up yet?

 

[dom]

Has the old one been cut up yet?

Can’t recall it being in P’mouth where it was moored recently but cld be wrong.

What were you thinking, cut the new one up instead? :ambivalence:

 

[VicS]

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?[/quote}

It was specifically designed for the crossing between Cowes and East Cowes. see my earlier link.

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

FB5 was operating apparently without difficulty, for a period after the new breakwater was completed

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?

 

[AndrewL]

There are two interesting articles in the local news. The first shows how the total cost is now at £6.4M, about double the original estimate.

https://onthewight.com/floating-bridge-costs-rise-to-a-staggering-6-4m/

The second article is suggesting that there are now proposals to scrap it, or sell it. The article mentions that it could be used to replace the Windermere Ferry, although I cannot think how they would get it there. It came to Cowes by sea, it's surely too big for overland transport.

https://www.iwcp.co.uk/news/1721083...-sent-to-cumbria-if-repairs-arent-successful/

It still requires a tug to push it laterally during the ebb on spring tides, to ensure it keeps on the rhumb line between the two slipways. It is also very frequently out of service, which requires a replacement passenger ferry. Both of which the council pay for. It will never be profitable, unlike the previous ferry which returned a healthy annual profit of around £150,000.

 

[sarabande]

Shirley the time has come for the burghers of the Island to call for a public enquiry. Incompetence of management oozes from every pore of the project. Oh, and a judicial review of the reasons why the Council will not release cost details and committee minutes.

 

[dom]

Agreed, it's time for either honesty or inquiry:

"Publicity is justly commended as a remedy for social and industrial diseases. Sunlight is said to be the best of disinfectants; electric light the most efficient policeman."
​

US Supreme Court Justice Louis D Brandeis​

 

[chrishscorp]

Has the old one been cut up yet?

FB5 was still tied up in Portsmouth Hbr 2 weeks ago, quietly hoping to be pressed back into service no doubt.... I seem to recollect there was another barge along side it.

 

[chrishscorp]

The second article is suggesting that there are now proposals to scrap it, or sell it. The article mentions that it could be used to replace the Windermere Ferry, although I cannot think how they would get it there. It came to Cowes by sea, it's surely too big for overland transport.

https://www.iwcp.co.uk/news/1721083...-sent-to-cumbria-if-repairs-arent-successful/

Chop it into 4 bits and send it up on a lorry with a couple of packs of welding rods

 

[JumbleDuck]

FB5 was still tied up in Portsmouth Hbr 2 weeks ago, quietly hoping to be pressed back into service no doubt.... I seem to recollect there was another barge along side it.

I think it was VicS who said that the chain layout has been changed for FB6, but it surely would not be impossible to revert to the old system.

 

[awol]

Shirley the time has come for the burghers of the Island to call for a public enquiry. Incompetence of management oozes from every pore of the project. Oh, and a judicial review of the reasons why the Council will not release cost details and committee minutes.

Careful what you wish for! The review into the Edinburgh tram fiasco has hit £7M, is still rising and is likely to keep lawyers in employment on the matters arising for decades to come.

 

[JumbleDuck]

Careful what you wish for! The review into the Edinburgh tram fiasco has hit £7M, is still rising and is likely to keep lawyers in employment on the matters arising for decades to come.

On the bright side, the Edinburgh Tram project will keep business schools in case studies for decades.