Forum menu
I didn't say ' way off course'.
My wording was 'way off-line'; there is a difference.
I stand by my comments.
This pic really highlights the scale of what happened
"I didn’t say ‘ way off course’.
My wording was ‘way off-line’; there is a difference.
I stand by my comments."
They weren't way off-line before the blackout, you can see their track on Marine Traffic.
Once they lost power they would of known they were heading off track, the radars and nav systems are some of the last things to go but they wouldn't of had enough power to operate the rudder. Not a lot they could of done apart from drop an anchor.
As for pier protection, can anyone provide examples on bridges which span major shipping channels?
forth road bridge;
tay road bridge;
https://www.tayroadbridge.co.uk/about/history/past-projects
and I’m pretty sure there is comparable protection on both the Severn bridge and the Dartford crossing too.
From elsewhere on the Internet:
"the ship lost power twice, officials are speculating a fire on board."
This is, of course, completely unconfirmed.
Someone on the deck must have seen they were way off-line in a shipping channel
They weren't.... and then they were, but were basically powerless to do anything about it.
(also they wouldn't go through the middle of the span as they need to leave the Fort Carroll island to port so would probably already be on a course closer to the starboard pier)
Holy shit.
I won't speculate on the cause, there are plenty of seemingly innocuous things that can shut down an engine but if you're blacked out you're at the mercy of the currents. Looks like a genuine case of wrong time and place.
I'm more concerned about the folk on the bridge tbh.
frankconway
There is nothing unusual about the bridge design; comments about ‘flimsy supports’ lack engineering credibility.
Yeah, there's "flimsy" and there's "collapsed when hit by several million tons of ship"
I'm looking forward to the the whole "Today I am expert in (but not limited to) Harbour piloting, maritime navigation, and multi-span bridge engineering" vibe that this thread will descend into in short order. Don't let me down.
I can claim 2 of those.
can't believe someone just got themselves out of the water and refused help.
Fingers crossed for others, but at 9deg it's sadly unlikely there will be any further survivors.
Horrible all round.
It will be a massive task to even recover the bodies.
As for pier protection, can anyone provide examples on bridges which span major shipping channels?
Forth yes, is there a major port on the Tay upriver of the bridge? It'd be interesting to see what calculation they used to size them because I wonder how feasible it would be to stop a container ship that size. Because if you made it strong enough then the ship sinks and you end up with even worse disruption as/if it blocks the channel anyway.
And from watching American politics, infrastructure funding seems very disjointed with projects being added as amendments to other legislation to get votes.
Øresund Bridge
It will be a massive task to even recover the bodies.
Possibly considered a bit distasteful at this point so close to the event but I'd say basically impossible unless they get very lucky. And possibly worse - given the time pressure they will be under to get the wreckage of the bridge clear and the shipping lane reopened , the chance of the 'final resting place' being given any sort of respect is slim to none. Bodies might be 'recovered' amid the clearing maybe but I'd sure as hell not want to be present as a family member when it happened.
Because if you made it strong enough then the ship sinks and you end up with even worse disruption as/if it blocks the channel anyway.
Not necessarily, ships can t-bone each other and still sail themselves to dry dock.
And I'm not sure about worse disruption, in case you missed it there's an entire bridge blocking the channel.
The main navigation channel is pretty narrow.
It shouldn't take too long to open that back up, however, if that would be enough to make be considered safe enough to use, with all the other stuff going on, is another question.
It's going to be an interesting job getting the ship free of the wreckage before you even start clearing the channel.
I wonder how feasible it would be to stop a container ship that size
The islands they build are rarely put together to flat out stop a ship of that size, and indeed if there were a direct collision it would still be pretty bad I'm sure. But they do try and build them strong enough that they can deflect such a vessel and leave the structure largely in tact.
How often they actually get put to the test though, I don't know...
I’m looking forward to the the whole “Today I am expert in (but not limited to) Harbour piloting, maritime navigation, and multi-span bridge engineering” vibe that this thread will descend into in short order. Don’t let me down.
In that case I'd recommend IFLS's feeds on Facebook. We're going to need more Bacofoil.
Christ, those poor folk seeing that coming towards them on the bridge, and I feel for the pilots who will be native to the water, know the route/tidal currents extremely well and do this job many times a week - must surely be a propulsion/engine/rudder failure.
Not necessarily, ships can t-bone each other and still sail themselves to dry dock.
In engineering terms "not necessarily" gets into the realms of business cases though. Civils isn't my area but I imagine it goes something similar to my industry:
New stuff is built to codes, standards and best available technology / best industry practice.
Old stuff remains as it is unless either there's a mandatory (not necessarily legislative, might jus t be forced by insurance, or your safety case is no longer valid as you stated that something never happens) change required e.g. after Buncefield I was busy for years re-designing the instrumentation on storage tanks. Or someone develops a business case that says £.. million will save you x*£..million on a 1 in <x chance.
In this case I'm guessing someone figures the risk of a collision was low enough.
Selling preventative engineering is hard work, a few tens of millions on this would not have won any votes compared to building a school or fixing potholes.
And I’m not sure about worse disruption, in case you missed it there’s an entire bridge blocking the channel.
Yup, but you'd have exactly the same problem (probably harder to solve) if it was a ship sunk in the channel.
I can claim 2 of those.
I can claim 1 but without any knowledge of protecting bridges against ship collisions. It would appear that protection to the Forth bridges was considered well after the original construction, I would imagine due to increases in ship size.
Because if you made it strong enough then the ship sinks and you end up with even worse disruption as/if it blocks the channel anyway.
I would go with the ship sinking any day rather than a major bridge collapse. If the protective caissons around bridge piers are well shaped it would only be a glancing blow anyway.
"As for pier protection, can anyone provide examples on bridges which span major shipping channels?"
Um... The cable bridge about 50m away from the bridge that was hit?
there's cost/benefit on any engineering. Lets say adding some islands big enough to stop a massive container ship costs $1bn per bridge (guessing, obviously). And there's maybe 1000 bridges that need such protection - thats a trillion dollars - if bridges last 100 years on average, that's 10bn dollars per year. If 20 people died last night, its terrible, but when was the last time such an event occured? a decade ago? if so the cost of putting protection up would be $5bn per person.
even if the numbers are way way different what I'm suggesting - $100m to build an island, only 100 bridges worth protecting, one falls over ever year, you'd still be looking at $5mm per person which has got to be only *just* breaking even.
"I can claim 1 but without any knowledge of protecting bridges against ship collisions"
I can claim all 3 of them.
Forth yes, is there a major port on the Tay upriver of the bridge?
Perth, not major in any way. Boats are still big enough you would not want them bumping into any transport bridges.
I am fairly sure (because I remember both event) the forth protection was put in in the 90 on privatisation of the rosyth docks. I assume to allow civilian shipping, coincided roughly with the ferry terminal.
"there’s cost/benefit on any engineering."
True, but don't forget about the cost of rebuilding the bridge, the cost of the obstructed maritime channel, and the cost of increased congestion on I95 etc (which in my amateur observations are rammed 20 hours a day).
you’d still be looking at $5mm per person which has got to be only *just* breaking even.
Its not just per person though but the additional costs of a)removing the wreckage b)rebuilding it and c)the disruption caused during that time to normal traffic flows in the country.
you’d still be looking at $5mm per person which has got to be only *just* breaking even.
Obviously we're not crude enough to actually put a number on it like that. But if you work backwards it's usually ranked:
personal injury - £100k lost profit
on site fatality - £1million
multiple fatalities or one member of the public - £10 million
Varies between industries as it's linked to reputational damage, so nuclear will rank it much higher because 1 death in a nuclear facility is news for the next couple of decades.
That Tay Bridge project for example was ~£30million in todays money.
Yup, but you’d have exactly the same problem (probably harder to solve) if it was a ship sunk in the channel.
"Not necessarily" was in reply to the notion that it would sink a ship. They're surprisingly resilient, even loaded up the way that one was.
but when was the last time such an event occured? a decade ago?
Barely a month ago when a barge hit the Lixinsha Bridge in Guangzhou.
So it appears there was an international symposium on ship collisions in 1998
Ships and barges hit bridges all the time.
But usually it's the vessel that's smaller or a similar size to the bridge.
This one was the other way around and a very long bridge to boot.
When I was a kid of about six, my uncle took me in his delivery truck for the day, drove me all around various neighbouring towns delivering dairy stuff. We stopped at a bridge, and he knew the chap who controlled the bridge, I got to go in the control room and pull the red lever to open the bridge. We opened it fully, and then waved through an American tourist who was piloting his beautiful glass-cabined river cruiser. And we all watched in amazement as he slowly steered it straight into the bridge and smashed it to bits, taking out pretty much the entire above deck area of the boat. So I think I can consider myself an authority here.
There is a trade off we make between convenience, cheapness and safety. Occasional interactions between critical infrastructure and mahoosive ships are the price of our demand for vast amounts of stuff to be brought almost into the heart of a city. I don't know if they could have done more to protect the piers, or used tugs more often for these vessels, but there is likely to be a financial consideration for both options.
Not a lot they could of done apart from drop an anchor.
The anchor is to stop a stationary boat from moving, not as a brake. Dropping it would either snap the chain or rip out part of the anchor handling mechanism.
Selling preventative engineering is hard work,
I can imagine.
In my field, obsolete kit is problematic. It's a security risk and if it goes bang tomorrow then we're screwed because manufacturer support is long gone. I used to harangue Sales to try and get customers to upgrade, they'd say the customer attitude was almost always "but why should we spend tens of thousands when what we already have just works?" And it's a fair argument, everything works... right up until the day it doesn't.
No it's not.
It is also used as an emergency brake.
That's why a ship's crew will clear away anchors, when arriving or departing a port, removing all the fastenings that are used to secure them at sea, then have a couple of crew members with a radio standing by to drop them quickly in an emergency.
Dropping a large ships anchor straight from the hawse pipe is not for the faint hearted and it puts loads of strain on the equipment but it is designed to be used like that if really necessary. It's not a routine operation.
There is an old saying "never go aground with your anchors in the pipes".
I'm guessing making those supports bigger and stringer would make the space between them even narrower. Which was probably all fine when the bridge was built but not now that ships have grown so massive.
@gobuchul the Chinese barge took out a section of the bridge with similar results. Was just pointing out it's not long since a very similar incident happened.
Dropping a large ships anchor straight from the hawse pipe is not for the faint hearted and it puts loads of strain on the equipment but it is designed to be used like that if really necessary. It’s not a routine operation.
Sounds like they got to test this on the Dali but it didn't stop them. Im guessing it could have even contributed to the incident pulling them further off course.
It could of easily put them further off course but that might of made things better, ie aground but not hitting the bridge or not hitting it as hard.
I can't see what action they could of took that would of made things worse?
I thought this was an interesting read.
https://twitter.com/cybergibbons/status/1772564868974915633
https://threadreaderapp.com/thread/1772564868974915633.html
Sounds like they got to test this on the Dali but it didn’t stop them. Im guessing it could have even contributed to the incident pulling them further off course.
How would it have done that? A ship swings round it's anchor, if it was caught it would have turned on it. Even if it was dragging it would swing. Probably, that's certainly the picture of the dynamics I have in my head.
I wasn't a deckie so have no idea what the procedure is but it could well have still been taking up slack in the chain when it hit. It if it was launched then the chain would have just flown out the locker until it hit the end. They're long buggers.