Kawazaki wrote: Fri Mar 26, 2021 11:40 am
Can anyone in the know explain how tugs work? Do they just have more/bigger blades on their propeller(s) attached to a bigger engine(s) or is there more science and engineering in play?
Slow bumper boats with tons of torque?
Re: Suez canal blocked
Posted: Fri Mar 26, 2021 12:18 pm
by TB63
Physics..
Same way a 60 ton canal boat can be moved by 1 person..
Re: Suez canal blocked
Posted: Fri Mar 26, 2021 12:59 pm
by Hal Jordan
What are they like on a treadmill?
Re: Suez canal blocked
Posted: Fri Mar 26, 2021 1:36 pm
by Uncle fester
vball wrote: Fri Mar 26, 2021 11:39 am
What would the difference be in journey time from say Gibraltar to Mumbai going around the Cape compared to going via Suez?
I just wondered when the ships started using that route.
Adds a week to transit time I think.
Re: Suez canal blocked
Posted: Fri Mar 26, 2021 1:58 pm
by Rhubarb & Custard
TB63 wrote: Fri Mar 26, 2021 9:05 am
They're going to try on Monday as it's a spring tide, all, of 2 metres of it... Be 8.4 metres for us locally...
I hadn't thought of that, the tides that is, pretty daft but I didn't think beyond canals just stay level. I wonder when they'll get into low tide problems and the boat sitting down still more and/or damaging the hull structure
Re: Suez canal blocked
Posted: Fri Mar 26, 2021 3:57 pm
by Chrysoprase
Hal Jordan wrote: Fri Mar 26, 2021 12:59 pm
What are they like on a treadmill?
1) Why no ground base winching? Bring in, anchor them and pull?
2) Skycrane the load off to lighten the ship? Or are freight containers too heavy for that?
Ships are not designed for those kind of stresses. Good chance it'll rupture of you try to haul it like that.
The thing is the same length as the empire state building. Would take too long to get the load off but they might have to do it if the wee digger can't do the job.
The issue is the required foundations for any land based winch system, just not possible in short term and sourcing those winches would be tricky.
The vessel will have adequate strength for towing off, I don’t see any structural concerns even if the bow is no longer water tight.
Basically, more tugs are needed once the bow section is cleared but it is likely aground too so they will be looking at how to lighten the load.
Salvage companies will be making a killing.
Towing along the axis of bow to stern sure but wouldn't be so sure about a load coming in at oblique angle.
Ships are not designed for those kind of stresses. Good chance it'll rupture of you try to haul it like that.
The thing is the same length as the empire state building. Would take too long to get the load off but they might have to do it if the wee digger can't do the job.
The issue is the required foundations for any land based winch system, just not possible in short term and sourcing those winches would be tricky.
The vessel will have adequate strength for towing off, I don’t see any structural concerns even if the bow is no longer water tight.
Basically, more tugs are needed once the bow section is cleared but it is likely aground too so they will be looking at how to lighten the load.
Salvage companies will be making a killing.
Towing along the axis of bow to stern sure but wouldn't be so sure about a load coming in at oblique angle.
They are designed for loading in many planes, the forces exerted when moored are similar to what will be seen during salvage operations.
Re: Suez canal blocked
Posted: Sat Mar 27, 2021 11:02 am
by Uncle fester
That doesn't seem plausible.
Re: Suez canal blocked
Posted: Sat Mar 27, 2021 11:41 am
by shaggy
Uncle fester wrote: Sat Mar 27, 2021 11:02 am
That doesn't seem plausible.
In what way? When a ship is moored at a berth the mooring lines are deployed to prevent longitudinal and transverse movement so the loads imparted to the ships mooring equipment will not be acting in just one direction.
The classification society design codes cover this.
Re: Suez canal blocked
Posted: Sat Mar 27, 2021 7:08 pm
by Sandstorm
Just seen my date of my Amazon delivery shift out 8 weeks overnight for a cat hairbrush I ordered from China. I suspect it’s on this bloody container ship.
Re: Suez canal blocked
Posted: Sat Mar 27, 2021 7:14 pm
by Uncle fester
Sandstorm wrote: Sat Mar 27, 2021 7:08 pm
Just seen my date of my Amazon delivery shift out 8 weeks overnight for a cat hairbrush I ordered from China. I suspect it’s on this bloody container ship.
Sandstorm wrote: Sat Mar 27, 2021 7:08 pm
Just seen my date of my Amazon delivery shift out 8 weeks overnight for a cat hairbrush I ordered from China. I suspect it’s on this bloody container ship.
#prayforsandstorm
I'm shocked he's told us he has cat hair; now I imagine him looking like this ....
Sandstorm wrote: Sat Mar 27, 2021 7:08 pm
Just seen my date of my Amazon delivery shift out 8 weeks overnight for a cat hairbrush I ordered from China. I suspect it’s on this bloody container ship.
#prayforsandstorm
I'm shocked he's told us he has cat hair; now I imagine him looking like this ....
You don’t understand, it’s made of cat
Re: Suez canal blocked
Posted: Sun Mar 28, 2021 7:03 am
by Torquemada 1420
Kawazaki wrote: Fri Mar 26, 2021 11:40 am
Can anyone in the know explain how tugs work? Do they just have more/bigger blades on their propeller(s) attached to a bigger engine(s) or is there more science and engineering in play?
Don't know about tugs specifically but would think it would depend upon application. All of them will have powerful, high torque motors. In shallow waters, too much speed will result in the boat dragging.
I can't imagine the blades differ much between them nor in ratio to any other size of boat: there are practical issues with over size props including stuff like balance, leverage etc
I suspect the difference between tugs will be their shape and draught which will be different for ocean going and inland/harbour use. Also dimensions (width: a wide tug can deploy more props). They must me more agile too (maybe they have thrusters or can vary prop pitch and angle?).
Kawazaki wrote: Fri Mar 26, 2021 11:40 am
Can anyone in the know explain how tugs work? Do they just have more/bigger blades on their propeller(s) attached to a bigger engine(s) or is there more science and engineering in play?
Don't know about tugs specifically but would think it would depend upon application. All of them will have powerful, high torque motors. In shallow waters, too much speed will result in the boat dragging.
I can't imagine the blades differ much between them nor in ratio to any other size of boat: there are practical issues with over size props including stuff like balance, leverage etc
I suspect the difference between tugs will be their shape and draught which will be different for ocean going and inland/harbour use. Also dimensions (width: a wide tug can deploy more props). They must me more agile too (maybe they have thrusters or can vary prop pitch and angle?).
Huge variation in tugs based on their role. Harbour tugs need manoeuvrability, deep sea tugs need horsepower. Propulsion systems can be hugely different with traditional controllable pitch propellers, azimuthing units which vary direction, speed and pitch and then you have Voith Schneider. They all have a lot of installed power for pulling and/or pushing.
Re: Suez canal blocked
Posted: Sun Mar 28, 2021 9:09 am
by Sandstorm
Holy shit! Have we finally discovered a topic that all Bordies know nothing about?????
Re: Suez canal blocked
Posted: Sun Mar 28, 2021 9:57 am
by shaggy
Sandstorm wrote: Sun Mar 28, 2021 9:09 am
Holy shit! Have we finally discovered a topic that all Bordies know nothing about?????
Almost all.
Re: Suez canal blocked
Posted: Sun Mar 28, 2021 10:47 am
by TB63
Just look up bollard.pull.
Be very careful with your spelling...
Re: Suez canal blocked
Posted: Sun Mar 28, 2021 10:51 am
by Glaston
Sandstorm wrote: Sun Mar 28, 2021 9:09 am
Holy shit! Have we finally discovered a topic that all Bordies know nothing about?????
Uncle fester wrote: Sat Mar 27, 2021 11:02 am
That doesn't seem plausible.
In what way? When a ship is moored at a berth the mooring lines are deployed to prevent longitudinal and transverse movement so the loads imparted to the ships mooring equipment will not be acting in just one direction.
The classification society design codes cover this.
There's a big different between the forces applied when a boat is moored versus when folks are trying to haul it off being grounded.
Uncle fester wrote: Sat Mar 27, 2021 11:02 am
That doesn't seem plausible.
In what way? When a ship is moored at a berth the mooring lines are deployed to prevent longitudinal and transverse movement so the loads imparted to the ships mooring equipment will not be acting in just one direction.
The classification society design codes cover this.
There's a big different between the forces applied when a boat is moored versus when folks are trying to haul it off being grounded.
Really? That should be easy to show then?
Re: Suez canal blocked
Posted: Sun Mar 28, 2021 6:23 pm
by Fangle
I heard on a local radio that this could cause a toilet paper shortage a people panic. Fear-mongers.
Shaggy, isn’t your job something to do with shipping? Captain or something? Or is that someone else. I know you’re not the Argentinian ref.
Re: Suez canal blocked
Posted: Sun Mar 28, 2021 8:01 pm
by shaggy
Fangle wrote: Sun Mar 28, 2021 6:23 pm
I heard on a local radio that this could cause a toilet paper shortage a people panic. Fear-mongers.
Shaggy, isn’t your job something to do with shipping? Captain or something? Or is that someone else. I know you’re not the Argentinian ref.
Yes, something to do with shipping. Enough to know what I am talking about anyway.
Re: Suez canal blocked
Posted: Sun Mar 28, 2021 9:23 pm
by fishfoodie
Is anyone on the hook; liability wise for this little blockage ?
Was the Pilot onboard, or was this before they pick them up ?
In what way? When a ship is moored at a berth the mooring lines are deployed to prevent longitudinal and transverse movement so the loads imparted to the ships mooring equipment will not be acting in just one direction.
The classification society design codes cover this.
There's a big different between the forces applied when a boat is moored versus when folks are trying to haul it off being grounded.
Really? That should be easy to show then?
No need to be a prat about it.
Mooring is a bit static compared to dynamic forces from great big tugs.
Re: Suez canal blocked -- NOT ANY MORE
Posted: Mon Mar 29, 2021 4:12 am
by Kiwias
Just being reported that the Ever Given has been refloated.
No need to be a prat about it.
Mooring is a bit static compared to dynamic forces from great big tugs.
I was giving you enough hints but you kept/keep on digging.
No, mooring is not static in any way, in fact the loads can be far more dynamic and variable than from towing or escort duties.
Fair enough so.
Re: Suez canal blocked
Posted: Mon Mar 29, 2021 7:11 am
by TB63
Saw a graphic on the track and position of the ship prior to it grounding. High wind was behind it as she entered the canal but on the first bend, she slewed, so they corrected for her to slew again, and again etc.
Basically the world's slowest tank slapper...
Re: Suez canal blocked
Posted: Mon Mar 29, 2021 7:46 am
by Torquemada 1420
shaggy wrote: Sun Mar 28, 2021 8:40 am
Huge variation in tugs based on their role. Harbour tugs need manoeuvrability, deep sea tugs need horsepower. Propulsion systems can be hugely different with traditional controllable pitch propellers, azimuthing units which vary direction, speed and pitch and then you have Voith Schneider. They all have a lot of installed power for pulling and/or pushing.
Interesting in how much overlap there is with aircraft prop technology which, I guess, should be no surprise. Air only a slightly different fluid to water!
Voith Schneider is a newbie. Would not work on a plane.
This is really cool:
I assume this means they must be mounted under the hull sat facing down i.e. a bastardised paddle steamer?
Sandstorm wrote: Sun Mar 28, 2021 9:09 am
Holy shit! Have we finally discovered a topic that all Bordies know nothing about?????
Globus is unwell.
He's clearly not seen this thread yet. Given he invented the tug, and project managed the construction of the Suez canal he is well placed to answer.
Re: Suez canal blocked
Posted: Mon Mar 29, 2021 7:48 am
by Torquemada 1420
Fangle wrote: Sun Mar 28, 2021 6:23 pm
Shaggy, isn’t your job something to do with shipping? Captain or something? Or is that someone else. I know you’re not the Argentinian ref.
shaggy wrote: Sun Mar 28, 2021 8:40 am
Huge variation in tugs based on their role. Harbour tugs need manoeuvrability, deep sea tugs need horsepower. Propulsion systems can be hugely different with traditional controllable pitch propellers, azimuthing units which vary direction, speed and pitch and then you have Voith Schneider. They all have a lot of installed power for pulling and/or pushing.
Interesting in how much overlap there is with aircraft prop technology which, I guess, should be no surprise. Air only a slightly different fluid to water!
Voith Schneider is a newbie. Would not work on a plane.
This is really cool:
I assume this means they must be mounted under the hull at facing down i.e. a bastardised paddle steamer?
