Suez Canal blocked by container ship 36

[verymadmac]

It might not be an engineering issue that started it, but I bet is going to change a few specifications.
BBC piece here Link



It looks like the bow is hard aground, refloating will be an interesting exercise given the time pressure.



Canal profile is here

https://www.suezcanal.gov.eg/English/About/SuezCanal/Pages/CanalCharacteristics.aspx

 

[TugboatEng]

That's a lot of stern. Naval architects are getting spoiled with z-drives and don't put the attachment points far enough forward on boats anymore. With the attachment points close to the steering there is no leverage and we can't pull and steer at the same time from the stern. As ship assist vessels we hardly ever work from the stern but we carry a rescue advertisement.

See the big deck on one of the most legendary towing vessels ever built, the Crowley Invader class. It's a Spaulding design and the Sea Robin and such were part but had less horsepower. The Invaders had 20 cylinder EMD engines. I operate a Spaulding boat built as the Phillip W and is currently called Patriot. That thing is a work of art compared to everything else I have come across. Spaulding was famous for using triple rudders and I know why but most of the industry doesn't. 3 rudders lets you move two outboard so they act as nozzles and give better bollard pull numbers while still maintaining nearly the maneuverability of a 2 rudder setup.

Then, Crowley partnered with a naval architect firm to design these lumps. I might operate one so I'm going to have to delete this post if it gains traction.

 

[1503-44]

Nice point about the tow point being too far aft and over the rudder. I can see where it could be useful to be able to steer while towing.

 

[Alistair_Heaton]

It was great to dive off even with the compressor on it and quads of nitrogen for making nitrox. Loads of room for kitting up and moving about. The toilet was brutal though by far the worst I have every used on a boat. And getting back onboard was very stress free. It was set up for commercial ops and there was room for a chamber but they didn't have it onboard for us.

I grew up in Aberdeen and went for regular walks on Torry Battery. Always loved watching the marine traffic in and out of Aberdeen harbour.

 

[Alistair_Heaton]

What's the different classifications of tugs?

I see you have used ship assist.

There seems to be a few other classifications out there.

Bollard
Harbour tug
Docking assist
Ocean

Smit and Alp seem to be the big boys in Europe and ME.

https://www.alpmaritime.com/fleet/alp-striker

Seen that one and its utterly colossal.

 

[JohnRBaker]

In 2018, when my wife and I did our four-island cruise in Hawaii for our 50th wedding anniversary (it was actually our 51st, but we had had to postpone a year due to my heart valve replacement surgery), one of the things that I spent time when entering and leaving the various ports was watching the different tug boats that we'd see. Now our ship itself didn't need any tugs, or at least I never saw any used to move our ship, the only thing close was just before we left Honolulu, a tug was used to move and then take away the fueling barge that was servicing our ship:

September 2018 (Sony a6000)

This one we saw that may have been escorting us into Hilo, on the Big Island:

September 2018 (Sony a6000)

Here's that same tug, the next morning at it's morring:

September 2018 (Sony a6000)

And I watched this one as we left Hilo:

September 2018 (Sony a6000)

And we saw this one in the harbor on Kauai:

September 2018 (Sony a6000)

And as we were waiting to disembark when we got back to Oahu, we saw this rather small tug towing a tourist submarine out of the harbor on one of their underwater excursions. I guess the sub, which actually did do a real submerge and was self-powered (we considered taking one on these rides but we got to the islands just as a hurricane had passed and they had suspended their scheduled trips and they didn't restart them until after our cruise ship had left and we only had one day in Honolulu after the cruise, so maybe next time) but I guess they only have enough power (they were electric) to handle the actual dive and underwater exploration, but didn't have enough power to go back and forth, from and to the port:

September 2018 (Sony a6000)

We watched several of these come and go as we waited for our assigned disembarking time.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[TugboatEng]

John, I love you sometimes. You posted pictures of Tiger tugs from Hawaii. We operated one for a minute. They're the worst boats ever built. Don't get me started on the plywood deck plates set 12 inches below every frame (3 feet spacing) so you can't walk through the engine room and a 5 ton rated winch on a 50 ton boat. Worst boats ever. The one called Freedom in your picture waa ours. I reconfigured the brake band on one drum so it could hold the pull. I also installed 3M Crystalline window tint on the wheelhouse to keep the captains from melting.

 

[JohnRBaker]

They look nice ;-)

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[Alistair_Heaton]

There definitely seems to be a difference of opinion across the pond on how to attach the tow hawser.

The big ones in europe with a winch have a BOP style hydraulic shear setup to cut the hawser remotely and the smaller ones that hook setup. That old clyde tug must be 1950's built and it has a quick release hook although that one was manual with a rope that to that passage way behind it.

Tugboateng please don't take this as a pissing match comment. Genuinely interested about the different philosophy's. I am happy that things are done differently either side of the pond, now more interested in why.

They're the worst boats ever built

Love it!!! sounds like me talking about BAe Jetstream 31's, only people that argue with me is Metro pilots and technicians.

 

[dik]

Do boats have a decking material. I suspect the steel deck would get quite hot in the sun... also some interesting thermal expansion effects... hot on top and cold on bottom.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[TugboatEng]

Allistair, the company that built that Tiger class of vessel bragged about the architect's ability to design a boat on a napkin and it showed. It showed at every level from building an 80ft boat that required class approval when 78 feet didn't, Winches from swampy Louisiana that didn't make 19% of the 3:1 safety factor, and German z-drives and their confused sourcing of parts. Our sister company pulled the bullnose off the deck and the class society gave it an as constructed rating of 15 tons on a boat that could pull 55 tons.

 

[dik]

A safety factor of only 1.5? Are Z-drives common... they appear to be mechanically inefficient...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

I did a elective course for a year on marine architecture didn't go near it again afterwards. Find boats very interesting though.

Once took a Captain of one of the channel island cat speed ferries on the jumpseat to get him out the the islands due some illness. When I was leaving CI at end of contract taking my car back to the mainland I ask one of the stewards on the pax decks if he was the boss that day. Turns out he wasn't but the skipper knew about the trip and I was on the bridge for the whole trip and loved it... Especially the banter with the duty engineer on the bridge.

 

[RedSnake]

What's the different classifications of tugs?

Here is some explanations between different tugs.

https://www.wartsila.com/encyclopedia/term/tugs

And here is the Swedish icebreaker tug Vilja (Volition) I guess in Finland she would have been named Sisu.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[waross]

An old tug-boat captain once told me of his impression of tug design.
Select the engine and prop that will do the job.
Add enough boat to keep them from sinking.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[TugboatEng]

Allistair, in the US, all boats have the hawser on a winch. Towing forces are transmitted to the vessel through the brake band. Some newer vessels have hydraulic or electric render recover modes and can tow without using a brake. There are few of these in the USA.

As for releasing the tow, with the exception of some low rent companies, the vessels have winches that can be free-spooled to ditch the tow in an emergency. The end of the hawser is fastened to the drum with a ssmallerline that will break when the hawser is dumped.

The horsepower of modern board is so great even the synthetic ropes are too heavy to handle by hand.

Dik, the nozzles z-drive is the most efficient methods of turning horsepower into bollard pull. Conventional boats drift with the current while pulling so you'll have to stop periodically and reposition the boat. There are boats with drives on the bow, most on the stern, some on either end. Each arrangement has advantages and disadvantages.

 

[Alistair_Heaton]

Interesting, I can understand why they do it with a hook this side of the pond I have seen a hawser start to part and they dumped it and it shot back and whalloped off the side of the vessel being pulled. No great lengths of cable in the water to foul things up and the tug has instant free movement.

Plus if marine ropes are anything like land based winch cables its an expensive and utter pain in the bum to keep them certified. And if you just have a hook which the hawser drops into you need less man power as well. The big boys have a small capstan winch to pull the hawser in via a messenger if they can't get under it.

 

[dik]

Thanks for the z-drive info... square cut crown and pinion? Braided polypropylene? size?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

If you mean when I saw it?

Diameter of my calf and it was some form of dead rope with a weave outside. It was a klondyker about to get sucked through the pentland firth. 20 min later one of the big boys from Shetland turned up and took it under tow with something twice as thick.

We weren't close so I don't know what they saw to trigger its release. We just saw it springing back towards the russian and the skipper of our boat, another dive boat from scapa. said that hawsers just parted.

 

[TugboatEng]

dik, z-drives all run palloid gears top and bottom. I've got a box open right now, I'll get you a pic of the upper gear shortly.

In USA ship assist tugs use some flavor of UHMWPE for the rope. Spectra and Dyneema are the dominant strands. In our fleet we run Samson Rope's Saturn 12 in 2-5/8 inch diameter.

 

[TugboatEng]

For Allistair, the weak link.