The Voith-Schneider Propeller

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[LucAtC]

Hello mvsmith,
Thanks  for the interesting infos!
While reading Voith Schneider Wiki pages, I found a pdf presentation of tugs and their operations http://www.comc.cc/pres/Allan%20Presentation.pdf
Being  unfamiliar with tugs and the tugging jargon (not  slang), I dont quite see the difference made between the popular à la Schottel propellers named (I think? Azimuth Stern Drive) AST and Z-drives. Also, to follow these texts is sometimes uneasy, concepts (or vocabular?) seemingly differing between Europe and US.
The best source I could find on it was http://www.solentwaters.co.uk/Site%20Map/
but  couldnt find unambiguous vocabular about tugs/operations.
Do you have also some links or tips about tug operations?
Regards,
Luc
 

[Kevinmcg_ships]

Hello mvsmith,

Yeah, that's her! She was a smashing wee ferry when she came up in the Clyde as the Sound of Sanda. When she was offered for sale in 1988/89, a community group in the Lymington area wanted to purchase her with the plan of preserving her (because she was world's first ferry of her kind). Sadly the Hampshire Council didn't agree and decided not to award them any money, so the whole project collapsed.

Instead she was sold to a fish farming company who cut her upperworks right down to the car deck. She is now all but broken up, in bits, and lying on a beach at Loch Evite (near Oban) in Scotland.

A very sad ending for a pioneering ferry. 

[mvsmith]

Luc, Thanks for the link.
Robert Allan is one of Canada’s leading Consulting Naval Architect firms, founded in 1930.
Three generations of Roberts have led the company.
The PDF of your link was an outline of a presentation to a conference in British Columbia.
You can see that there are many interesting developments in Tugboats, and the Pacific Northwest—B.C., Washington, and Oregon—is one of the centers of activity.
Developments are driven by a number of factors:
Ships are getting bigger, requiring not only more powerful ship-assist tugs, but greater maneuverability to berth those monsters.
The offshore oil industry requires tugs to tow the platforms, handle any ground tackle, and supply them. This has led to the development of Anchor Handling Tugs like the French Fairmount Sherpa and her sisters. These 200 tbp ships will soon be joined by a pair of 300 tbp AHTs ordered by Dreyfus. (tbp = Tons Bollard Pull)
Other big things such as oil refineries etc. are often fabricated in Asia and then towed half way around the world.
Another area that is serviced by Northwest firms is prevention and containment of oil spills.

The link has some nice pictures and gives some comparison of the various approaches to tug design.
I’ll look for more details and links.

As for vocabulary and idioms, ask me about specific things and I’ll try to answer without using yet more confusing idioms.
If they are embarrassing questions, such as “What are Port & Starboard”, you can PM me.

Marty
Try these links:
http://www.smit.com/ (http://www.smit.com/)  Nice screensaver & wallpaper

http://www.svitzer.com/Towage/Towage+Services/ (http://www.svitzer.com/Towage/Towage+Services/) Danish firm that bought Wijsmuller

http://agency.adsteam.com.au/about_adsteam_agency.asp (http://agency.adsteam.com.au/about_adsteam_agency.asp) Aussie, oowned by Svitzer

http://www.foss.com/ The home team

[mvsmith]

Luc,
This is Nanuq—Polar Bear in the Inuit language. She is one of the most powerful Voith Water Tractors in the world at 10,192 horsepower and 210,000 pounds bollard pull at almost 16 knots.
She and her sister Tan’erliq (Black Bear) were designed by Crowley Marine Services under contract with Alyeska Pipeline Service Company for tanker escort operations in Valdez Harbor and Prince William Sound, Alaska.

Nanuq is powered by two Caterpillar 3612 engines driving twin Voith Schneider Propellers.
She is fitted for tanker escort services, ship handling, firefighting, and emergency and spill response in Alaskan waters. Design features include a hydrofoil-shaped skeg, welded steel construction, transverse framing, wing tanks, and ice belting.
Nanuq was constructed at Dakota Creek Shipyard in Anacortes, Washington.


Two smaller VWTs for similar service, Abeille 31 and Abeille 32 are in service on the northern coast of France.
The VWTs Tystie and Duster do escort duty at the Sullom Voe terminal in the Shetlands.

This follows the Amoco Cadiz disaster off the Brittany coast in 1978, and the Aegean Sea at La Coruna, and the Braer in the bay of Quendale in the Shetlands.

[LucAtC]

Thanks, very interesting indeed, I also read the discussion how the escorting was modified to optimize the service, with the probable drift of tankers without escort.
http://www.seas.gwu.edu/~dorpjr/Publications/JournalPapers/TSMSIMerrick2002.pdf
I suppose Voith Water Tractor because of the main towing line being to the front instead being to the rear? Other tractor tugs being commonly Z-drive, or AST?
I couldnt find Abeille 31 and 32 position in France...
About RPA12 (not quite a tug), I dislike the fixed position because looking straight ahead, you have a wide spacer between 'windows', so that you cannot see where you are going.
Regards,
Luc

[mvsmith]

Luc,
Here are two links that may be of interest. The first is to Fairmount Marine. You can find information on Sherpa and the rest of the fleet.
http://www.fairmount.nl/page.php?idObject=369 (http://www.fairmount.nl/page.php?idObject=369)

This link is to Louis Dreyfus Armateurs, the French owners of Fairmount Marine.
http://www.lda.fr/  (http://www.lda.fr/)   

The Voith Water Tractor was named that by analogy to farm tractors, which are mostly stern drive, except for big articulated four-wheel drives.  It does not mean tractor in the bow drive sense.
In fact the builder of a VSP can  put the drives at either end or in the middle.
 
ASD means Azimuthing Stern Drive, a designation used by the Dutch builder Damen. Tugs of that type use something like a z-drive or azipod, usually 2, on the stern.
Damen’s site is www.damen.nl/  (http://www.damen.nl/)
 
Those two bees might not still be in service; I'l try to track them down.
Abeille 31 has been renamed Baobab. I haven’t located her, but there is a Baobab Marine Terminal, a Floating Production and Storage Offtake (FPSO) vessel moored 18 miles off the Ivory Coast, just west of Abidjan, West Africa. Perhaps she is working there.
Abeille 32 was renamed Flamboyant. I have no idea where she is.
Both bees are 4800 Hp; built in 1981.

Regards,
Marty

[mvsmith]

Luc,
Here is a link to an extract of a paper on how Pilots should work with ASD tugs: http://www.pilotmag.co.uk/articles/article.aspx?id=152 (http://www.pilotmag.co.uk/articles/article.aspx?id=152)
ASD tugs have some type of thrusters that can rotate 360 degrees mounted at the stern.
Azimuthing thrusters are of two basic types: Z-drive and AZIPOD.

Z-drives are mechanical drives where an inboard engine drives the propeller through a vertical shaft and two right-angle couplings—usually bevel gears. The propeller can be turned to face in any direction.
They were first developed Hollming in Finland in the 1960s.

AZIPODs are electric drives with the motor in a pod behind the screw. The whole pod is rotated through 360 degrees. The electric motor is usually driven by variable frequency AC through slip rings.
AZIPOD is a brand name  of ABB (Asea Brown Boveri, the merger of the Swedish and Swiss firms) (ABBA is the North American subsidiary of ABB—not to be confused with Agnetha, Björn, Benny, and Anna-Frid  …but I digress.)

[LucAtC]

Hello Marty,
A very good magazine, surely.
I knew reasonably well how Z-drives are functioning, for I knew the Schottel firm from 1969 on until 1986, having followed the developments of Rudder-Propeller and Pump-Jets, and visited Spay am Rhein some times.
Also of a US Z-drive with a MTBF of 68 hours, that Schottel intended to replace on board of MOFABs in the seventies (1978, I think).
As far as I know, the Z-drive SRP was invented in 1950 by Schottel and was installed on motorboats from then on.
Since then, thanks to all these drives, harbor tugs have taken new dimensions, gigantic thrust as well as new concepts for braking or steering while escorting.
I tried to simulate escorting, but my tugging skills are limited, the more one has to jump from tug to ship. It is nevertheless very pleasant.
Thank you, very informative sites indeed, my knowledge of tug operations is improving!
Regards,
Luc

[Stuart2007]

We learn something new every day...

I wonder why they don't use these vsp and other such things on large ferries? I presume that to make them work on such a large ship they would need each blade thingy to be too long for shallow water?

Stu

[LucAtC]

Indeed, a ferry like PoR would then undergo a major surge in redundancy of the propellers, with 10 VSPs installed.
Also, a gigantic improvement of gasoil consumption, thanks to the speed limited to some 15knots.
No longer endangering HM frigates thanks to dynamic positioning and no need of tugs, at the relatively small cost of the relative increase of complexity vs CPP/rudders. The manoeuvrability would be fantastic!
Of course, the 10 VSPs would need to be protected by grounding plates, with the benefit of an ability to moor in drying harbors. Moreover, the ferry could be a welcome attraction for the harbor, some kind of a monument to which Voith workers will be paying tribute.
As a secondary benefit, it could serve to control rolling of the ship.
But I couldnt find the unit price ? Would it be a problem?
Regards,
Luc

[Kevinmcg_ships]

Did you know there is a model version of Voith Schneider? (OMG!)

I once went to a model train exhibition that sometimes have model boats on display. I came across one half-completed model kit of Caledonian MacBrayne's MV Jupiter, a ferry which is driven by Voith Schneider units. He had drawn up an A4 showing his progress and that he was ordering miniature VSPs (he needs 2) for his model ferry. The exhibition is every November so I'm hoping go go there again next month and see if the model ferry has been completed.

Also I came across a website for a German model shop and they're selling a model kit of a VSP tug PARAT:

http://shop.graupner.de/webuerp/servlet/AI?ARTN=2095&language=en

There are a couple of nice pics, especially the underneath shots of the VSP's fitted to the model tug.

I would love to get my hands on this but unfortunately my model making skills is only restricted to building Airfix, Tamiya, Thumpeter kits!

[mvsmith]

Stu,
Here’s a Kort nozzle on a Thrustmaster Z-drive, for the Peruvian tug Cabo Blanco in Callao.
Built for Agencia Maritima Cosmos, she has a pair of Cummins KTA-50-M2 main engines—each delivering 1600 bhp @ 1800 rpm.

[Tavares Junior]

Hello Marty,
Just seeing the important debate about the VS tug's I would like to make my comments too.

The VS Tugs are well designed to operate at the vessel's Stern (Sccort as previous mentioned by you) The only problem found with the VS Tugs are the draft limitation due to the location of it propulsion units (Under the Hull) those units are protected by a hydrofoil under under the blades wich are designed to stabelize the tug and protect the blades in case of grounding.

Here in Brazil i had participated on the sea test of the MORPHEUS and MORAS  The newest VS Tugs that we have here also the Harbour and Towning test was really nice, during the bollard pull test of the MORAS the Capt had agrounded the tug was the test was taken into the port of Itajai (South of Brasil) this port is located into the Itajai River within 200m width.

The test was stoped and the Tug was pulled back to the yard after landing and several exames and survey no damages was found to the grounding plates and or propulsion units and its blades.

these 2 tugs are 80tons bollard pull and goes closer to 14Knots. I will send you some pictures soon

About the robert allan project the SMIT TAK has just bought the REBRAS and ordered the 18 builds of the ASD's 8x80tons bollard pull and 10x50tons bollard pull

But on my opnion the must maneuvarable tug still the ROTOR TUG's wich can assit the vessel's during scort and even on the FWD for berthing and umberthing. I think do you know those tugs better than me. But I gonna meet then now in 2008 in Rotterdam during my pilotage course.
Here in Brazil we frequently working with ASD's tugs as these type does not suffer many restriction due to her draft. Is commom for us here to work with ASD's at the ship's stern and Double screw at the FWD for berthing and umberthing maneuverings.

Cheers

[mvsmith]

Hello Marty,

Here in Brazil i had participated on the sea test of the MORPHEUS and MORAS  The newest VS Tugs that we have here

Tavares,
Thanks for adding information to this topic.
DJM will be pleased to hear that a tug has been named for him!
Best regards
Marty

[Shipaddict]

Haha, yes. DJM wil be pleased!

[[RWP]DJM]

ROFL you guys

I'd like to make a skin for my own P6 to be honest......DJMegaCop on the side of it

Regards.

DJM.