THE CHAIN LOCKER
The video above should pique the interest of any tugboatman - it's about a unique development of the familiar "tractor" tug design we all know something about. These new Rotortugs (actually, the idea is about a decade old) incorporate a third thrusting unit. Very cool!

Tractor tugs of all types arguably represent a bigger leap forward in utility than when the industry moved from single-screw to twin-screw tugs, or - before that - from steam to Diesel propulsion. They're that big a deal. The revolution has come over decades, but even in the sometimes slow-to-change maritime business this revolution is a fait accompli.

The "reverse tractor" or Azimuthing Stern Drive (ASD) Z-drive tug has become a North American staple; they're commonly seen now in most ports, even on the East Coast. They're massively useful in comparison to a traditional single- or twin-screw boat. 

On the US West Coast, and in Alaska, Europe, Asia and other parts of the world, conventional tractors - the ones with the thrusters arranged at the bow of the tug - are common, with both Voith-Schneider and shrouded propeller Z-drive thrusters in use. The original "tractors" were of this design, using Voith-Schneiders. I had a friend who ran conventional tractors down in the Panama Canal Zone, and he liked them very much. 

Voith-Schneiders (in his view, at any rate - I've never run one) are simpler to learn, coming very naturally to many operators. Thruster-equipped tugs are said to require more training. On the other hand, thruster-equipped boats generate more bollard pull than the Voith-Schneider boats from the same horsepower. 

I'm used to the ASD type, having trained on them and run them during ship jobs from time to time. 

But the Rotortug is an entirely different animal! I've been reading about these for several years, and the concept looks really interesting. But there's so much I don't know about them. 


For instance, as an ASD driver I can see how the third thruster would enable you to do some additional things. But I wonder, how is the third unit operated? Both my hands are occupied when I'm running an ASD, so I'm not sure whether a Rotortug pilot presses his feet into service, or just operates the third thruster in a conventional way, taking one hand or another away from the twin controls when he needs to. I'd love to know! 

On some of our tugs, foot pedals operate the forward line winch - so I could see thruster foot controls as a solution. Anybody know the answer to that?
Picture
Robert Allan/Rotortug - click on picture for article
At right is a graphic showing the Rotortug thruster arrangement. Clicking on the picture will take you to Maritime Executive's site and an article about Robert Allan Ltd. and Rotortug (KST) B.V. signing an agreement for the development of future Rotortugs. This should be a promising marriage - Rotortug created the triple-thruster concept, and Robert Allan is internationally known for his excellent tug designs. 

Some of the ASD tugs I've trained on & operated were Robert Allan designs, using Ulstein units similar to those in the video, and they were very good tugs indeed - light and highly maneuverable, with excellent visibility. 

And I've also run Schottel units in ASD configuration in a heavier, deeper, slightly less maneuverable Jenson design that, although a little slower, rode better in a sea and might have featured a little more bollard pull at the same horsepower. Both tugs were excellent shipdocking tools.

The three-thruster Rotortug design looks challenging to run (since I know nothing about how it's done). But I'm sure that the additional capability is controlled in such a way that it's not a problem. And once you've mastered it, I'll bet you can do some amazing things with it! I'd love to try one.


Do you have any experience with Rotortugs - especially with the control arrangement? Let us know about it by posting in the Comments section below!

6/18/2012 11:48:47 pm

Dear All,

Please look at the new website of Rotortug.com and visit the 360 tour at the bottom. You can navigate by pushing on the small model in the left down corner. In the 360 picture at the bridge you see the three handles. by pointing and clicking with the mouse on the handles you find a small movie about operting a rotortug. You will find hidden information and movies all over, have fun!

Any further questions don't hesitate to email me via the website

Kind regards

Evan Willemsen
Managing director

Rotortug

Reply
William Redington
11/17/2016 08:20:26 pm

Dear Evan

Please explain to me why the pair of drives are on the bow while the single drive is on the stern. Why would you not have the drives mimic an ASD with the single drive on the bow. I dock ships in Tampa Bay and i am familiar with both SDM's and ASD's. With your setup you lose the stopping power of transversing while center chaulk aft. Not to mention that the working line will hold your bow in position while on the quarter or the bow. Essentially your company has just made an SDM with an extra drive up forward rather than an ASD with a drive on your bow acting as a thruster. Im sure through your hydrodynamics you guys have found that this is more efficient but will you please explain.

Thank you for your time.

Regards
William Redington
Redingtonwilliam@gmail.com
7272691862

Reply
6/19/2012 09:14:52 pm

Dear Evan,

Thanks for pointing that out! I can't watch all the videos for some reason (perhaps a bandwidth limitation?) but the virtual tour is very cool! Especially the explanation of the hybrid features.

I've never had any experience with a hybrid plant, but I'd love to run a tug like this one! You guys have done a wonderful job on the design and execution.

Thanks,

Reid

Reply
6/20/2012 08:06:30 pm

Dear Reid,

You are most welcome and have a try on one of the Rotortugs operated her in Rotterdam.

I think the band with migth be the problem, however, I will have a look if I can post all of them on youtube. Keep you informed.

Kind regards

Evan

Reply
6/20/2012 08:56:53 pm

Dear Evan,

Tried the video with a Macintosh laptop (my work computers are Ubuntu Linux) - and it worked fine. So it might be a codec issue on my work machine, and nothing to do with your site! Although I usually am able to play and embed YouTube videos without trouble on the Linux machines. Your site is very well done and interesting - it really helps the visitor to understand some of the Rotortug's unique differences.

Thank you for the invitation! I haven't been to Europe since I sailed deep-sea, many years ago. But if I were able to come, Rotterdam would be one of the places I would want to visit, and what could one find better to do there than to try one of your amazing tugs! I don't anticipate being able to take you up on it, but one never knows what life brings - hope I can visit one day.

Our own tugs are reverse tractors, 65T, FiFi-1, with Ulstein and Schottel units, and line winches but no render/recover - all built between 2003 and 2006, to Robert Allan & Jenson designs. They're very nice boats, but it's interesting to see how technology speeds along. There was a time when I would have called them "state of the art" but no more.

Here is a link to our website: http://www.cestugs.com/Home.aspx If you're ever in our neighborhood, please stop in.

Sometimes I think if someone would create a video game in which the player could run the various types of tractor tugs, it would be a hit! They certainly are fun to run, and amazingly capable.

I hope we can meet one day, and I can see your fleet!

Thanks,

Reid

Reply
6/20/2012 09:34:45 pm

Dear Reid,

At this very moment we are studying a small internet based simulation programm, together with Force Denmark to let people steer their own rotortug. Very simple and basic but still, it will be fun I think. As soon as it will become reality I will inform you.

The choice of concept, tractor, ASD or Rotortug is very much depending on the operational needs , geographic circumstances and operational profile. Neither is good or bad, but they are all different. Ofcourse the Rotortug offers you the best possibilities of all! It is up to the operators, which system they choose. For us it would be very interesting to learn how the North American market is adapting to this concept or even embrace it.

We have a very good exclusive co-operation with Robert Allan, which means that RAL is the only naval architect who is allowed to design new Rotors, called the Advanced Rotortug (ART) next to the existing designs so called RT's. A 3D model for the Port Hedland tugs in Australia is shown on our website and is presently tendered for.

When ever I am in your neighbourhood, I will contact you.

Kind regards

Evan

Peter
10/8/2012 10:41:20 am

I dont understand in this current climate why anyone would want to run a vessel with 3 engines and 3 propulsion units???
The running costs and the maintenance would be astronomical.
Futhermore the extra concentration that would be required to operate the extra propeller and engine. I would not want to be in one of these tugs in an emergency situation. Its hard enough to control a standard vessel.

Reply
10/8/2012 05:04:13 pm

Dear Peter,

You will have to look to a tug boat in terms of bollard pull. If you need let's say 80 tons bollard pull you will need a certain amount om Kilo Watts to generate this power. It doesnot matter if you generate this with two engines or with three engines. I would like to go further. You have three smaller engines and three smaller propulsion units installed instead of two bigger ones. You can mobilize on one engine and thruster instead of always have the two engines clutched inn. If one of your thrusters or engines is not working , with a Rotortug tug you can still continue to work, with less bollard pull, with a standard tractor you are out of service. Station keeping in current is a lot more efficient with a Rotortug becaus you don't have to "force" your tug all the time, anyway, many advantages and no disadvantages.

I am present at the boat show in New Orleans if you are there we can continue our conversation.

Yes the Rotortug has three engines and three thrusters but they are smaller and you are more efficient in using them, thus using less fuel.

Looking forward to see you in NO

Kind regards

Evan

Reply
Reid Sprague
10/8/2012 08:50:42 pm

Dear Peter,

I'm chiming in after Evan, but as a tractor operator myself, I'd concur on the control issue. Not only am I tractor-trained, but before that I worked for a company that had converted several single-screw tugs to "Combi-tugs" - single-screw tugs that had had an azimuthing thruster installed in the bow.

These BT weren't equal in thrust to the main; in a 2400HP single-screw tug, for instance, we had installed a thruster of approximately 700HP. But it was enough, with leverage and the added efficiency of the shrouded prop, to effectively oppose the main, especially at angles (where the main still used the existing rudder). The operating principal was different from a tractor, but it greatly added to the flexibility of the tug.

And it required us to handle three inputs: the integrated control for the thruster, similar to the ones in the Rotortug; the throttle for the main; and the rudder. After a little break-in, we handled it fine - and really missed the thruster if it ever went down! It wasn't an extra burden, but an extra capability.

Evan, I agree with your argument vs. continued ability to operate even when losing one unit - if a stern unit, the tug could still be operated similar to the Combi-tug, if the bow, then it could continue as a conventional tractor. Although I have seen our tractors finish a job after losing a thruster (in that case, operating as a single-screw!) But you're right, you'd never dispatch a tug to a job under those circumstances! Where I could see a Rotortug continuing to fill a spot in the rotation even with one unit down.

Reply
10/8/2012 05:15:52 pm

Peter,

Now about the controls:

If you need to control a vessel with only two thrusters you are constantly correcting the tug. Look at the Rotortug as a ship with a powerfull maneuvreble bowthruster and a powerfull maneuvreble sternthruster. You will find youself in the situation that you are always in control of you vessel and that in difficult circumstances you are still able to transfer towline forces always in a safe situation. The three handles are used in couples, you get used to it easily. Yesterday I had tugboat captain on the bridge for the first time ever sailing a Rotortug. He performed two assistances under supervision. One at the bow and one at the stern. He loved it!

The difference with any other tug is that you are always in control with a Rotortug and even if you make a mistake, this can be corrected at all times, which is not possible with a stern drive.

Please have a look at the website and check the short movie at the subpage of Rotortug called power You see that sailing a Rotortug is easy!

If I was in an emergency situation, I would prefer a Rotortug over any other type of tug, but you will have to experience yourself because I am prejudiced ....

Kind regards

Evan

Reply
Reid Sprague
10/9/2012 01:27:53 pm

Just re-read my comment and realized it wasn't clear. I agree with Evan that the third control input should not be a problem - having had experience in a somewhat analogous situation with the Combi-tug, which had you juggling rudder, main throttle, and thruster control all at once. We not only learned it fairly quickly, but really missed that third input - the thruster - when it wasn't available. Controlling a Rotortug (although I haven't had the experience) should not be a problem, and might soon become addictive!

Reid

Reply
peter
10/10/2012 08:57:48 am

Thanks Reid and Evan,
I have had a look at the tugs on the website, and also on Rbert Alan's site. I did see the rave tug on Roberts site,that tug looks like an interesting beast as well, pretty much the same looking vessel from the water inline up.
I will be in a port in Western Australia next week, where they are operating Rotortugs on lease, Im looking forward in hearing and seeing these vessel in the field. thank you both for your replies.

Reply
10/10/2012 05:13:26 pm

Peter,

Good to hear from you and I trust you will get positive replies from the Rotortug operators in WA. Have a safe trip!

Kind regards

Evan

Reply
MARK S LEWIS
3/22/2013 07:51:00 pm

I AM JUST ABOUT TO START TRAINING ON A ROTOR TUG I HAVE FOUND ALL INFORMATION GIVEN BY ALL VERY HELPFUL GIVING ME ALOT OF GOOD TIPS FOR THE FUTURE ONCE MY TRAINING HAS BEEN COMPLETED I WILL BE IN A POSITION TO ADD MY EXPERIENCE IN THIS MATTER

Reply
3/27/2013 08:23:57 pm



Rotortug and Robert Allen sign agreement with Damen Shipyards


Rotor®tug is proud to announce that Elisabeth Ltd has placed a new building order with Damen Shipyards for the construction of two Hybrid Advanced Rotor®tugs ART 80-32 of 80 tons bollard pull. Simultaneously Elisabeth Ltd ordered two ART 80-32, with Fifi 1, at Cheoy Lee Shipyards Ltd.

They will be the first series of Rotor®tugs to be built at Damen Shipyards and Cheoy Lee Shipyards Ltd and will be added to the Kotug fleet.

This ART 80-32 is the third Rotor®tug design originating from the co-operation between Rotor®tug and Robert Allan Ltd and the follow up on the first Hybrid Rotor®tug ever, the RT Adriaan, refitted by Aspin Kemp Associates Ltd under supervision of the new building department of Kotug.

Today an agreement was signed between Damen, Robert Allan Ltd and Rotor®tug which enables Damen to build ART 80-32 Rotor®tugs for third parties. A separate signing ceremony with Cheoy Lee will be organized soon. This agreement between parties announces the beginning of an new era for the Rotor®tug propulsion configuration. It is now possible to buy a Rotor®tug, designed by Robert Allan Ltd, built by Damen or Cheoy Lee.


Damen and Cheoy Lee are planning to integrate the ART 80-32 into their harbor/terminal tugs portfolio. This will give them the opportunity to offer on tenders requesting Rotor®tugs for their performance, redundancy, superior safety and unique maneuverability.

http://www.rotortug.com/en-GB/news/47_rotortug-and-robert-allen-sign-agreement-with-damen-shipyards.html

Reply
Evan
6/11/2013 12:40:55 am

Reply
Peter
7/18/2013 10:00:32 am

With the Rotortugs so called active skeg. What happens to the tugs handling if you lose power to that propellor if your in escort mode?

Reply
7/18/2013 11:09:04 am

Dear Peter,

I can't speak from experience with a Rotortug, as Evan would be able to do; but the reverse tractors we are using right now in my company do not have a skeg at all - just a fair hull forward. This is because in our use case, maneuverability is more important than steering leverage on the line, and the tugs are very quick without the skeg.

I would think that a Rotortug with the "active skeg" thruster down would handle much the same as our boats - with the third thruster down the operator would have to go back to traditional tractor techniques and would have less power to apply, but he should remain in full control.

Evan?

Reply
Luke
8/28/2013 04:17:50 pm

All I had a week training and driving Rotortugs (I will keep the location to myself) a couple of weeks ago. I have been a tug master for some 25 years and have driven every type of tug known all over the world. Never have I experianced such a horrible vessel in all my life. The tug did not responed or have the capabilities in escorting as I have read, in 25 years i have never been so worried and concerned doing an indirect.. Three propellers are a joke. and dangerous in my option. WHY ?? No thank you mr Rotortug i will not be recomending these things to my board.

Reply
Andy
11/19/2013 04:57:49 pm

Luke, i'm not sure if i agree with your comments, but i appreciate everyone is entitled to their opinion. I have been Captain of a Rotor tug for 4 months now having undergone a training scheme. My experience is (5 years+) of ASD and now i've been spoilt with Rotortugs I wouldn't go back.!

To answer the initial question, principally the tug is handled with a forward (Stbd) and Aft thruster, therefore with a control lever in each hand. The third (port forward) is then introduced to add the additional force.

The most interesting ability with this type of tug is that the tug does not need to be orientated (as you would for an ASD for example) before the weight is applied on the line, thus reducing reaction/response times to pilots requests.

Reply
2/17/2015 09:21:45 am

I have experienced as ASD Tug Master since 1997, any idea which company can accommodate me to get into the Rotor Tug?

Reply
Reid Sprague
2/17/2015 10:53:58 am

Ode,

Where do you live and work? I know of no one on the U.S. East Coast currently using Rotortugs, but I think I have seen some mention of them on the U.S. West Coast. As noted above, they are in use in Western Australia and in Europe.

Perhaps Evan could direct you to companies in your part of the world, if you can let us know where you are.

Good luck, Ode! I'd love the opportunity to run one someday.

Reply
2/17/2015 11:36:40 am

I live in Indonesia and currently seeking a new opportunity, I use to work for Sembawang Maritime Ltd/PSA Singapore (Singapore and Malaysia water), Svitzer (Iran, Qatar LNG and East Timor/Darwin), P&O (Spain and Egypt Shokna Port) and the last one for Smit Lamnalco (Yemen LNG Terminal and Papua New Guinea LNG Terminal) on board various Tractors and Pushers Tug.


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