Thanks to all for the explanation on Schottel and azimuth drives.
len

"A picture is worth a thousand words."

(I have two Graupner schottles, also known as z-drives for a towboat, but never started.)

Lew
Florida ⛱️, USA

Hi Schottel is as described a shrouded propeller that can rotate its direction like a rudder. The drive for it is in the hull.

Azimuth drive is an underwater pod that also turns like a rudder but the motor is contained in the pod.
On the many large cruise ships that are around they may also have a fixed pod drive at the bow and 2 azimuth drives at the stern. The pods are used prop first in direction.
No rudders are used in both of these type of drives.

One of the benefits for the cruise ships is that the big diesels can be arranged around the hull to distribute the weight and also a diesel can be serviced at sea as it is probably one of four or more supplying the power needs.

The diesels all drive alternators that produce eventually a DC current. This goes to a central control and for the engines it is turned into a variable frequency AC which drives the engines which are very similar to brushless motors. It will also supply standard mains AC at 50 htz.

When a cruise ship is in a hot/warm climate the air conditioning may well be as much or perhaps more than the power needed for the engines.
If you check the performance of a cruise ship you will see that in the main cruising speed is about 18 knots, top speed is about 22 knots. Length of ship comes into play as well.

Do not confuse purpose built cruise ships with North Atlantic Liners. I think QM 2 is the last of these and they can maintain 30+ knots and are strengthened at the bow to stand the rough weather in the Atlantic.

A further point is that the quoted tonnage is not the displacement of the ships it is just the Gross Tonnage measured as 1 tonne per cubic meter of usable (what can be sold) space so e.g. the engine room is not included.
So whatever the latest largest cruise ship is and quoted as say 140,000 tons the displacement is a lot less!
Where-as for Naval aircraft carriers it is a displacement measurement.

Well there you are, feel free to pick me up on any errors!

Hope this answers your question. If you want absolute information then Richard Simpson who writes for Model Boats magazine is your man. I wrote an article on the workings of the Queen Victoria at launch and Richard checked it over for me before publishing.
Roy

A Schottel drive is like a large barrel that has no bottom or lid. The drive screw is located in this barrel. The entire barrel is turned to steer. It's a bit simple to explain but I hope you understand it. I don't know the other drive either.

Pardon my ignorance, but what is a Schottel or an azimuth drive?

Having looked at the Fairplay group of tugs, I rather favour one of them. Schottel or an azimuth drive as there is no provision for stern tube or rudder.

The very regular port holes suggest a kit when compared with the assembly, they have been neatly cut.

I suspect it has been the project of an older person feeling a bit bored and perhaps running out of time.....

On balance I would finish her, all of the dodgy work will be covered up anyway and in bright colours and some extra detail in the bridge area she could be transformed.

You say you have Schottel drives with the boat does that include motors? If powerful that might suggest what was needed for the model.

Good luck with the project.
Roy

Newby
It’s your investment and obviously you saw something worthwhile in the model or you wouldn’t have bought it.

The flat bottom for a tug bothers me though with your experience and some imagination you could create a sole plate, add frames, cover them and come away with a different model than you bought.

Check out some tugs on www.towingline.com

You will find tugs of various sizes and shapes.

Have fun!

My opinion is that is someone's attempt to scratch build a tug using their own idea, not from a kit or plans:
○ The deck's camber is too extreme.
○ The alignment of everything is poor.
○ The rise in the steps is not in scale with the pilot house's door height.
○ Filler on the hull at this stage of construction - not yet.
○ Lack of bulwark.
----- and more.

I would toss it - not worth the time.

However, I am glad you posted this. Great to see everyone's input when responding to unknown model boats. Thanks!

Lew
Florida ⛱️, USA

Added 16 Nov 23: At a closer look on my large screen PC I noticed there are a lot of pencil markings for cutting wood pieces which seems to indicate it was not a kit which usually has printed or laser cut edges. Crooked hatches on the sides, again with pencil lines. Might want to look closer at the alignment of the six port holes on the front of the structure. Notice the centerline? Not my cup of tea. Lew

The bottom is flat and is set up to use Schottel drives that came with the buy.
Rick

Again, with my little knowledge I'd reckon a harbour tug