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Tug Forum => NEWBIES - START HERE ! => : Toby July 28, 2018, 15:59:29

: Does anyone know the name of this girl? KEENOMA apparently.
: Toby July 28, 2018, 15:59:29
 Hello all

Does anyone recognise this girl. I have spent some time searching images online but so far I have not come across anything remotely similar to enable me to find out her name or to ascertain if there are drawings of her.

Thanks in anticipation

Toby
: Re: Does anyone know the name of this girl?
: ray28507 July 29, 2018, 13:21:12
hi toby  it looks like a canadian tug called keenoma  38inch long  a plan from traplet publications

http://www.traplet.com.au/keenoma-tug
: Re: Does anyone know the name of this girl?
: Toby July 29, 2018, 16:33:55
Hello Ray

Thank you so very much for your reply.  Yes, it certainly seems to be the vessel you cite. I note that the plan info it states that drawn is one tunnel not the two illustrated. I assume they meant funnel and interesting that my photo shows two with the superstructure centred between whilst on the plan it is likely that there is one funnel with the aft section of superstructure to the side.

Thank you again and well spotted. I will order a plan. I see these are available from sarikhobbies also.

Toby
: Re: Does anyone know the name of this girl?
: des July 29, 2018, 18:13:09
I checked the link that Ray posted, to Traplet.com.au.  I found that many of the click-through links went to Sarick in the UK;  then I noticed that there is more than just a casual similarity between the two sites, and the product ranges offered.  Also, many of the links on the Traplet site are dead.  So I don't know if Traplet are still operating in Australia, or if they are simply a local branch office for Sarik in the UK.

Des.
: Re: Does anyone know the name of this girl?
: Toby July 29, 2018, 18:28:34
Hello Des

The main link; I did receive an error message before getting to the page. I note online that others sell the plans printed to order.

Toby
: Re: Does anyone know the name of this girl?
: Toby August 01, 2018, 17:18:02
I have been in contact with Norm in Canada and also corresponded with Rollie Webb, the Vice- President of Robert Allan Ltd.

Mr Webb has suggested that the only tug of similarity to the enquiry is one built in 1974 named, Keewitan. It certainly looks as thought it ought to be excepting the beam to length ratio. Yes the model plan is a freelance 'based upon' but the side view and superstructure and funnels are a match.

Norm in Canada says it looks to be an ice- breaker with the type of bow it has. 

The original has three screws. The vessel remains in service.
Plans are available, according to Mr Webb, on payment of a fee to support the maritime Museum.

Toby
: Re: Does anyone know the name of this girl?
: Toby August 01, 2018, 17:24:48
I think there is certainly variation between the pdf of the real vessel and the online preview image for the model plan.

It certainly looks more solid and powerful with the broader stern and general beam.

Toby
: Re: Does anyone know the name of this girl?
: des August 01, 2018, 22:54:30
Nice looking boat.

I've found that there are often discrepancies between a vessel's published plans and data sheet, vs the real thing.  Often this is brought about by through-life changes.

Des.
: Re: Does anyone know the name of this girl?
: Toby August 02, 2018, 03:13:07
Hello Des

I think that in this instance the model is a 'made up' boat  with resemblances above deck to the real vessel. The real vessel had a draught of 2 meters and clearly the hull shape is rather different. The vessel remains and I have found a few interesting photos. Nothing of below the water line yet. 

I have just received a moment ago an email from Mr Allan and he suggests that the similarity is but only the deck house. So we all seem to agree.

It has been interesting and educational.

Which is your preference Des; model shape or the full-size vessel shape?

Toby
: Re: Does anyone know the name of this girl?
: des August 02, 2018, 15:05:42
Well, I like to have as much info as I can get first, including underwater details if I can find it without too much hassle - not always possible if I'm looking at a boat built in the 1970's.  But as you've noticed, even builders plans don't always match the real boat, even at delivery.

After that, I'll look for a commercial hull that is close - I can always cut away bulwarks and transom, or lengthen a hull (shortening is not always possible);  but I can't do anything about width or bow shape.  If I can't get a hull close enough, then I'll work up a set of drawings so I can build my own hull - which will almost certainly include some sacrifices in order to make the hull easier to build.  But I would certainly include such obvious features as bow thruster, bilge keels, or hull openings for "box coolers".  See the example I've posted - this represents a Burness-Corlett designed "hydroconic" tug of the 1970's, but even now, getting hull details is difficult, so I've had to basically start with a clean sheet and not much more than a "mental image" that is 45 years old.  And building a model using a commercial rounded bilge hull is out of the question since the hard chines were such a feature of the B-C hydroconic hulls.  (Thanks to Steve, Sea Monkey, for reviewing my initial hull lines drawing for this hull.)

Topsides are relatively easy, but sometimes deck machinery can be a challenge.

Des.
: Re: Does anyone know the name of this girl?
: Toby August 24, 2018, 07:43:46
Well I bought a second- hand hull and am using the plan sheet above.
I note that the plan allows either for a single screw out of the skeg or for some of the skeg to be trimmed away and twin kort nozzles to be fitted.
I have bought a pair of 11" shafts and 40mm props from MBB and decided to try the kort nozzle set up.
I have trimmed the skeg and positioned the nozzle shaft tubes and inserted the prop shafts.
There seems to be no provision for anchors and so I have decided upon cutting the hull to insert an anchor housing port and starboard something akin to that of the tug pictures above.


Re the kort nozzles would someone kindly tell me whether or not these are set straight back to the stern or are they 'flared out' (or in) for the boat to steam ahead.
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: olscuzbut August 24, 2018, 09:58:55
Hi Toby,  If I understand you correctly, any Kortz that I have seen are flared out at the leading edge tapering narrow at the trailing edge.  Not sure if I sent you the pics of the one I built but will include it here.

Norm
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby August 24, 2018, 10:07:58
 Norm thank you for the photo; it was not one I had seen.
So if I comprehend aright then the kortz at the propshaft end is of greater diameter then at the very stern.

In addition are the nozzles themselves set true to the  line of the theoretical keel spar or are they set slightly turned out each side

Toby
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby August 24, 2018, 10:12:55
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: Re: Does anyone know the name of this girl? KEENOMA apparently.
: olscuzbut August 24, 2018, 11:59:10
Hmm!  Good question  Toby.  In my kit built Smit Nederland they were strait in line with the keel.  On my stormforce tug I made them the same. (in line with the keel)   These are my home made ones.
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby August 24, 2018, 14:33:50
  Norm,

Great looking job!!  Very  neat and crisp.

Toby

: Re: Does anyone know the name of this girl? KEENOMA apparently.
: des August 24, 2018, 15:34:28
Hi Toby

The Kort nozzles have an airfoil cross-section, usually thicker at the forward end and thinner at the outlet end (although there are some exceptions); flat in the area of the prop ring - the smallest internal diameter of the nozzle is in the region of the prop ring itself;  the nozzle then opens up slightly towards the outlet, thereby forming a venturi shape.  The outer surface is always tapered down, in a straight line, from the greater diameter of the leading edge, to the thinner diameter of the trailing edge;  this shape promotes laminar flow of the water over the outer surfaces of the nozzles.  (The nozzle is never partially flat and parallel, and partially tapered, as seen on some freebie model plans.)

There are two different airfoil shapes in common use for fixed or steerable nozzles (not sure about Schottel drives though) -

- one airfoil shape is used when thrust is most usually required in one direction only (usually forward) than the other - eg for towing over the stern, or pushing with the bow.  (I would think that this is the nozzle shape most likely to be used for Schottel and other ASD drives.)

- a different airfoil is used if the tug is of a type which can equally tow over the bow while travelling backwards, as well as towing over the stern.  This nozzle is not as efficient as the first when towing in the principal direction, but is more efficient in the "other" direction.

The internal diameter is never less than the tip diameter of the prop, so as to allow the prop to be withdrawn out the aft end (after the rudder has been removed).  In practice, some clearance is required, so in most model setups the internal nozzle diameter is usually 2-3 mm greater than the tip diameter of the prop - this makes for some interesting considerations when trying to source compatible props and nozzles from different suppliers, as some manufacturers of both state true diameters, and others state "nominal" diameters.

The nozzles are always set parallel to the shaftline - this is a matter of physics and fluid dynamics, as well as the need to maintain a constant propeller tip clearance within a narrow space.  Canting of the nozzles relative to the shaftline will decrease propeller tip clearance in one region, while opening it up in another, thereby resulting in vortices forming in the water flow through the nozzle.  If the shaftline itself is set running in or outboard, then the nozzles will be set accordingly.  Similarly, if the shaftline is set running upwards or downwards, then the nozzles will be set accordingly.  (I am currently working up working plans for a model where the prototype tug's prop shaftlines run both slightly downward, and slightly outboard.)

Hope this is helpful.

Des.
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby August 24, 2018, 16:59:41
Hello Des!

Wow, what a lot of useful and interesting info.
Thank you.
I shall re- read it for kort nozzles are not something I have dealt with before and this all quite new.

Toby
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby September 25, 2018, 10:32:22
Work on my model is progressing:

Keel primed and painted

the ice breaker bars at the bow added.... made and shaped in wood and coated with finishing resin...

Shafts in and  exit housing about them on the outside of the hull made by gluing a plastic washer to the shaft at the approoriate point and then filling behind with p38 filler and shaping  followed by a coat of resin.

Forecastle and hawse pipes and anchor housings installed.

Decks and bulwarks finished but for a few bulwark supports.

Diesel stacks made and painted and a few deck fittings organised.

Working on the wheelhouse structure and wondered if anyone had ideas about kitting out a fairly modern type of wheelhouse.  How have others improvised those various items of controls and electronic gadgetry.

Toby
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: sea monkey September 25, 2018, 21:23:38
Any photos?
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby September 29, 2018, 01:29:02
 Have been trying to upload photos  but keep on getting error message.
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: des September 29, 2018, 04:16:15
Hi Toby

You'll probably find that the photos exceed the forum's file size limit.  There are a number of free utilities available from the web you can use to re-size the photo files, or I just use Windows Paint.  I know other members use Photo Bucket, but I don't know how this works.

Des.
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby September 29, 2018, 06:10:00
Deck etc is just first coat of grey and yellow.
 A bit of tidying up to do.
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby September 29, 2018, 06:12:06
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: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby September 29, 2018, 06:16:23
 The arrows point to where plastic washers were glued on to the stuffing tube behind which filler used to shape the housing required.
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: olscuzbut September 30, 2018, 06:00:32
Looking very nice Toby.  Just wondering if you will experience any cavitation problems as it looks like your props will not be too far below the water line.  Or maybe that is just how it appears in the picture.  Will be watching for sea trials.

Norm
: Re: Does anyone know the name of this girl? KEENOMA apparently.
: Toby September 30, 2018, 06:26:38
Norm,

I will have to look at that point you raise, when I return home.
I don't have the basic plan sheet to hand.

T