Author Topic: NZ tug Koraki  (Read 19461 times)

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tug-arlyn-nelson

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Re: NZ tug Koraki
« Reply #15 on: August 01, 2015, 17:33:15 »
Skipper on the bridge of the Aucklander looks pretty salty with his white cap and lambchop whiskers.  Great looking tug!

VANYA

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Re: NZ tug Koraki
« Reply #16 on: August 02, 2015, 02:05:40 »
Steve.

I talked to a man....he has the drawings of the Aucklander.....he just has to find them.

The power of the internet!

Hayden
VANYA

sea monkey

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Re: NZ tug Koraki
« Reply #17 on: August 02, 2015, 02:21:26 »
Hayden: Small world! Love to get a copy of them. I've got a load of photos of the maker's model from the Nat. Maritime Museum and a few average shots from various sources. Almost enough to give it a go.
The Aucklander met a fate far worse than most old boats – ended up as a floating restaurant – and a pretty average one at that. Has had so much tacked onto it that it's now unrecognisable. looks more like a glasshouse on the dock.
About the laser cutting: if I was putting in a motor the ribs and keel would be "U" shaped and only about 10-15mm wide. They all fit together with slots and tabs. Even with half the number of ribs as on this one, the hull is surprisingly strong.
I usually leave enough room to put a floor pan in as low into the hull as possible. Can plan out exactly how everything will fit in. Can even line up how the shafts go through the ribs. Don't need great CAD skills.

sea monkey

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Re: NZ tug Koraki
« Reply #18 on: August 31, 2015, 21:15:50 »
Well, managed to have a mid-winter holiday and make some progress since the last post.
Attached the bulwark struts which I had laser cut. Very easy to drop them into the slots laser cut into the deck. The struts are 1.5mm ply.
Cut out the anchor well at the same time. Involved a little sanding and filling but now looks fairly seamless.


sea monkey

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Re: NZ tug Koraki
« Reply #19 on: August 31, 2015, 21:26:07 »
Also built up the roller deck. All of these components have been laser cut – much quicker construction, and more accurate than I could do by hand. Takes a little time to draw them up but seems worth it the long run.
The bulwarks are 0.8mm ply – much stronger that is looks. I give the exterior a coat of polyester resin for good measure. Seals it, fills any minor gaps and stops any flex in the ply. I use the same pattern technique as used for the hull sections to form the bulwark sections. As long as the lower edge is a good fit with the deck I can always sand down any excess at the top to make it flush with the top of the support posts. As you can see, the rough cut at the top is easily sanded down.

sea monkey

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Re: NZ tug Koraki
« Reply #20 on: August 31, 2015, 21:28:58 »
More of the same…
The bulwarks at the stern already have the freeing ports cut into them. Seems easier to do at this stage.

sea monkey

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Re: NZ tug Koraki
« Reply #21 on: August 31, 2015, 21:38:17 »
The complex curves at the stern are 2 layers of 0.4mm ply laid with the grain at 90Ί to each other. This is very strong. Individually the pieces are very flexible and can't stand a lot of handling, together they are very robust.

sea monkey

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Re: NZ tug Koraki
« Reply #22 on: August 31, 2015, 22:23:36 »
I got  preoccupied with the build at this stage and forgot to take some progress photos so the next images fast forward a couple of weeks. The capping rail has been added, the freeing ports are done. The real boat has very pronounced reinforced weld lines along the chine lines. I added these with half-round styrene. Hull painted, sanded, filled a few times to get rid of any blemishes.
Time consuming but that is where any imperfections really stand out. Don't look too closely.
Started on the Kort nozzles.
Attempted to draw them up in 3D but ended up needing a lot of help, They printed OK but the surface quality wasn't as good as I had hoped. I'll have to try Shapeways next time, their results seemed much better than the local result.
The nozzle supports are brass and styrene, brass shafts with outer sheathing of styrene.

sea monkey

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Re: NZ tug Koraki
« Reply #23 on: August 31, 2015, 22:25:14 »
And more...

sea monkey

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Re: NZ tug Koraki
« Reply #24 on: August 31, 2015, 22:27:50 »
Last of this batch.

mike_victoriabc

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Re: NZ tug Koraki
« Reply #25 on: September 01, 2015, 06:47:30 »
Looks good - interesting build.

sea monkey

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Re: NZ tug Koraki
« Reply #26 on: September 16, 2015, 16:17:46 »
Made some more headway. Restricted to working on it in daylight hours as I'm finding I can hardly see at night these days – even with glasses and strong lighting. Days starting to get longer now so that's working for me. Finished the hull. The chine lines have very pronounced reinforced welding lines. I used half-round styrene for these.

sea monkey

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Re: NZ tug Koraki
« Reply #27 on: September 16, 2015, 16:21:12 »
Fender housing from 1mm ply.

sea monkey

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Re: NZ tug Koraki
« Reply #28 on: September 16, 2015, 16:23:11 »
...and after a lot more sanding and a few layers of undercoat is was ready for painting. I kept finding imperfections after each coat of paint so the last round of filling and sanding took ages.

sea monkey

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Re: NZ tug Koraki
« Reply #29 on: September 16, 2015, 16:27:09 »
...and painted. I had made the bollards, deck vents, bitts, etc. between putting on the coats of paint. Also added some anodising plates to the kort nozzles. The real boat doesn't have them anywhere else on the hull.