Last year I did a lot of looking for a new project. I had long lusted for a challenging, large semi-kit for a truly interesting ship. I found Barracuda RC Boats semi-kit for a 73" long tug hull, but with an amazing twist...this was for a near-scale hull for the very elusive Ulstein X-Bow.
Barracuda owner Alex Steen has taken the only publicly available information non this hull, directly off of Ulstein's public patent application for the SX-157 hull design, and translated it into a laser-cut kit in 1/48th Scale of a proposed "ALP Future" design for this hull. The kit is simply amazing! It arrived April 10th, and was the first model Alex cut using his new machine.
Understand that there is absolutely nothing like this available from any other source I am aware of. When the kit came, it was staggering to unpack it...
I referred to this as a semi-kit because it only provides the hull frames, and all plywood cut to build the bare-bones superstructure. The hull is planked with 1/8" balsa. I elected to use wide strips, as I have the means to very effectively steam them. Each plank got 30 nminutes in the steamer along with 3-4 kitchen towels. I fit and clamped the hot plank in place, then laid the hot, wet towels on top, with weights on top of that. Once cooled, I could easily epoxy them into place.
The entire hull was faired using bondo, then fiberglassed with 4 OZ cloth, and four coats of West Systems epoxy resin, sanding between coats. I used Krylon primer and paint throughout.
I took a lot of liberties building this using parts I could make, or buy and easily adapt. The propulsion system is a good example. I bought a pair of 4" Kort Nozzles with twin rudders from Harbor Models. Each has a 3 1/2" four blade bronze prop made for a Kort. I made the prop struts and thrust tubes, aligned everything to give me clearance inside the hull, and epoxied everything into place.
I powered Nostromo with a pair of Harbor Model's belted reduction motors, originally on 40 Amp ESCs. I later downgraded them to 15 Amps instead.
Electrically, Nostromo has both 12 VDC and 6 VDC systems. I used pairs of sealed lead-acid batteries which fit well and helped with some needed ballast.
Speaking of ballast, Nostromo draws 5 1/2" of water, so it took considerable ballast to get there. With the batteries she weighs about 50 lbs, and it takes another 70 lbs of lead shot (in 5 lb bags) to get her to the Design Waterline.
I'll add some more pictures as time goes on. This has been such an amazing project, and timely as well! We're already drinking whiskey like vaccine, so I feel fortunate to have something else to concentrate on for the past 4 months.
I am using an 8 channel Spektrum radio, as the Rx gives me 3 Aux channels to use and program.
Throttles are on Throt and Aux 1
Rudder is on the Aileron channel so I can steer without jogging the throttle.
Aux 2 controls the Bow Thruster
Aux 3 controls the Aft Thruister
Future plans include a fire pump and working fire monitors, likely run off of the landing gear channel....
She also has operational running lights, mast lights, main winch room lights, operating mast radar, and capability of installing a remote TV camera system. A boat like this one is never done....
barriew Captain (moderator)
Posts : 2631 Join date : 2011-11-26 Age : 83 Location : Thaxted, Essex
Subject: Re: Nostromo: 73" Anchor Handling Tug, Ulstein X-Bow Sat Aug 15, 2020 6:42 am
Hi Bob - thanks for posting this. Just a little tip. When posting your pictures from Servimg select the middle line and the actual picture will appear in the post not just the link.
Barrie
Bob K likes this post
Bob K Deck Hand
Posts : 9 Join date : 2020-08-14
Subject: Re: Nostromo: 73" Anchor Handling Tug, Ulstein X-Bow Sun Aug 16, 2020 12:57 am
Thanks Barrie, let me try this again....
First view of the trial fit for the screws and shafts to make sure the props had clearance inside the Kort nozzles. The stern is very rough, and made from 1" pink construction foam. You can see the roughed in keel bilges I added as well.
It took weeks to get the hull to this point. I gave the fiberglassed hull 3 coats of Krylon gray primer, 2 coats of Krylon Satin "Pimento" for color, and 2-3 coats of satin clear. It produced a nice tough finishl
The only glitch is that those KIort nozzles extend 3/4" below the keel. I solved that by installing a keel block on the workbench, to protect the nozzles.
This one is kind of ugly, because it was taken during ballasting. I built a tank out of 2x8 lumber & lined it with plastic to float the hull. It took 15, 5 lb bags of shot to get her level and near the design waterline. The hull draws 5 1/2" in ballast.
To protect that balsa hull and support all of that ballast, I cut down pieces of fiberglass cloth, and using West Systems marine epoxy, I glassed in the entire interior hull. Then I cut pieces of pink foam to fit between the ribs, and Gorilla glued them into the hull. Its as solid as I know how to make it, and I'm not worried about bumping the dock with 140 lbs of mass, and cracking the hull...
The blue area between the motors is tape protecting the ESCs which are epoxied to a 4x4 piece of aluminum heat sink. Each motor has a modified heat sink epoxied to the can with a pair of small 6VDC fan motors on each side. In the center rear is the blue motor for the aft thruster, and on each side are the two rudder servos.
I am running 2 rudders on each servo so the are well balanced. I found inexpensive all metal gear and aluminum bodied servos up on Amazon, along with the fancy blue crossbars and hardware. After sea trials, I've decided I will need to either make these rudders larger or make new rudders all together. Even with four rudders, the hull turns a bit slower than I like. Bigger rudders should fix that...
Understand, that there are absolutely no instructions on how to do any of this that come with the semi-kit. All you get is the bare hull and superstructure, so beyond that you are on your own...that's where I found a lot of fun with this project.
Bob K Deck Hand
Posts : 9 Join date : 2020-08-14
Subject: Re: Nostromo: 73" Anchor Handling Tug, Ulstein X-Bow Sun Aug 16, 2020 1:01 am
The black material in the back of the hull is permanent ballast. I mix epoxy resin with #8 shot, and poured it into those small spaces along the inside of the skeg and in the stern. It still gets 25 pounds of removable shot bags for sailing....
Full Ahead likes this post
Bob K Deck Hand
Posts : 9 Join date : 2020-08-14
Subject: Re: Nostromo: 73" Anchor Handling Tug, Ulstein X-Bow Sun Aug 16, 2020 3:06 am
Here are a pair of links to the primary sources I used to create my version of Nostromo.
The first is a theoretical model of the Ulstein X-Bow hull that was used to create the semi-kit.
The second link is a multiple image photo study of the MV "ALP Striker" that was taken while the vessel was at anchor in Singapore. I was particularly fascinated by the extensive winch command and control system built by Rolls Royce. The winches on Nostromo are painted as close as I could get to Rolls Royce blue, and by next Spring Nostromo will be sporting a prominent "RR" logo on each side of the winch house.
The helo deck is my design, built with Plastruct girders and parts. It has functional landing lights that will be lighted by next Spring. I hope to conduct some flight ops with local drone pilots...
I engineered this model as I went. Those winch rooms and reels are my version, and certainly not the only version that could be built with this semi-kit. If ever there was a kit meant for an advanced modeler, this is it. This baby consumed my workshop for almost 4 months straight, and was not cheap. The value is amazing, as it never fails to impress people down at the local boat ramp when we launch and recover this enormous rascal. It really is almost the size of a small jetski...
OBTW....please note the SpaceX Starlink antenna on the Port side of the pilot house......
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