OK, I know this isn't really a warship because it is unarmed, but I am so pleased how it came out that I wanted to share it. I made a 144:1 scale model of YTB-142, the Nokomis, a Woban class district tug. At 100' it comes out to just 8.3 inches long and 3.9 oz total weight. I started with a fiberglass hull and added a small brushless motor, 10 amp speed control, small servo, receiver, and 1/2 oz of ballast. It does float on its scale waterline. I took it out on Sunday and ran it around the pond a little. Anything over about 1/4 throttle just made the prop cavitate, so it was very over-powered. With the way the prop is setup and the large rudder, it will turn 180 degrees in about 2 ship lengths. I hooked up a line to my Roanoke and towed it around. It didn't tow it very fast, but this little 4 oz boat did pull an 11 pound ship. Mikey took some photos, so when he gets them posted I'll add them here. The entire superstructure acts as a recovery float, with a winch for the line hidden inside the hollowed out back. The deck is held in the center by one super magnet. The straw that holds the superstructure on also doubles as a vent, for when I (hopefully) get the deck sealed. The inside is tight, but not too bad. I have a two cell 300 mAh LiPo battery to supply the power. Since full throttle is about 0.3 amps, I should be able to run it for an hour or more on one charge. I did cut the windows for the penetrable area (only one 1/4" rib) and covered it with balsa so that I could run it in combat. But after running it around, I changed my mind, since any hit would probably knock it right over. Oh well.
Impressive. Very impressive. All you need is a pump, and you'll be all set. It's a pity that tugboat gets its stability from beam, not depth. If it were deeper and skinnier, you could make it self-righting, like those USCG surf boats. Now wouldn't that be cool?
Very cool little boat. Watch the lith/po as I think that's one of the ones that goes BOOM! More stable than lithum but not stable like lith/fe (iron)
Here's a picture of the tugboat pulling the Roanoke. It didn't move very fast, in fact it was probably about scale speed.
question: when you were pulling the Roanoke, were you still able to steer? ie could you pull the Roanoke where you wanted to go even if it wasn't initially facing the right direction?
I was able to pull the Roanoke in a complete circle, but it was a fairly big circle. Maybe if I had someone on the Roanoke's rudder it would have worked better. At one point I was about 45 degrees off the beam and the tug was just churning water, so making it turn was not easy.
If you actually want to use it for a tug's design purpose... you want a very large low pitch prop for better thrust at low speed.
Actually, guys in the WWCC have been trying to create a "ship recovery device" for years, because recovering disabled (but not yet sunk) ships after battle in a timely fashion plays an important part in our regular sorties. After 15 minutes of combat, the CD calls "cease fire", and then everyone has 5 minutes to return to their team's home port. If they don't make it, there's a pretty big point penalty, so we get lots of practice playing bumper boats to get the ones with moss or electrical problems back home. Several guys have actually installed launchable tow cables on their ships to aid in recovery, but in every test the force required to pull a 45lb battleship at even a slow speed is greater than the turning force of the towing ship's rudders, and leaves the would-be rescuer stuck in a straight line.
Some good tugboat/minelayer plans on the French navy site... look for 'Actif', she was an oceangoing tug that laid mines.
The tug is not commercially available but the plans are free. I built the tug from original Navy plans available at http://www.hnsa.org/doc/plans/ytb142.pdf . I drew up the plans in CAD and then cut the plug out of foam on my CNC machine. From the plug I made a mold and then layed up a fiberglass hull. I'll have to check out the tug on the French website and add another couple of MB of files to my computer. Plus, with the popularity of French ships in my area, I should be able to sell some kits if I model one them.
Try and find one that is relatively deep and narrow. Ships like that are much more resistant to tipping, and when built properly they can actually self-right. I've seen too many small transports accidentally ram-sunk by a minor bump, because they couldn't self-right.
RCENGR you sure do have some good ways of doing things and interesting projects. I always enjoy seeing them. It is good to have you here. And on the tugboat, that thing is sweet any chance you would post the cad you made for the hull in case some others of us would like to make one?
I would be glad to share the CAD file. The file manager didn't like the .dxf file, so until I get my website running or think of something else, just email me if you want a copy.
heya Mark, Is the Nokomis available or did you do her on your own, cause if she was i would love to have one two! can you used rechargeable battery for her or no? Nikki
Nikki - the tug is not available as a kit, it is something I scratch built. I do have rechargeable batteries in it, they are 2S 300 mAh lithium polymers.
