F48 Build

Hi. So here is some stuff on my F48 build that is in progress. I building based on the Ghost Train hulls. I am located in Austin, TX

This is similar to the boat being built in this thread Ghost Train, texas style build thread. My hulls were even cut on the same templates.

I have pictures and documents available on my F48 Sky Drive folder. I will be adding pictures to the folder as work goes on.

Hulls are built as fiberglass over foam. The outer hulls are 3oz on the top and 2x layers of 1.5oz all the way around. Layup for the center hull is TBD.


Good to hear of another being built here in the U.S.

Class really went stagnant for several years, and of course the airline industry travel issues after 9-11-2001 didn’t help the cause either.

Looks like I might have to dig and empty my closet? :rolleyes: :cool:

So here are a few questions I have received about the boat followed by some answers…

  • How did you determine where on the float hulls to mount the foils (simply the mid-point?)

  • In the same manner, how did you figure out what angle to use and what is that particular angle of the foils relative to the float hull center line?

  • What material comprises the foils construction?

  • Type of foam used for hulls

The location of the foils is based on what I have seen in pictures of various boats online. I have some of the pictures in my “Ref Media” folder in my sky drive, but most are not. That folder was an idea that came after I had done a lot of the initial research work. That and what “looked right”. A lot of the boat is just “what looks right”. I don’t have my notes for the exact position in front of me, but it was near the midpoint.

The foils are CF helicopter blades. Very stiff, thin, nice and light, and seemed like a good fit for the job. The blades I am using are from here. The mount for the foils is such that I can adjust the length to play around with it.

The foil is angled inward by 50* in relation to the hull. The hull will be angled out by 14*, so it results in the foiling being angled in by 36* from the overall boat. This again what just what I thought “looked right” after a few mock ups.

The foam is white EPS, not sure of the weight, but light whatever it is.

I have been intending to better document the specifics of the build, but it is enough to just get work done on the actual boat… Taking pictures is something that I will continue to do as work moves forward regardless.


I have a few more pictures posted on my sky drive project folder. Mostly they are of the internal structure details of the main hull.

The first “Nightmare Mk.VIII”-Prototype has completed its maiden voyage!!!

Here is my communication with Phanchita from Thailand + first pis:

Good morning Ernst,
enclosed two pics to make you happy too. I just came back from the maiden voyage of the Nightmare MK8. I heard a lot of Ahhh - Oooohhh and Uuhhhs from the spectators who tried to catch some fish for lunch…
The MK8 is very sensitive on the rudder - too sensitive. I will try again with my computer transmitter and lots of expo. It tries to pitchpole like all tris do- today with gusty winds at about 4 to 5 bf I couldn’t get it to pitchpole - it would have be no problem for my Triton. I could submerge it to the mast
You can see the wind when looking my Marblehead with the same rig.
I tried to get it on one hull - the rig is a little bit to small so I only managed it in some gusts but it works…with the help of huge rudder which is too sensitive - it works like an elevator on aircraft it can lift the main hull off the water on one hull and easily puts the tri back to two hulls. I need to practice a lot to control it perfect but the design itself is much better and forgiving than the others I sailed. I will put some small video clips on my website by the evening.
I had some time at work to search the forums - all these guys talking so bad about your designs but no one ever build as I see. I suggest you let those guys talk what they want as you have done a design which works. You can show anyone who wants to know the clips and the pics now.
If you want I can put the MK7 or the MK8 plans as a free download on my website too…
Have a nice weekend

Dear Phanchita,
I have no doubt it will work out perfectly!

And I have 100 % confidence in your skills - building AND sailing.
Buddha is a friendly man - why shouldn´t he smile at you?
You are doing the right thing at the right time.

Have a nice day

Dear all multihullers,
I have built the Nightmare MKVIII on the pictures in the last post
anyone want to see videos they are at YouTube.
Comments and new ideas are most welcome.




Happy Sailing

The following email reached me tonight:

Hello Mr. Ernst!

Remember me?

I was just on RC Universe and saw your posts! It looks like you have quite a crowd after your free plans!! What’s the possibility of sending #89?

Best Regards!

Mark Baldacchino

My answer:

Hello Mark,
of course I can remember you!

But you cannot get Plan No.89 - it has to be No.92 by now!

Mark Baldacchino was the USA citizen with the first Nightmare I had designed and sent as a kit to the USA -…- in 2001

Another F48 to add to the list of builds.
-Center hull is balsa planked, pink foam deck, carbon tow for panel stiffness and torsional strength. 1.4 oz. glass inside and outside.
-Floats (started) will be solid pink foam


  1. What are guidelines for hull alignment? Floats towed in or parallel?

  2. I intend to use straight 1/2" carbon tubes for beams and mast. Is this good strategy?

  3. I intend to use spectra for all fixed and running rigging because it can be easily spliced and glued for light, simple, and cheap. Is this good strategy?

Hi and welcome to the class !

You are near my home town of Saginaw ( well, sort of) and there is another sailing F-48 in the Cleveland Ohio area (Clyde Jones) who pops in here once in a while.

Which design are you building to?


  1. What are guidelines for hull alignment? Floats towed in or parallel?
    I would suggest parallel if you are out to maximum 48 inch beam. If you are running single rudder - you are OK if running rudders on each float, thos can be towed in slightly and be aware of “Ackerman Steering” issues with two rudders in different sized arcs of a turn.

  2. I intend to use straight 1/2" carbon tubes for beams and mast. Is this good strategy?
    Mast “might” be good - but I would consider a 5/8" diameter at base. If you can purchase taper, you will need to know and measure luff curve for leading edge of mainsail so it aligns with mast bend. For cross beams, if you use 1/ inch you are really at the edge of performance. (I used them on my 1 Meter trimaran and in strong winds can see slight deflection. What yo "could do, is consider buying some 1/8 thich birch multi-layer good plywood. Cut a strip thin enough to slide inside the beam and let epoxy run down to glue strip to inside of carbon tube. Once glued on both edges and each side, align the plywood internal strip vertically when installing. This added strip will take up a great deal of the bending load you may experience without the strip. Kind of acts like an internal “Dolphin Striker” - and of course, you could also add external striker under each beam like a beach cat uses - although it is more windage and prone to striking wave tops and slowing your down.

  3. I intend to use spectra for all fixed and running rigging because it can be easily spliced and glued for light, simple, and cheap. Is this good strategy? Most definitely - alternative is stainless steel fishing leader with crimps from local fishing store. Look for something in the 80 lb. test as minimum. BTW - one guy is using Kevlar thread, embedding in deck and using in place of screw-eyes for standing rigging connections. You can usually find at a place that sews carpet - or tarps and catamaran trampolines. Knocks off weight from the stainless fittings and will take paint like rest of hull/deck, yet remains flexible.

Good luck with the build - maybe time for me to reopen the old F-48 Class promotions and get owners registered so we know where they are.

Thanks Dick for the great advice.
My design is my own, and not terribly scientific. I do have some aero and hydro background and am applying basics along with tons of web research, which is probably the most fun:)