LARA 1969 by Elder_dumpster- Trident 24 centerboard sloop - RADIO - My first scratch POF model of a yacht I used to own.

[Elder_dumpster]

I am about to begin building my first scratch boat. I was looking for a sailing boat kit that I could add RC to. There are some in the Krick range and I nearly plumped for Ariadne, but was wavering at the required skill level and cost when my son suggested building a model of our old boat that we had when they were kids. Brilliant! I knew where to get plans and have an intimate knowledge of every detail I'll need to pull this off.

 

I contacted some old pals in the Trident Owners Association and within a day, had full lines, construction, section, sail-plan and other original drawing scans. They are at the scale 1.5 inch : 1 foot (1:8). The boat is 24 ft LOA so after converting that to metric, I'm going to end up with a model around 940mm LOA.

I think that will be ideal to house RC and for her to sail in reasonable winds. I'll need the equivalent of 760 Kg of ballast in the stub keel (94 Kg to scale..I assume mass has the same ratio as linear measurements when converting for a model ? ) the rest of the 5 tonne displacement will need to come from the construction materials, RC and running gear, batteries and probably some lead shot in strategic places.

The original boat was GRP with plywood bulkheads fore and aft of the deck-stepped mast and fwd of the transom. I'll add frames at most stations from something like 12*5 mm strips. The point of the bow fwd of the accommodation will be solid balsa. I'll plank with whatever is reasonable and available at the time, then cover the hull in several layers of fibreclass cloth and resin... at least they are the sketchy current plans..

 

Lara was 91 out of 248 Tridents built. Sadly the person I sold her to, abandoned her and she just rotted away as far as I know. I am actually still trying to find her after a last sighting 'in a sorry state' 10 years ago. Whatever the outcome, Lara will live on in this model.

 

It isn't going to be a quick build I'm still working in parallel on a CUX 87 kit, I work full time and have a family, so don't expect many updates for a while.

 

Plans and photos attached.

 

sections.pdf 1974marconbrochure.pdf linesmall.pdf

[FreekS]

Hi great looking boat. Note the ballast scales to the power 3! So your 940kg ballast becomes 1,5kg at scale 1:8!

 

you need to get that weight as low as possible in, or even below the keel with a “false keel”. See my Corsaro 2 build log for example. You also need to build the whole boat and especially the rigging as light as possible!!

 

ill definitely follow this!

[Ian_Grant]

Elder,

 

Any sailing RC model has to be designed with the "scale problem" in mind.

 

At 1:8 scale you have a hull 1/8 as long, with 1/8EXP2 ie 1/64th the sail area, and 1/8EXP3 ie 1/512th the displacement. In other words you have 8 times the sail area relative to the displacement, with all the negative implications on stability. This is why scale sailing models almost invariably have fin keels with a streamlined lead-filled bulb on the end. Some builders make the keel detachable for transport and/or for out-of-water display.

 

I'd be very surprised if your model would be stable if faithful to the original hull, even with the tiny stub keel crammed with lead. I highly recommend the soft-cover book "An Introduction to RC SCale Sailing Models" by Phillip Vaughan Williams, which covers all aspects including stability, hull making, rigging, and sail winch control systems for even the most complex full-rigged models.

 

Look forward yo your build!