Multihull Structure Thoughts

If I remember correctly Gary has an affection for Belgian Blondes amongst others.

 

Todays Gary Baigent item is about Gary’s designs for others. Gary has a friend called Jacques who Gary has sailed with and has helped Gary over the years. Jacques has a modified plywood Farrier 680 or 720 Trailer Tri and wanted something a little faster. Gary did a preliminary design called 3 Devils for him.

3 Devils is a larger (but not by much) Sid main hull and with conventional beams, long floats layout, conventional wing mast/soft sail rig; foils in the long floats. 3 Devils is 26.25 x 26.25 foot and was proposed to weigh 620 lbs all up. The wing mast was proposed to be 37.7 to 39.6 foot high with a high aspect ratio mainsail (about 4 to 1), this implies about 350 square foot of wing and mainsail. The length to beam on the main hull is 15 to 1 and on the floats 26 to 1. The draft over the float based angled foils and rudder is about 5 foot.

The accommodation is only minimal with bunks for two adults and low headroom with some storage because the tri has low freeboard to reduce weight and windage. This is a very high performance day sailor tri with limited cruising ability.

The build was to be 4 mm ply as there is less curvature in hull than Sid, which needed 3 mm plywood to handle for curves.

Next design came when James Burwick, an Englishman, asked for some sketches and ideas for an around Round Britain race trimaran foiler. The 36 x 36 foot tri was to suit an Englishman who was going to have the tri built in France. The tri was to be built in carbon fibre, foam, carbon fibre and epoxy with a lot of high tech light weight fittings etc. The tri was to be an “expanded” Sid. The main hull length to beam was about 17.5 to 1. This tri was to have some accommodation for 2 but still minimal headroom. Not much is known about the rig or foil configuration and even if the tri was built.

Finally, Gary had a potential client who wanted a 10 meter cruiser. Gary did a sketch of a design he called “Cruise missile”. This was a blown up Sid with full headroom, a schooner wing mast rig and higher, slightly fuller floats but still had foils in the floats and a T foil aft. The draft over the central hull daggerboard was 6.2 foot. Very little is known of this design as I think it was at best a design study.

Gary did several other designs from his CoxBay skimmer, a wide monohull day sailor with a schooner wing mast (300 x 100mm section) rig that carried 225 square foot of sail all up, to a very good small tender he built on request. His 2014 project to keep him amused was another monohull of 19 foot (Frankham580) where the customer was to help him build the design. All these craft are very interesting and it is a pity that he did not become a full time designer as we all could have seen a lot more of his boats on the water.

The jpegs give and idea of the tris and the CoxBay Skimmer and Frankham580 hull lines.

 

Oldmulti,
I'am glad that he has not set sail for his great last journey. Gary, sail around the bay a loooong time. Cheers!!

 

I would have loved to have met Gary when I was there with my proa. I was on a mooring in Devonport for months, but never knew about him until after I returned home.

 

Gary is an outstanding builder/designer. Unfortunately, I have found only building, mooring and very light weather sailing records of his designs !

 

Now we get to Gary Baigent latest high performance day sailing foiling camp cruiser. It started as a concept in 2015 under the name of “Lethal Insect” then changed name to “Sid 650” and finally was named “Frog”. The first 2 jpegs will show the 2015 conceptual drawings which was a Holtham foiler concept and had some first cut dimensions of 21.3 x 23.3 foot with a guess weight of 315 lbs. The wing mast height was to be 31 foot with total sail area of 215 square foot with an optional 75 square foot reacher. So how did the initial conceptual drawings turn into Frog. We now get an insite into Gary Baigent's mind and build approach. Remember this is Garys third tri with many modifications and rebuilds done on the previous 2 tris over 30 plus years.

This item will focus on the build of Sid 650 and some of the design decisions. Tomorrow we will focus on Frogs development from launching, rig and foil development to its final sailing mode as of 2021.

The third jpeg give the lines of Sid 650. The concept was at that stage 21.3 x 23.6 foot and a weight of 335 lbs and a proposed displacement of 595 lbs. The mast was proposed to be 29.6 foot long with a 1.2 to 1.3 foot section. The initial proposal was to have a rotating main beam like Scissoring Sid for trialability. Foils and rudder yet to be determined. Next you need a building shed, simple, punch a hole in either end of the existing shed so it can be built “under cover”.

You have the proposed lines and you start to build the main bulkhead ring frame which is used to help shape the rest of boat. Cut down timber for the 20 x 20 mm keel line the prepare the 10 x 10 mm gunnel stringer lines. Cut out your transom and stem then eyeball the shape to approximate the line drawings. Put in a few bulkheads and bog/glue together the basic frame shape.

Now the real skill learnt over years is applied. Take your 3 mm good plywood put epoxy on one side. Garys words: “Before I stapled/glued the two long ends of plywood to the keelson, waited or heated it to cure, epoxy coated the inside, then bend the plywood each side down to the hull/gunnel shape. Because it has to be bent to get its amazing rigidity, (glass/carbon/epoxy added later) the ply has to be around 3 mm.” The shaping of the plywood takes time and care but the overall process is fast.

The jpegs of the hull show how good a shape you can achieve but the real work starts when you have to put in internal structure floors, daggerboard and rudder cases. The deck beams are light with a light plywood deck.

The original main box cross beam was built to be “rotating” for sailing but after working through the beam rotation bearings etc Gary decided to have a “fixed” crossbeam structure. Again, the box beam had 2.7 mm ply fairings on a light framing structure.

Next came the first cut of the foils which had changed from the Holtham plate foil concept to the Sid style of shaped lifting foils attached to some very small floats.

Tomorrow we will talk about the launch and initial on water experience. The jpegs give the idea.

 

part 2 of Frog (650) build jpegs.

 

how does the rudder rotate? It seems to be in a fixed slot?

 

Tane its a 2 part rudder the top part is fixed then the bottom part turns. When you raise the rudder in the slot you have to have the rudder turn part in the same plane as the fixed part. See the jpeg.

 

Gary Baigent built Frog from about 2017 to 2019 with other minor delays getting in the way, eg looking after Sid and Groucho, hosting several international guests, co authoring a book, writing magazine articles, being interviewed by the press, designing other boats, helping build some other boats, oh, he was also working full time whilst doing photography and being part of exhibitions. In his spare time he liked to dive, do cray fishing, enjoy the company of his mates and go sailing on friends boats. Just your average person.

So, Gary launched Frog with a fixed cross beam after rejecting the rotating cross arm idea. Next he he put on very small floats and foils he thought would support the rig. He found after the initial launch he needed fenders under the foils to protect the foils when on the hard and help stabilised the tri whilst moored.

After creation of the mast which had a fat trailing edge (D shape) 2 mainsail were borrowed from the CoxBay Skimmer to form a “single sail” about half the intended size for testing. Quoting Gary: “Increased float size on Frog, still small but maybe an improvement because the boat was too tippy at rest. Going to test sail the double luff main by using the two Skimmer mains as one sail on Frog; will be too low for the D mast but will give an indication of how the full sized sail will work. Will bodgey up some string attachments or sliding pins to the main battens at leeches.” The second modification was waterstays to help support the crossbeams whilst sailing.

After the float size was increased modifications were done to the foil shape size and position to improve the sailing characteristics. The overall beam of the crossbeams is 23.6 foot but the overall beam including foils is 24.5 foot. Gary again: “The beam on main hull is at the halfway mark, 10.7 foot and then rakes forward so the foils are positioned maybe 250mm or so forward of central position. I like the security of not burying the main hull bow from tripping.”

The floats size needed to be increased slightly again. Now the “concept” was proven Gary paid for new mainsails for Frog and went seriously sailing. The final D mast was about 30 foot high with a 1.1 foot D section carrying about 210 square foot of sail. The bottom foil has an angle of attack of 3 degrees, the higher foil sticking through the float has an angle of attack of 6 degrees for more lift if required. Gary as of 2021 was still refining foils, angle of attack of foils and rig tuning. He was also preparing a rebuilt Groucho Marx for further sailing with a recently built replacement wing mast. Why do I feel so inadequate.

Performance of Frog, faster than wind speed, Bruce numbers above 2 and can outsail almost everything in 2 to 15 knots of wind. No statements about stronger winds beyond “I tested the structure to ensure it was OK”.

The jpegs give the idea.

 

A story about politics good intentions and politicians need to look good. Politicians created the need for a good boat and after it became a political embarrassment, literally use a chainsaw to get rid of the boat. The Mayor/council of Montpellier City in 1983/4 decided a great way to promote the Region was to have an ocean racing boat. They wanted something that would stand out and decided on a radical proa. A proa with a near full wing sail rig. Good so far. Problems then began with a mast rig failure, discovery of some financial issues that impacted on the next election of the city’s mayor. The new Mayor/council then quietly ordered the proa be hidden from site and finally cut up by chainsaw in 1988 to “bury” the political problem.

The proa was “Montpellier Languedoc Roussillon”. The designer was Guy DeLage who designed, for its time, a very radically rigged Pacific proa. The 69 x 49.2 foot proa weighed 12,320 lbs all up and carried a 75 x 3.3 foot Kevlar covered mast with a “wing” cloth mainsail behind. With the jib on the balstron boom the total sail area was up to 2,050 square foot and the optional spinnaker could increase the sail area. There was a raisable T foil rudder at either end of the main hull that helped reduce pitching. As I said the rig was radical for its time, as C class cats were using multipart wing masts but ocean racing multis were only “exploring” the idea. The wing rig was studied in the aeronautical school of Toulouse (ENSICA) and validated in wind tunnel (CEAT). Also, the Pacific proa had an automatic ballasting system using dynamic water pressure. Way ahead of its time.

The proa was a pure racer and had minimal accommodation.

The construction was sandwich construction: Vinylester - Airex or methacrylate foam (Roycell) with glass either side. The rigging is made of carbon - epoxy - honeycomb sandwich with Kevlar on the skin of the solid wing (should have been sail cloth). The 69 foot main hull weighed 2,130 lbs, the 53 foot float weighed 1,150 lbs and the 2 connecting arms weighed 1,010 lbs each. A very light shell for a 69 foot proa.

So how did it perform. Very to extremely well. In light airs it often sailed at up to 2.2 times wind speed in flat water, EG in a 5 knot wind speed it could reach 8 to 10 knots boat speed in early trials and went faster after rig tuning. In open ocean it could be very fast topping 30 knots. This is the reason I said the spinnaker was optional. The only defect was the rig fell over at one point due to poor build of a connection between mast and the “rig support pole” which acted as a tension item unless the rig was caught aback where it was supposed to be a compression item.

After the rig failure there were questions being raised about why so much money was being spent etc and politics came to the fore.

The jpegs give the idea of a very fast radical proa that could have been developed a long way. Pity it was cut up due to politics.

 

The following came from the following thread. The original North American Catamaran Racing Association https://forums.sailinganarchy.com/threads/the-original-north-american-catamaran-racing-association.236716/page-3#post-7996912

I have done an item on this build before but here is the original article for your study. It gives a lot of understanding of a high performance cat design and possible build.

 

Guy Delage first ocean racing proa design was “Funambule”. Delage designed and built the proa launching the boat in about 1980. As this was an early pacific proa design it achieved many first but also had several issues. It could sail fast, for 5 years it held an outright speed record of 27.5 knots over a measured course and on a Transatlantic run averaged 11.5 knots (just over 10 days for the crossing).

Funambule (also known as Sdinox, Metabo, Lestra Sport) is 55.6 x 26.9 foot (was lengthened to 50 foot in 1990) with a weight of 8,800 lbs (some reports 10,000 lbs). The original schooner rig had 55 foot aluminium masts with 1,400 square foot upwind. Later the masts were 62 foot long with 1,500 square foot upwind and a 2,260 square foot spinnaker down wind. The draft varies from 3 foot to 6 foot over the variable draft rudder boards at each end of the main hull.

Now we get to the overall design. The main hull was given a lot of hull rocker and a low prismatic coefficient (PC) maybe 0.55 (means a fat mid body with finer ends). The latest proa designs have very little rocker rocker and high PC’s of 0.7 (much full ends, less midbody depth). Higher PC hulls have higher top speed potential with less pitching. Next was the relatively small initially mainsail only schooner rig. Funambule was very good reaching but was not as good upwind. The spinnaker help speed then jibs were added to improve performance upwind. Overall, the pacific proa had a lot of stability for its weight and could carry it rig in stronger winds which allowed the high reaching speeds.

The construction was early foam glass. It was a sandwich of e-glass polyester Airex foam. The hull mould is a timber frame where foam was screwed on then hand glass laid over the exterior then the interior. Slow, a lot of painful fairing but can produce a reasonable result. Denny’s intelligent Infusion is a lot faster and simpler.

The accommodation was basic racing, in short a few bunks, a small galley and not much else.

In 1981 it raced very well with Tour of Guadeloupe: 1st, Multihull Trophy: 1st, New-York / Brest: 1st in class and 2nd in scratch, Brest Speed Week: World Open Speed Champion (the record will last 5 years!). Also it was the smallest boat to have broken the record of the schooner Atlantic (14m at the waterline) in a little more than 10 days! In 1982 it did La Rochelle / New Orleans: 1st in 2 category and 3rd in scratch. There was many other racing efforts up until about 2012 when it was lost at anchor after a race.

The jpegs give the idea of a very good early proa design.

 

Atlantic proa.

 

Thanks for that one, Oldmulti. That was a very successful boat and one of the most traveled proas.
I grabbed a couple of the photos. It looks like it was nicely built.