Intenational Series - Vacuum Bagging vs. Wood Stringers

[RWS]

I've learned quite a bit about recreational boating, seamanship, handling, engineering, construction and design of fiberglass pleasureboats since my first 19' Force powered outboard.

Trojan revolutionized the industry when they introduced thier International Series in the ealy 1980's. The design was very successful and many of the new and unique features were quickly copied by others in the industry.

In a recent post regarding the 10 meter, another forum member mentioned that the earlier 10 meter Internationals were constructed with a full vacuum bagged liner system.

The later mid cabin models with thier higher cockpit floor featured wooden stringers encapsulated in fiberglass.

Is it true then that the 10 meter Internationals built with the full liner system have little or no wood in the stringers?

Is this true of all of the International series?

With a solid glass, uncored hull in the 10 meter (11 meters and up feature balsa coring) is the only wood on this boat the balsa coring in the upper deck?

Why would the company abandon the full liner vacuuum bagged system in the later years when they introduced the mid-cabin series of 10 meters?

I would think that the cost (if lower) would be outweighed by the VALUE of the feature.

If this is true, why didn't the company capitalize on the lack of below waterline wood in thier advertising?

I would love to learn more about this subject. What do you know?

RWS

[my10meter]

When I started looking at 10mtrs--I was aware that many people with mid cabin boats that had rotten stringers . Construction was glass laid over wood-- One boat ended up needing the stringers opened up --wet wood removed- dried out and wood replaced with new and reglassed. Everyone that had Tiara's warned me about the stringers-- The 10 mtr express came with a molded in liner with box beam solid glass stringers- I found this on a 1982 boat and it is the same on my '85. This liner made it possible to integrate the water tank and holding tank into the liner. A few changes happened from what I can tell on 10 mtr express boats with regards to the liner/stringer- and I will post pics when I return home(just arrived in St Pete today for 2 weeks) Earlier 10 mtr express boats had a hinged cutout that opened to get access to the shaft logs since the shafts go right thru the box beam stringer. Also the rear bulkhead wall was attached to the stringers with aluminum angle in the early boats- in my 85- it is glassed to the stringer. This setup is a good setup - no wood to rot- however expensive to laminate- It requires making a mold for one big part- the liner- making the part and it must be vacuum bagged to to inside of the hull to give it strength and avoid voids. ( this is vs laying in wood on end and laminating it to the bottom of the hull in the mid cabin setup. Vacuum bagging is labor intensive- and is probably one reason this was not done in mid cabins- Also- the motors are mounted up higher in a mid cabin requiring a taller stringer- thus- more cost with a liner type construction(just a guess- if the engine bed had to be higher- it might need more glass- more cost---you get the idea-) Trojan was building a quality product with this boat- but I believe they also cut some corners-- this was one they cut.
My questions are- can this setup handle the long term effects of diesel torque?
My liner had minimal moisture content when it was surveyed for purchase earlier this past fall.
Dana

[RWS]

I am attaching an article by Peter Bohr which appeared in the February 1987 issue of Sea Magazine.

I have highlightet the section related to the vacuum bagged hull construction.


Trojan International 10 Meter
A gutsy, avant-garde original

Peter Bohr

If you’re 47 years old, drive a Mercedes or a Corvette, operate your own business, have a net worth greater than $1 million, and enjoy power boats, then it’s not a bad bet that you also own a Trojan International series boat, probably a 10 Meter.

That’s the profile of the typical Trojan owner these days, according to a marketing survey just completed by the company.

Any boat builder – or automobile manufacturer or pasta machine maker, for that matter – would love to have customer demographics like that. And Trojan can thank its 33-foot International 10 Meter model for attracting such an upscale group.

It seems like only yesterday that Trojan surprised the American power boat industry with its avant-garde 10 Meter. But the boat is now in its seventh year and Trojan has sold nearly 600 of them.

The 10 Meter was a gutsy move for a staid builder like Trojan. For some 35 years the folks at Trojan’s plant in Lancaster, PA had been quietly turning out nice, conservative family cruisers. “Boats built to a price,” is how several marine surveyors described older Trojans to me.

The early Trojans were of course constructed of wood. When the company switched to fiberglass in the late 1960s, the status of Trojan boats moved upward a notch. But despite the change of materials, the designs remained much the same, hardly distinguishable from Chris-Crafts, Owens or boats from a dozen other American builders.

Then around 1980, Trojan president Don Seith took a flier. Armed with the progressive ideas of naval architect Harry Schoell, he convinced Trojan’s parent company, Whittaker Corporation, that Trojan should build a trend setting, new kind of cruiser. Inspired by the ultra costly, ultra chic boats from Italian builder Riva, Schoell developed his own rendition of Riva’s “Med-style” boat.

The 10 Meter’s lines, inside and out, are excitingly different from most cruisers, as different as a Chevrolet Corvette from a Ford Country Squire. With its long, sleek, downward sloping foredeck, the boat resembles some wild beast ready to pounce on its prey. Below deck, the 10 Meter is filled with modernistic curved bulkheads that not only make the interior seem more like the cabin of a Lear Jet than a yacht, but are also very space efficient.

“The boat’s visual appeal initially catches the interest of buyers,” says George Rinderspacher of Pacific West Yachts in Newport Beach. “However, it’s the boat’s performance that finally grabs them.” George ought to know; he sold 24 new Trojans in 1986.

Indeed the 10 Meter’s success is based on more than sexy styling. Harry Schoell came up with an innovative hull to go with the 10 Meter’s innovative lines topside. The hull, called the “DeltaConic” design by Trojan, has unusual 18-inch wide, horizontal chines that run from bow to stern on either side. In between the chines is a more usual modified V-hull, one that’s quite deep at the bow but flattens out toward the stern.

What makes the 10 Meter truly different from other boats is its almost uncanny stability. The 10 Meter’s wide beam combined with the wide chines quickly stills any rolling motion. I’ve never been aboard a similar sized boat that felt as stable at dockside as this Trojan. Under way, the chines make the boats feel – to use an old car salesman’s cliché – like it corners on rails. Mind you, steering response isn’t especially quick. But the boat’s attitude is solid and secure as those chines lock in for the turn.

The 10 Meter’s standard twin 350 Crusader engines use a combined total of 18 gallons of gasoline per hour at a cruise speed of 28 to 30 miles per hour, according to George Rinderspacher. An AquaSonic muffler system that vents exhaust out the sides of the hull beneath the waterline is integrated into the hull during its layup. The system make the 10 Meter an unusually quiet power boat whether idling in the slip or running full bore.

The 10 Meter’s hull is solid fiberglass, but the decks and cabin side are cored with end grain balsa. My marine surveyor/advisors all commented that Trojan’s gelcoat work on the 10 Meter appeared to be of high quality.

Trojan also uses some innovative construction methods on the boat. For instance, the company vacuum bonds certain parts of the boat together. Liners are literally sucked against the hull by a vacuum pump until a resin and glass paste hardens. The technique gives a very uniform tight fit.

The 10 Meter comes in three versions. The Express, which made its debut at the Miami Boat Show in February 1981, came first. Like all the versions of the 10 Meter, the Express has a forward stateroom down below as well as a large galley, a dinette and a head. The helm and cockpit on the Express are essentially a single area, providing a huge arena for playing, partying or sun worshipping. And that’s exactly how most owners use their 10 Meters, according to the company’s survey.

The slightly more conventional-looking Sedan has a streamlined flying bridge, a saloon with a convertible sofa, and a severely abbreviated cockpit. A good configuration for cooler climes, the Sedan was introduced in early 1982.

The Mid-Cabin went into production in 1985. The exterior profile of this version is virtually identical to the Express. But the Mid-Cabin has a small sleeping area for two (with sitting headroom only) tucked under the helm.

Last year Trojan introduced a stretched version of the 10 Meter, called the 10.8 Meter (35 feet). It’s a 10 Meter Sedan with an extended cockpit and is aimed at the sportfishermen.

There have been no major changes in the basic 10 Meter design since its introduction in 1981. However, in one fell swoop in 1983, Trojan made some 200 detail changes. These included such things as upgraded interior fabrics, new instrumentation for the helm, and heavier stainless steel port lights. At the same time, Trojan abandoned what surely must have been one of the all-time worst gimmicks aboard a small yacht: electrically operated doors to the forward stateroom and head compartment. They were indeed attention getters at boat shows, but a marine environment is not exactly ideal for electric motors.

Don Seith’s gamble has obviously paid off handsomely for Trojan. The company still builds conventional cruisers (the “Classic” series), but their percentage of total sales has dwindled to 20 percent. Meanwhile, Harry Schoell’s 10 Meter has spawned a whole series of International boats, ranging from the 8.6 Meter (29 feet) to the 13 Meter (43 feet). Moreover, other American power boat manufacturers have fallen all over themselves to come up with Med-style boats of their own.

To be sure, a Trojan International 10 meter is not for everyone. But then neither is a Corvette.

This article first appeared in the February 1987 issue of Sea Magazine.

[RWS]

My 1983 express cruiser has the full liner.

It runs from the transom all the way to the forward bulkhead.

There are 4 stringers moulded into the liner.

The liner is fully finished and gel-coated and makes for a really nice, smooth, easy to keep clean engine room and lazarette floor that is the same white color as the deck.

A 40 gallon wastetank is built into the ceter of the v section of the hull. I've had the lid off of this to reseal it during the refit and found the inside to be constructed with fully finished, gelcoated fiberglass with a built in baffle made into the lid which also adds rigidity. This 40 gallon tank runs betwee the center stringers from the drop down area of the engine room bilge al the way to the forward bulkhead.

Moving forward on the salon side of the engine room bulkhead, there is a drop down area to the hull with no visible liner for the forward bilge pump. Forward of that area is an under floor locker, the bottom of which is the lid of the built in 40 gallon fresh water tank also between the stringers.

I don't really know if the vacuum bagged liner exists forward of the front engine room bulkhead.

The cockpit deck is balsa cored.
The rear engine room bulkhead is marine grade plywood as are two outboard vertical support pieces adjacent to that bulkhead and below the stainless steel engine air intake grilles.

Additionally, the non structural, removable panels in the center of the cockpit, behind the coaming and below the rectangular air intakes are made of plywood. The first owner of my boat added outriggers to the deck area above these and years of water draining through the center outriggger opening directly onto these panels caused rot which had to be repaired.

All the removable hatch covers are painted marine grade plywood.

The 454 engines featured factory Crusader adjustable engine mounts each riding on a block of OAK that was fastened to the top of he stringer with simple lag bolts.

I believe but cannot confirm that the hollow stringers may have a wood strip embedded in the top of the stringers, at least in the engine room area for hose lag bolts to find a grip.

Aside of the wood mentioned above and with the stringers being virtually wood free, Is anyone else aware of any other wood in this vessel?

Other than the rear engine room bulkhead and the backing for the engine room lag bolts is it safe to say then that there is no below the water line wood involved in the construction of this vesssel?

If you read this far, sorry about the lengthy post, however it is fascanating to me how this boat was designed, engineered and built but the advertising didn't really cover all these insightful and ahead of it's time construction details.

Athough the 10 meter was a good seller, perhaps management decided tha the higher construction costs for the vacuum bagged liner didn't translate into better sales. That may be the reason for the mid cabin model being constructed with fiberglass encapsulated wood stringers.

Based on resales, it seems that after the mid cabin model was introduced, there were fewer express cruisers built. It's rare to see one available for sale built after the 1986 model year.

Perhaps the mid cabin models provided a higher profit margin?

Maybe they better competed with other brands who had by the mid to late 1980's already adopted the new styling features from the Trojn Internationals?

Comments?

RWS

[ltbrett]

There is some wood in the bilge pocket between the fresh water tank and the engine room bulkhead. It is on the port side, probably not structural, but my surveyor dinged it for rot. I think the electrical wiring is mounted on a piece of wood behind the breaker box. And my boat also has a strip of wood inside the leading edge of the radar arch. Some of the coaming pads are backed by wood, while others are glassed. This is a potential area for rot, although it is clearly not structural. Overall, not much wood onboard.

Brett

[davescarrs]

I redid my coaming pads across the transom of my 1987 10 Meter Trojan Express. The upholstery padding had become waterlogged, frozen, thawed, etc. and the staples began to fail. The wood had sat waterlogged for at least two years (boat was abandoned). I have to tell you, once I took off the naugahyde and the upholstery foam and let the wood dry, it was absolutley fine. The corners were angled with the help of a strip of glass matte, but the rest of the wood was bare. I don't know if the wood is simply marine grade or what, but the boat in it's entirety seems to be very well made with terrifc quality products (except for the metal staples).

I simply cleaned and let everything dry out and put everything back as found and used stainless staples to reaffix.

[RWS]

Trojan was owned by Whittaker when the Intenational series was introduced.

This new line revitalized the company and all sales skyrocketed.

Sometime in the late 80's the name Whittaker disapeared and the moniker Trojan-Bertram was used until the company succumed to the recession and Luxury Tax of 1992 + -.

Any comments on the design changes and eventual elimination of the nearly wood free vacuum bagged structural design in the 10 Meter?

I would think that replacing that wooden lazarette bulkhead with a fiberglass unit would have allowed the company to advertise 100% wood free (below the water line) construction.

Other companies have successfully capitalized on this concept, however in all the literature I have collected on the 10 meter, I have not seen a single mention of this feature.

The design and engineering was clearly well ahead of it's time.

Anyone know any more fcts on this?

RWS