Victoria #2 - A Competition Optimized Victoria One-Design Class Model
by Rod Carr
When the Thunder Tiger VICTORIA model appeared, I was asked to provide a kit review for RADIO CONTROL BOAT MODELER magazine. The review met with much interest and a second article was produced which focused on optimizing the boat for R/C round the buoys racing. Subsequently, the boat obtained sanction from the American Model Yachting Association as a one-design class. I was asked by the provisional Class Secretary, Chris Cafiero to serve on the new Class Technical Committee and assisted with the drafting of the Class Specification. Now, the challenge was to configure a new boat, which explored the edges of the Class Rule envelope as an assistance to the Class in the finalizing of its rules. Final evaluation of the development effort was be based on boat for boat performance testing in the newly formed Seattle Model Yacht Club VICTORIA fleet.
The design objectives were:
I would like to acknowledge the assistance of the other members of the VICTORIA CLASS Technical Committee, Joe Frasier, Tom Foster and John Forester whose continuing debates on the configuration to be allowed and the open sharing of practical, on the water experience with the boat were valuable to the decisions made in building #2. The encouragement of the original Class Secretary, Chris Cafiero is also gratefully acknowledged. His active support for such projects is one of the reasons why the VICTORIA Class has such a bright future.
The VICTORIA Class Rule maintains strict requirements for the use of a stock hull/deck, rudder, in keel and bulb. Above the deck, the profile of the sail plan is controlled within reasonable tolerances which allow for experimentation in sail making by the skipper or for substitution of after market sails from recognized model yacht sailmaking firms. Deck fittings, standing rigging and running rigging are unrestricted as to form and function, with two channel radio required for rudder and sail trim. This approach provides for experimentation while controlling those areas which have direct contributions to boat speed. During construction of VICTORIA #2, weights of components were taken with an Acculab #1200 scale to a precision of 0.1 gram. A ready-to-sail target displacement of 4.5 pounds (2,041.5 grams) was established. Table 1 provides two columns of weight data. The first column is for a kit boat with Futaba R/C gear and the S-125 sail servo. It was calculated to be approximately 9.2% over the target displacement if built as indicated. The second column is for VICTORIA #2 and includes additional components substituted for the kit pieces. Additional weight savings could be accomplished by using a micro receiver such as the two channel unit available from Clancy Aviation and by selecting a smaller battery pack. This would allow sailing at the absolute minimum displacement allowed.
Under deck reinforcements of 1/8" aircraft plywood were attached with 3M 5200 Marine Adhesive. These included back-up for jib rack, jib sheet exit guide, chainplates, and mainsheet exit guide. A tapered and beveled block of white pine was fitted to the centerline of the hull at the transom to bond hull and deck together and provide a strongpoint for attachment of the backstay tang and manual sheet adjustment points. Please refer to Figure 1: Underdeck Back-up Blocks
To prevent flexing in the keel trunk area, two collars of 1/16" and 3/32" aircraft plywood were bedded in 3M 5200 Marine adhesive around the keel trunk. The intent was to prevent flexing and fatiguing of the hull at the base of the trunk that had been reported by several skippers sailing the similarly constructed CR 914. Please refer to Figure 2: Keel Trunk Reinforcement
Under the guidance of the Class Secretary, #2 was authorized to establish the applicability of carbon fiber spars and the use of standing rigging approaches typical of established racing one design boats like the East Coast 12 meter. This approach has been used as a means of component evaluation upon which rule changes may be made to carefully modernize a one-design while not obsoleting existing boats outright. A single piece carbon fiber tube (Pro-Spar PS-19-352, $6.37 per 54" length) was shortened for a mast, and somewhat smaller diameter carbon tubes were selected as main boom and jib club (see Table 1). It is the author’s opinion that the class rule could be amended to remove the restriction on spar materials, insofar as carbon fiber is no longer an exotic material either by chemistry or price. Please refer to Figure 3: Standing Rigging (Schematic)
Jenny struts of 1/16" music wire (2") were fitted at the jib stay
intersection on the mast (33.5" above deck). Jenny stays provide the ability
to maintain a straight upper mast shape under the loading of higher backstay
tensions. The upper shrouds exit the mast at the jenny struts and proceed
downward through the spreaders. They terminate in modified A.J. Fisher
turnbuckles that have had the bales replaced with nickel-silver hooks which
engage the chainplates.
A single spreader was fitted (17" above deck) using a roughened 2" x 1/16" music wire stub epoxied through the mast. Brass tube extensions were flattened and drilled at the outboard ends to give an overall spreader length of 6". Lower shrouds exit the mast just below the spreader stub and terminate at the chainplates as described above.
The aluminum gooseneck mount was filed from 3/16" aluminum stock and fitted in a slot cut in the after centerline of the mast. Dubro #2139 - "2-56 Swivel Ball Links for 4-40 Rods (w/hardware)" are used to provide the swinging action. (See Figure 4). The vang uses a length of 2-56 threaded pushrod, and an A.J. Fisher #530 (3/4" take-up) turnbuckle modified at the base. Please refer to Figure 4: Gooseneck/Vang
Adjustable attachment points for outhauls, downhauls on the jib club and main boom were made from 16 gauge nickel-silver wire, using the methods developed and described by Larry Robinson and Bob Wells in their reference "The Manual for the East Coast 12 Meter" available from Ragged Symmetry, 5425 Parkwood Lane, Mercer Island, WA 98040.
An extended backstay crane was mounted in the mast top, by plugging the mast with a wooden dowel, and then cutting a slit with a razor saw to accept the 0.020" stainless steel crane.
The backstay consists of a length of 30 pound Steelon plastic covered stranded leader wire, with a 30 pound braided dacron bowsie adjusted loop at the bottom. The backstay hooks into an A.J. Fisher brass tang mounted on the transom (Ed. Note - Tang bends up, but doesn't protrude back beyond stern). Under the top mounting screw of the tang, a small v-shaped piece of brass carries two grommets through which pass the adjusting loops for the jib and main sheets. (See Figure 5: Running Rigging.) An external adjustment of the closehauled sheet position is necessary to allow for quick response to changing wind conditions between racing heats without calling for time out.
Since #2 was destined to be actively raced, every effort was made to provide for smooth and trouble free movement of the main and jib sheets along the deck. The scale detail kit pieces were not mounted on the deck for this reason. The jib rack was made from the same brass section as the chainplates, and is also 2.5" long.
A mast step was fabricated out of 1/8" aluminum and was drilled out to accept the keel retaining bolt. The keel retaining nut was reduced in height to clear the bottom of the vang. A series of holes was drilled along the mast step centerline at ¼" intervals to allow for movement of the rig to obtain boat balance. (If the mast step was tapped 10-32, it could be threaded onto the keel bolt, but the existing hatch coaming would interfere with removal if the keel was later to be removed.)
Brass through deck fairleads were fitted for the jib sheet (10.5" aft of bow), and the mainsheet (20 ¾" aft of bow) by drilling through deck and backup blocks. The sail control unit was mounted as near to the centerline as possible immediately after the battery pack which is just aft of the keel bolt tube. A double ended arm allowed the following rigging paths: Main sheet - Mainsheet fishing clip attachment point on boom (7 3/8" from gooseneck center point) through deck sheet exit guide forward on starboard side to block on winch arm, then aft through cockpit bulkhead to terminate in a bowsied loop in the cockpit. Jib sheet runs from the fishing clip attachment point on the jib club (7 ½" aft of the jib club swivel), down through the deck sheet exit guide to the turning block on the sail control unit arm, forward to a turning block mounted forward in the hull, and then all the way aft to a small hole in the forward face of the cockpit to a bowsied loop in the cockpit. Make sure that the hull mounted turning block is as far ahead of the sail control unit as possible, consistent with being able to reach it with some long tweezers to rig replacement sheets. Please refer to Figure 5: Running Rigging
Also, a new hatch cover of 0.015 white styrene was made, which allows a significant weight saving. Mylar "Carr" sails were fitted, with the mainsail mounted on a jackwire led through a series of small cotter pins pushed through the mast. This provides for a good sail to mast seal, and still allows excellent ability for the mainsail to swivel as the boat changes tacks. Tell tales were fitted to the mainsail leach at the after end of the upper batten as directed in the Trim and Tuning Manual that is provided with the sails.
Early testing of the boat as described has shown her to perform well, with substantially improved boat speed over stock kit boats. Boats with replacement sails are essentially the same speed, but testing with skipper swapping has yet to be accomplished and will require a major commitment of time.
In conclusion, the boat as constructed is much stronger and robust than the original kit. It is very close to the minimum allowable displacement, thereby providing maximum acceleration out of the tacks which is critical in a boat of this size. The use of carbon fiber mast and booms does not confer an easily observable differential in performance, nor did it require any skills or tools beyond what is typically used in model yachting construction in general.
Remember to provide a "sling" between the uprights of your boat stand to support the weight of the keel. This will prevent hull distortion during long periods of storage.
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