build it and they will come?
So Cal anarchist dave Beck takes a new look at what is now thought of as not only old, but nearly forgotten, the Schock 40.
Anyone who has sailed on or against the Schock 40 can’t help but think that there is a huge amount of unrealized potential in the basic design. This takes nothing away from the achievement of W.D. Schock Corporation, and Tommy Schock in particular, for putting such a radical design into production. Given the often stunning performance demonstrated by a basic design that is now at least 12 years old, built for production using carefully executed, but standard polyester/glass production techniques, there is a huge leap to be made by moving to current practice in structure, materials and rig design. This proposal is based on a number of informal studies over the years, up to and including a serious look at revamping Ed Feo’s Mad Dog before he donated and sold it.
Assumption 1. That one has access and use of the Schock 40 molds from Tommy Schock. He has indicated a willingness to loan/lease the molds for the right project. In addition, a license fee will need to be paid to Dyna Yacht, the owners of the design. Why not a new design? The Schock 40 hull, deck and interior are sophisticated, well thought out, functional and practical designs for a high performance sport boat of this size. The tooling exists and is easily adaptable to the concepts proposed below. While the input of a naval architect should be sought for the engineering of the upgrades and hardware, a huge amount of design work and custom tooling can be skipped using the existing tooling.
Assumption 2. The new boat would be constructed of vacuum/oven cured carbon-epoxy, using an appropriate mixture of honeycomb and/or high performance foam cores.
Assumption 3. Beyond updating the canting ballast system for the higher loads, the boat will be kept as simple as possible. The basic Schock 40 deck layout is excellent for a practical, 40 foot sport boat, and that the basic canting ballast hydraulics and mechanism were robust and well designed. With that;
HULL/STRUCTURE: Matt Brown, one of the designers of the boat has calculated that with a bagged, cored epoxy/carbon structure, 1000 lbs of structural weight (7000 lbs total displacement) could be conservatively taken out of the Schock 40, compared to the stock polyester/foam/wet layup structure. Depending on how sophisticated the laminate design and build practices, it is likely that even more weight could taken from the structure. Logically, this would be put back into the ballast bulb. This translates, if combined with a proposed total draft of nine feet versus the stock eight feet, to effectively doubling the available righting moment.
- The pacing item nowadays is the billet of stainless or structural steel that would be machined into the ballast strut. It’s the first thing ordered on all modern boats and usually one of the last items delivered. While welded ballast struts can be fabricated, the history is not good unless U.S. Naval standards of fabrication, materials and inspection are applied. The solid, machined strut is a high performance, well defined approach, unless you are going to fabricate the strut from monolithic carbon, which introduces a whole new world of design and fabrication issues. The strut should have a root pivot that is a larger fraction of the chord than the stock boat, with more robust structure in the boat, but using the same basic bearing and configuration design as the stock boat.
- The boat should be reconfigured with a modern, deep tiller-rudder placed at the present design’s tiller position, aft of the aft CTBF rudder location on the stock boat.
- The ballast strut should be made a foot deeper in addition to the 800-1200 lbs of additional ballast in the bulb. The strut and hydraulics mechanism would have to be beefed up accordingly. In addition, the strut must have an integral kelp cutter.
- The forward foil should be replaced with a single, centerline, flapped daggerboard just ahead of the standard mast position. From a balance standpoint, this will have to be swept some amount, determined by a detailed sail plan/foil balance analysis. Twin, asymmetric daggerboards are ideal hydrodynamically. However, for a boat that is raced inshore, with lots of tacking and jibing, these advantages fade. Further, even the beamiest Open 60 and Volvo boats are moving these boards toward the centerline, and making them more vertical, further reducing the advantage over a single flapped foil. In addition, the Schock 40 hull is narrow enough that the bilge board advantage is further reduced. Finally, the single board is simpler and much less expensive than the twin boards. The trunk would require the enclose head door to be positioned on the forward face of the head compartment, as shown on the accompanying drawings.
- The original Schock 40 was designed without a structural bulked between the shrouds and the mast. Given the higher loads anticipated for the upgraded design, this should be rectified. Modern race boats have ring frames, support bulkheads and/or struts/tie rods in this area.
DECK: The only proposed change to the deck is to extend the deck molding aft, making the deck beam constant from the hull’s maximum beam point aft to the transom. This amounts to an extension of one foot at the transom corner. The benefit is to increase sitting out and/or sail stacking leverage on this narrow hull. This can be done easily on this design as the deck sits atop a turned in flange on the hull molding. A gradual increase in deck extension core thickness aft from the maximum beam point and lateral reinforcement with the carbon/epoxy skins should make this a simple, lightweight addition to the boat that will also have the advantage of significantly increasing the sheeting base for the ayso spinnakers, jib top and code zero sails.
RIG: A modern intermediate modulus carbon rig should be designed and purchased from Hall, Southern spars or other spar manufacturer. The boat is set up for swept spreaders. Run the uppers (C-6 rigging, of course) over two or three sets of curved “scimitar” spreaders to the masthead. Move the jib tack forward to the stemhead and size a fractional rig to take advantage of the new stability. The Schock 40 has just under 800 sf of sail in the stock sailplan. Most 40 footers nowadays have 900 to 1000 square feet, plus. Some analysis would have to be done here to come up with an optimum. The rig dimensions shown in the accompanying drawing provide an upwind sailplan of 900 sf, and give an upwind sail area/weight ratio of 40 with a non-overlapping jib. This is equivalent to the high powered J-125 with a genoa. Keep in mind that the Schock 40 C is a 7000 pound boat, versus 9000 pounds for the J-125 and 15,000 pounds for a King 40. Adding a masthead, upwind code zero to the sail wardrobe would jump this further if desired. The rig is runnerless per modern IRC driven practice. The trend is toward a square topped main and split upper backstays. The design shown compromises toward a small square top and single, whip deflected backstay. You could keep the retracting bow pole, but the simplicity, dryness, and light weight of a fixed bowsprit between five and six feet long is very attractive.
ENGINE INSTALLATION: The retractable, 15 horsepower Honda outboard installation could be retained. This is the lightest, and is still relatively inexpensive. Consideration should be given, however, to a small 12-15 horsepower diesel. This can be mounted forward of the retractable outboard box, providing a platform for the pit crewman and a step down into the cabin. The weight is higher (but with a more centralized location for the mass), while one gains an onboard alternator charger that’s invaluable if any distance racing is to be done. Prop installation can be conventional strut/shaft or saildrive. However, if an inboard engine is installed, consideration should be given to the type of fixed prop, retractable systems seen on many newer IRC boats. This is becoming established technology that can work reliably and efficiently. One attractive feature of the Schock 40 C is that this remains a boat and ballast package that is small and light enough that a battery powered canting ballast system, recharged at the dock, is more than adequate for a three-day regatta. The engine will not need to be run during racing to operate the ballast system. The diesel does give one an on-board charging option, however.
That’s the basic program. The result would be a highly refined, but simple and fun boat with jaw-dropping performance. Even today after the Volvo 70s, Cookson 50 and the big R-P CTBF boats, most sailors don’t realize the performance leap these boats represent. Further outside of the Farr 11 37 footer, no one has developed a boat this size that fully exploits the canting ballast boat’s potential. Someone should build this boat…Should they? Post your comment in our Sportboat Anarchy Forum, brought to you by Viper.