More from SpeedDream
After unveiling the SpeedDream concept a couple of months ago, New England-based designer Vlad Murnikov is continuing to shed light on his planned record-breaking monohull as the project moves forward.
According to Murnikov, who designed Fazisi, the Russian entry in the 1989-90 Whitbread Round the World Race, SpeedDream will be capable of sustained speeds of 40-45 knots and runs of 1,000 miles in a single day. He says the boat will be capable of shattering a number of records currently held by multihulls.
The following are a few excerpts from the team’s latest press release:
Monohulls vs. multihulls:
"For decades catamarans and trimarans have proven themselves to be the fastest boats under sail," says Murnikov. "All this time these multihulls have enjoyed unrestricted development leaving their designers free to explore every possible recipe for speed. Monohull development, on the other hand, has always been governed by strict class rules which puts a big damper on single-hull performance capabilities."
Today’s fastest monohull, the VOR 70 (a class created for the Volvo Round the World Race), is a relatively conservative design developed in accordance with a stringent "box" rule in order to keep all boats similar and to reduce costs and risks, associated with the ultimate ocean race. These rules put limits on length, beam, draft, displacement, rig dimensions and sail area, all the major design parameters, as well as materials that can be used for boat’s construction. And yet, despite all these restrictions, VOR 70s are capable of reaching speeds in excess of 40 knots, the same as some of the fastest multihulls. The problem is, much wider and shorter monohulls tend to slow down after each burst of speed, while catamarans and trimarans, with their needle-like hull forms, can sustain higher speeds for a substantially longer periods of time. This explains why multihulls dominate the record pages.
The SpeedDream team believes, however, that the current superior multihull performance could be matched and even exceeded by a monohull if we are able to throw away all restrictions and design the most advanced boat possible.
“After all, multihulls, no matter how long and slender, still sail in displacement mode while high-speed monohulls can glide over the water in a much more efficient planing mode,” explains Murnikov. “We see potential for a quantum leap forward in monohull performance, a true design revolution. While this is happening catamarans and trimarans would continue their incremental advancement becoming larger and wider while growing more complex and costly.”
Generally, light boats are fast. Monohull critics are quick to point out that the ballast weight that a traditional single-hull boat has to carry in order to achieve sufficient stability is dead weight most of the time. Recent advancements in canting keel design allow for enormous gains in stability while reducing ballast weight. In fact you can hardly call a canting keel a “keel.” It’s more accurately a “stability strut” that adds power in a very efficient and effective manner. It’s true that multihulls don’t need ballast for generating righting moment but they do have to carry around the weight of at least one or even two extra hulls, plus all the complex structure necessary to keep it all together.
High performance results from a combination of two main factors: providing a boat with enough power and reducing resistance in order to utilize this power in the most efficient way possible. Most designers focus performance optimization on increasing power. Multihulls are typical of this approach as they grow larger and wider with each new generation in order to achieve higher and higher sail-carrying capability. This, however, results in over-powered vessels that are inevitably over-stressed requiring a more and more robust structure to survive. This all comes at the expense of extra weight which in turn calls for even more power to maintain speed.
“Our solution is to reduce drag, by all means possible,” says Vlad Murnikov. “This way all the available wind power is used more efficiently requiring less sail area to achieve higher speeds. Less righting moment is needed, the boat is less stressed and will be lighter while remaining strong. Lighter means faster.”
To greatly reduce resistance, the SpeedDream boat features a relatively narrow, slender hull, almost triangular in plan view and equipped with a sharp wave-piercing bow. The goal is to reduce drag in heavy seas as well as minimize pitching and slamming.
The boat is designed to sail most of time at a constant heel angle of around 20-25 degrees. This angle of heel will be maintained by adjusting sail area and keel angle in accordance to the changes in wind strength. Both the hull and rig are optimized to be most efficient in such conditions with the hull having two narrow planing surfaces port and starboard, each tilted at 20-25 degrees. Further design development will concentrate on verifying the optimal heel angle and determining both the shape and width of the planing surfaces in order to achieve the best combination of maximum hydrodynamic lift and minimal hull drag. The resulting hull design will have minimal volume and surface area with its buoyancy and hydraulic lift moved as far outboard as possible.
The Ultimate Canting Keel
VOR 70 rules limit keel cant to 40 degrees. The geometry of most modern canting systems allows for a maximum cant of up to 50 degrees. Beyond 50 degrees the loads grow dangerously high. For SpeedDream we have developed a proprietary system that allows much higher cant angles while at the same time being able to significantly reduce loads. The goal is to ultimately sail the boat with the keel completely out of water thereby removing a significant amount of drag. Even if the keel is going get submerged periodically, on the whole this concept promises sizable benefits to overall drag reduction.
Making a Wet Boat Less Wet – and More Beautiful
It’s hard to underestimate the importance of the deck design and layout as it relates to performance since at high speed the deck will frequently get submerged. Its shape will be sculptured to shed water as quickly and to throw as little water and spray forward as possible and to prevent large amounts of water reaching the cockpit. All of this will help reduce resistance and provide the best protection for the crew.
“Naturally the task of protecting the crew from the elements on a boat intended to reach 50+ knots in real ocean conditions is an enormous design challenge, but we have a few interesting tricks up our sleeve that will help make this inevitably wet boat a little bit less wet and more comfortable for her crew,” says Murnikov.
The deck, with several strategically placed breakwaters, is designed to shed water aside as quickly as possible. The cockpit is set far aft and is significantly elevated relative to the rest of boat, and both the helmsman and crew are protected by good-size dodgers. The cockpit sole is a mesh trampoline with a deep, steeply sloped channel below that allows water to easily pass aft and discharge through the open transom with minimal impact on the crew and boat speed.
“It has to be said that so far no offshore sailboat has ever sailed at such speeds so we are venturing into totally uncharted territory. No one quite knows what we will face there,” admits Murnikov. “High-performance sailing could be dangerous, but so is climbing Mount Everest or driving an F1 car. Our design team will keep working on making this boat as safe as possible and we believe that the experience gained throughout our project will greatly benefit all offshore sailors.”
All the functional attributes of the SpeedDream design also contribute to the boat’s strikingly futuristic image. “I view design as part science and part art and believe that beautiful boats are fast boats. This boat looks like nothing ever seen before and to my eye she is very beautiful, and therefore she has to be very fast,” jokes designer Murnikov.
For more on SpeedDream, click here.