Here the Greenheart Project shares the latest state of our designs, and solicits ideas from you.
The latest official designs can be found below. Use the menu on the left to see our design goals, earlier versions, original concept drawings, or to contribute an idea of your own. All pages may be commented on - and please do comment. The more comments, the better discussion, and the better ideas evolve. (click on any image to enlarge)
Specifications
LOA: 31.5 m / 103 ft Beam: 7.8m / 25.5 ft Displacement: 220 t Sail area: 300 m2 / 3230 ft2
Photovoltaic (PV) fixed array:125 m2 / 1313 ft2 Electric drive motors: 200kW DC x 2 Batteries: Lead/Acid traction
Cargo capacity: 3 TEU (20ft standard containers) -volume / 50 t -weight Hull speed: 10~11 kn
Here are the newest drawings from Kaku-san
Here is the new transom design with the reverse angle. The after edge of the cargo deck extends past the RoRo port to provide a boat landing. The RoRo port (tailgate?) can be used in the horizontal position, as a work platform (fishing, diving, dredging, pile driving, etc.) in protected waters and light seas because of another watertight port that separates the after hold from the main hold. It can also be lowered past the horizontal, as a landing ramp for beaches, a gangway for low docks, and a ramp for launching the ship's boats, and shipping fishnets, salvage, etc..
The two hatch covers and the two house tops will be covered with PV modules. Some of the rooftop panels on the pilot house will be partially transparent so the helmsman can see the mainsail. One idea [not pictured] to increase the PV surface, is to fit the side and after windows of the deck houses with PV-covered steel 'storm shutters', hinged at the upper edges so they can fold up and out to catch more sun (and rainwater).
This view also affords a good idea of the location of the mast/crane pivots (tabernacles?). We have been discussing moving these outboard to the rails.
(Play and pause this video to see the present design rotate)
New rig and sail plan
We went back to a single mast. We gained a lighter, easier-to-use rig, and lost the ability to load a laden container over the bows. We can, however, use the mast/crane to load over both the bow and stern, 3 or 4 tons at a time. The Version 3 rig, with the twenty+ ton derrick on the bow has been relegated to a possible future option for specific applications. With this gaff rig, we are also superseding the more complicated 'split main' rig. (See left menu > Previous versions).
The stability study above shows how the RORO port on the transom clears the waterline at various angles of heel.
A slightly revised sailplan below, shows an adjustment to the foot of the staysail to allow more visibility to the helm. There are also larger centerboards (keelboards?) drawn in for improved upwind performance. The transom view shows the boom outboard to determine the danger of rolling while running downwind.
We are also considering the roller furling/reefing mechanics for the mainsail.
Loading and Unloading
Principally, using the mast/crane over the bow and stern is pictured here. Not pictured is loading through the RORO port in the transom. The arc shown in the plan view shows how the boom fixed on the pilot house could service both the main and stern hatches as a derrick.
The shift of load depicted at the crane's central position, illustrates the technique of using both throat and peak halyards as hoists to control the transition through the vertical.
The red lines are cables in a back-up safety brake to prevent the mast from accidental falling. I imagine a triangular loop of cable with round turns on a drum that has a hand brake and centrifugal brake.
The blue lines show the load-bearing stays and mast/crane hoists. The transom view of the split backstay shows the lateral support for the 'lifting arm'/mainsail boom, even at low angles. (See Jan Heise's comment #5 in Left menu >> Open Contributions.)
The "Ducking" View (i.e. mast down for low clearance)
Note: This drawing shows the version 4 hull, not the current version 5.
The vertical clearance has been reduced since Version 3 by about a half meter. We have gained lots of 'bowsprit' though, when the mast/crane is on deck.
General accommodations
This drawing has not yet been updated to show the version 5 transom, pilot house, and sheer, although other details are accurate.
The hull, decks, and holds remain unchanged from Version 3. Not pictured is a watertight port between the wider aft hold, and the narrower main hold (just aft of the stairwells). This will allow us to open the stern hatch at sea (to launch and retrieve boats, to fish, etc.) without flooding danger.
We are also thinking of some changes to the pilot house layout. The bridge forward, with a movable light and sound partition, then the saloon (not exactly as pictured) with a large table/counter joining it to the galley which runs along the after bulkhead. The cook will have the view over the transom through opening windows, and be able to reach over the work counter forward to the mess table (no need to carry trays of food or drinks around - just hand them directly out of, and into the galley section
In my opinion now the boat has a too small centreboard.
Large Jib are also difficult to use.
Thanks for the comments. Yours is one of several critiques of the centreboards ( We are looking for a better name since they are off-centre ) Some ideas we are working on include a set of larger fan-shaped swing keels like the ones pictured, and a rectangular-profile asymmetrical foil.
We are now thinking that the main & staysail can be roller-furled on wire foils and stowed during cargo handling along the outboard side of the mast/crane. This will speed conversion from sail to cargo, and back to sail. It still leaves the sail-handling problem of the large jib. Radial slab reefing?
- Pat
Some comment from a sailmaker and captain on big sailing ships.
It should be well when you change your rig for a better performange. Points are:
1. The forestay of the jib is too flat, upright vertical sails has the best results.
2. When you make the " gaff"of the main somewhat longer, will be better, because;
a. The (after) leech is more vertical. Better for sailsperformance.
b. The surface is somewhat bigger. The ship can easely have some more surface.
3. I think the mast gives too much resistance and also give too much fals current to the main.
In general you can say how more vertical lufs and leeches, how better the sail performance, especially closehawled, the course, you sail the biggest part of time.
Personally I will never construct a centreboard, because:
1. In the history all the big freight ships has problems. You can learn from our grandfathers.
2. It is always risky and a weak point for damage.
3. It is expensive, take much place in the ship.
4 The axe and the box, you cannot do anything for maintenace.
5. When the centreboard with waves hid the ground, it warped, you can do nothing. you can't go to a slip. The only way is to remove the axe.
6. A better choice is a keel in the middle of the ship over the total lenght from about 30-40 cm. It sails comfortable. I had a ship of 50 meters and it was surprising how good she sailed closehauled. On all the courses she sailed very well and stabel on course. All the seaships from about 1900 and a tonnage from 200-600 tons have the same keel. This is a expirience from years and years. The little ones have also a v- bottom.
A solution will be to take two square sails with three yards. It sails on every course very quiet.
Also a expirience: you can have for bad weather a bigger number of sails than reefing big sails.
As you said , furling is a good solution and a easy way of refing. But keep it simple and strong. No Furlex in every case. Profurl is much better.
A own construction is also possible and you can make it for sailing every day of the year. All yachtfurls are not constructed for 250 days a year.
Beste regards
Jan Dijkstra edited 07:01, 6 Dec 2011
I would call your swing keels by the phrase 'keel housed off-centerboards'.
Leeboards increase lateral resistance without increasing draft. They address many (not all) of Mr. Dijkstra's objections. I've had considerable experience with them (admittedly in very small boats) and love 'em.
(See Phil Bolger's SIR JOSEPH BANKS, a similar project featuring leeboards, in Boats With an Open Mind.)
Alternatively, consider keel (a.k.a vortex) plates fixed horizontally along the bottoms of the keels. These prevent water from 'spilling' off the keel, keeping it running along the keel, increasing the keel's effectiveness. Additionally, they create turbulent vortexes when dragging laterally, resisting leeway.
I feel that avoidance of deep, fixed draft is a vital feature in servicing LDCs, many of whose lack or scarcity of deep water ports has contributed to their developmental deficit (for better and worse). Additionally, it allows relatively easy shoreside maintenance in areas absent haul-out facilities. edited 12:31, 12 Dec 2011
Thanks for all the thoughtful comments on the rig and (off-) centreboards. Opinions and suggestions from someone with your experience are especially valuable to us.
All of your ideas seem reasonable and correct. I have only to mention that we have considered all of them (even the squaresails) and would like to use many of them still. One problem is that we are not designing for sail performance alone. The rig must also be able to fold flat on deck for low clearance and upwind motoring. For these features, we are forced to accept extra windage and poor airflow. The ability to pick cargos from the bow and stern, very valuable in many expected applications, also reduces our options for the sail plan. We would very much like to fly more sail (especially since we will be sometimes using the dragging props to drive the motors as generators and charge the battery banks.) so the idea of a longer gaff is one we will be investigating.
Of course, you are right that we must focus on upwind performance. We expect to be able to motorsail most of the time, which will help some. Also, there are the off-centerboards. We will certainly discuss it again among the designers.
Please consider one design target - the capability of beach landing for loading and unloading. As Dave Zeiger says, ' ..a vital feature in servicing LDC's". To do this without losing much upwind ability has been a challenge us. The bilge keels will act much like the long shallow central keels you mention (perhaps more efficiently) when the ship is heeled. We could perhaps add a long shallow central keel as well. Maybe just in the forward sections.
You are right to say that we must avoid jamming the axes in their boxes. We are designing removable lids and overhead hoists to handle axe removal from within the hull. There must also be a robust release mechanism to allow the axes to fall back into the hull on contact. The windward axe will mostly remain unused, leaving the leeward, deployed one in a good position for quick retraction.
I know this is not ideal, but compromise is a constant companion in this kind of project.
I am quite interested in your ideas for a self-build furling gear, since we are aiming for durability and reliability under constant use. As a sailmaker, you might have some good ideas on how to design a flexible (it must be removed and stowed during cargo handling) yet robust furler. Something good for changing sails, as you wrote. Perhaps an oblong profile on the luff cable, so the sail will be twisted onto the cable when turned. A foil seems too rigid an option.
Very pleased to meet you, and many thanks for your expertise. I hope we can have you aboard when we get to, is it Nederlands?
Goede winden,
Pat
Thanks for your contributions. We briefly considered leeboards for their efficiencies, but it is precisely alongside that most cargo ships take their heaviest beating. We expect to be tying up on piers and walls of every size, as well as cargo operations over the sides.
The vortex keels are excellent for shallow draft work, but not so good for beach landings. Admittedly, that is also the weakness of the swing keel solution. We will have to have a design that leaves the keel bottoms well fortified when the axes are up and stowed. I will bring all these ideas into the next design meeting and post any new ideas here.
I sailed South and Southeast Alaska and look forward to dropping by again on the Greenheart.
I have also posted on your Open Contributions page here. Thanks for that too.
Pat edited 08:42, 19 Dec 2011
Flettner rotors ( magnus effect ) will supply 10 times the drive of the equivolent canvas sail area They can be retractable and low power demand. Main motors can produce enough electrical power to generate browns gas and feed tuned standard Gas ( petrol) motors with zero emmisions and no stored hydrogen. The cargo deck can be the bridge deck between the hulls and can be built Ro-ro. drop keels are best as they will be variable through water depths and maintain a good lift profile throughout the range. I would suggest end plates to protect the keel and hull (when grounded) and reduce pressure loss around the tip. The rugdders could be kick up from a protectd skeg with feathering or folding props.
A combination of shallow draft and low resistance would be a difficult combination to design but Cousteau's Mono-maran , is as close as you will get to covering these demands while producing good seakeeping and passaging making capabilities. I like the Mast frame to derek idea , and it has worked very well in many guises all over the world. for power Gaff works well but will not compare with the drive atainable with the Magnuss rotors. It is not a single answer that is required but a set of tools to give a skipper a drive and powering solution over all weather conditions and shipping constraints while still producing Zero GHG or particulates.
Solar alone is not YET efficient enough and the wind does not blow all the time , so you need a third spoke to the drive and that should be hydrolized water burned in an internal combustion motor ( relieable , safe ,commercial , and all thechnology is available right now )