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40 Meter
Arabian Cargo / Passenger Dhow
131' Length On Deck
Perspective Forward | Perspective Aft
Perspective Far Aft Sailing | Perspective Aft Sailing | Perspective Side Sailing
Copyright 2016 Michael Kasten
The Dhow in History
The 40 meter vessel shown here is modeled after a type of traditional Arabian Dhow, most closely resembling the Sambouk and Baghala types. The most traditional rig for this kind of vessel is the Settee rig (trapezoidally shaped sails) or the Lateen rig (triangular sails). Both of these rig types are able to sail down wind like a square rig, but they are also able to sail well to windward and tack into the wind like a fore and aft rigged craft.
Most sources attribute the origins of the Dhow to India, where it appears they were built near the supply of wood. Originally the Dhow and other craft in the region were built using stitched-together planks, and on some smaller local craft that kind of construction can still be found.
The Dhow was developed over many centuries as a trading vessel, carrying cargo east as far as China by way of Sri Lanka and the Straits of Malacca, bringing goods to and from Alexandria via the Red Sea, thus connecting the Roman Empire with the Han Dynasty in China. The Arab trade routes also extended south to Zanzibar in Africa. Some sources claim that the very earliest craft were trading along similar coastal routes in the Indian Ocean as early as 3,000 B.C. These craft eventually developed into the Dhow as we know it today.
With the triangular Lateen sail, the Dhow could out-sail the square rigged craft of the Mediterranean, and better navigate the contrary winds of the Red Sea. With knowledge of navigating by the stars passed down from the Egyptians, the use of the magnetic compass learned from the Chinese, and the stern mounted rudder of the Chinese Junks, the Dhow was well equipped to dominate the Indian Ocean trade routes during the last 2,000 years.
Thus, the Arab merchants must be given due credit, having made longer voyages than Columbus nearly fifteen hundred years before Columbus sailed toward the new world.
The features that distinguish the Dhow are its Lateen or Settee rig, and typically a double ended hull form. Other features that have come to characterize the Dhow are the long raked bow, and the high and relatively upright stern. In some forms such as the Baghala, and the Shuw'i (or Shu Ai) the stern was widened into a massive wide transom often carried right down to the waterline. In other types, the hull was more or less double ended, but often a platform extended over the stern, much like the Indonesian sailing Pinisi (which seems to have been derived from the Dhow in terms of its hull form and structure).
Click for Larger ImageThe Dhow as a Cargo / Passenger Yacht
The sailing Dhow shown here has been designed with a new purpose... that of being a "Cargo Yacht" that is able to carry a few passengers. In this case, the intent is to carry 8 crew including the officers in four cabins, plus four passengers in two cabins. An alternate interior could transform the 'cargo hold' into four to six luxury suites for charter guests.
Since the Dhows are identified by their hull form rather than by their rig, it seems that this design most closely resembles the types of Dhows called the Baghala and the Sambouk. The stern has ample width, and is tucked up high to stay out of trouble in a following sea, a feature common to the sea-going Sambouk types.
The aft deck extends beyond the lower transom just enough to house the rudder head, so that a tiller or wheel can be arranged easily. It is common among traditional dhow types to have long raking rounded stem, which when finished off with the high curved stem timber seems to resemble a scimitar…! Balanced with “davit” boards that extend from the stern, the result is both functional and well balanced.
In terms of its structure, the Dhow is very much the same as the Indonesian sailing Pinisi types, which are outlined on our Pinisi History web page. It is assumed by many that the dhow was in fact the inspiration for the Pinisi craft of Indonesia.
If tradition were to be followed faithfully, the rig for this vessel would be designed in keeping with a typical sailing Dhow, in other words having a Lateen or Settee type of rig. However, the rig we have chosen for this vessel is that of the French Lugger... an eminently practical rig that is capable to windward as well as being very well adapted to running off the wind.
Particulars
- Sparred Length: 66 m
- Length of Hull Structure: 44.9 m
- Length on Deck: 40 m
- Length on WL: 34.3 m
- Beam: 12 m
- Draft: 3.9 m at DWL
- Displacement: 430 metric tons
- Measurement Tonnage: 240 (approx.)
- Average Immersion: 2.8 MT / cm
- Length of Hold: 14 m (45') minus bulkhead thickness
- Depth of Hold: 3.4 m to sole
- Breadth of Hold: 11m at deck
- Volume of Hold: 425 m^3 (approx.)
- Sail Area Lowers: 892 m^2 (preliminary)
- Sail Area Total: 1,225 m^2 (preliminary)
- Theoretical Max Hull Speed: 15 knots
- Horsepower Required for 15 knots: 2,200 hp
- Maximum Efficient Speed Under Power: 12 knots
- Horsepower Required for 12 knots: 1,200 hp
- Maximum Speed Potential Under Sail: 14.5 knots
- Average Sailing Speed: 10 knots
- Maximum Topmast Height: 40 m
- Maximum Lower Mast Height: 29 m
The topmasts are arranged so they can be easily lowered should the need arise, for bridge clearance. All of the above is accurate according to the model, however the model is preliminary and in all likelihood will change in many ways as the design is further developed.
The Interior Layout
At 40 meters (131') over the range of the deck, the design is perfect for a couple to live aboard permanently, to carry cargo or supplies to remote locations, and to also accommodate four or more guests in two separate suites. An alternate interior would easily transform the 'cargo hold' into four to six luxury suites for charter guests.
The cargo hold is centered at the average center of buoyancy, so loading of equally dense cargo should produce zero trim. Based on its use as a combination cargo / passenger vessel, the layout that seems best is as follows, starting forward:
- Right forward is the forepeak / chain locker with a WT bulkhead aft.
- Aft of the WT bulkhead, on the upper level is a four-berth Crew Cabin.
- Below that is a Bosun’s locker / workshop, with tanks below.
- Aft of the Bosun's locker are two en-suite double-berth Guest Cabins, one to port, one to starb’d.
- Below the Guest Cabins are fuel and water tanks.
- Aft of the Guest Cabins is the Cargo Hold.
- Above the Cargo Hold on the midship deck aft is the Galley.
- Aft of the Galley on the upper level is a Dining Room and Lounge on center.
- Outboard of the Dining Room are single berth cabins outboard to port and to starb’d for the mechanic and cook.
- Below the Dining Room are the Engine Room and mechanical spaces.
- Outboard of the on-center Engine Room are two mechanical spaces for generators / service equipment / laundry / etc.
- Below the mechanical spaces are fuel tanks.
- Aft of the E.R. / Lounge is a Bridge / Pilot House on deck.
- Below the Bridge are the officer’s quarters, i.e. double for the captain, single for the mate.
- Below the officer’s quarters is a storage area for food and supplies.
Preliminary Rig
The preliminary model shows a French Lugger rig sized for optimum sailing. The French Lugger rig has a low center of effort, which is all to the good with regard to stiffness under sail.
I did not bother to optimize the rig beyond creating this preliminary model. An example of what could be improved is that it would be very favorable to have three sails on the forward and main masts, and three yards – as was done on the French Lugger GREYHOUND. That would make each individual sail much more manageable.
Of course the rig is highly preliminary and can be changed as needed to accommodate other preferences. Other rig options that might be considered are a gaff rig, a brigantine rig, or a Chinese Junk rig. Each have their advantages and romantic appeal…
More Information...
An interesting article on our work with the wooden vessels of Indonesia appeared in the New York Times, called The Traditional Pinisi - And Then Some. For a taste of what is possible with these craft, please see our Dunia Baru web page where you will find excellent as-built images.
If this or a similar traditional sailing yacht is of interest, regardless of its cultural heritage, we offer a complete design service from concept to launch. Our preference is to use traditional methods and styling to the maximum extent possible; to design the structure to classification society standards; and to assure that stability and sea keeping are up to IMO standards for worldwide travel.
We can accommodate a variety of requests, for example to change the size, to alter the styling, or to modify the layout as needed. For complete information about our work with these vessels please see the following links, or for more information please inquire.
Our articles about building an Indonesian Pinisi or KLM:
Pinisi History | Pinisi Building | The Ultimate Charter Pinisi
Sailing vs. KLM Types | A Cargo Pinisi as a Yacht...?
Pinisi and KLM designs that we have created or have planned:
30m Pinisi, DATU BUA | 36m Pinisi, SILOLONA
38m Pinisi, AMANDIRA | 50m Sailing Pinisi
27m DIVE Charter KLM | 30m Charter KLM | 33m Charter KLM
36m KLM, DUNIA BARU | 40m Charter KLM | 50m Charter KLM
Descriptions of our adventures with these boats:
Silolona "Homecoming" | Indonesia Boatbuilding Images
Five Schooners and Two Arabian Dhows Suited to Building in Indonesia
17m Flores Privateer | 20m Sulawesi Privateer | 31m Komodo Privateer
36m Tern Schooner | 36m Lombok Privateer | 45m Kalimantan Privateer
22m Arabian Baghala | 36m Arabian Baghala
Two junk rigged KLM types for construction in steel:
25m Lady Destiny | 55m Lady Destiny
Please see the AVAILABLE BOAT PLANS web page.
Home | Intro | Our Design Process | Stock Design Info | Motor Yacht Designs | Sailing Yacht Designs | Prototype Designs
Plans List | Articles | Our CAD Design Stream | Maxsurf | News..! | SITE MAP..! | Site Search | Design Team | Contact Us
