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A Service-Pattern Sail Freighter: The Need For A Scalable
Open-Source Sail Freighter Design.
Steven Woods
The Center For Post Carbon Logistics
As sail freight gains traction in the sustainable shipping debate, there is a need for accessible and versatile coasting
ship designs capable of serving a wide variety of harbors, which can be built quickly and at relatively low capital
intensity. These vessels will then take over what would otherwise be transport by rail or road along the most
congested corridors in the US using near-zero carbon emissions propulsion. This not only reduces emissions from the
transport itself, it reduces congestion and makes the entire land transportation system more efficient and safe.
These vessels must be made to fit regulatory boundaries for captain licensing, length, tonnage, etc. There is a distinct
need for a Liberty Ship-like sail freighter specifically maximizing each step of the regulatory ladder to encourage the
building and operating of these coastal traders in the Northeastern US. The uninspected cargo vessel category is
already covered by a variety of simple and easily available vessel designs which can be modified for cargo use and
built inexpensively as Farmer’s Ships and other democratic pilot projects in plywood or other materials.
The proposed modular/scalable sail freighter design is still theoretical and requires the attention of a naval architect,
but lays out the requirements for such a set of vessels. By designing around regulatory and small harbor restrictions,
this design attempts to get the absolute maximum out of each category to allow for a rapid build-out of a coastal
sailing fleet. These vessels will be relatively low capital, require only small crews, and serve as a proving and
training ground for an expanding windjammer fleet. The proposed vessels will be single chine steel hulls in four sizes,
and with two possible rigs. A loaded draft of 6-8 feet allows for use of a wide range of harbors, single chine
construction in steel simplifies and speeds construction. The choice of simple gaff or marconi schooner rigs broadens
the applicable regions and trade which the vessels can effectively undertake. The application of roller furling and
modern winches keeps crew requirements relatively low.
Where designs which fit or nearly fit these requirements exist, they should be bought out (including any necessary
modifications) and made open source where possible. This set of designs may be a good starting place to make this
effort realistically possible and immediately implementable. Further work can be started from this foundation or
started anew, depending on where interest and funding can be acquired.
KEY WORDS: Sail Freight; Small Vessels; Coastal Trade;
Open Source; Wind Propulsion.
The use of sail freight for displacing cargo from land based
modes to seaborne zero emissions transport is a viable and
historically proven way to reduce energy requirements and
carbon emissions. The theoretical economic and emissions
benefits of wind propulsion for large vessels on transoceanic
routes has already been established by several studies (Perez,
Guan, Mesaros and Talay 2021; Wind Ship Development
Corporation 1981), but there has been little attention paid to the
potential carbon offsetting available from coastal trade under
sail (Woods and Merrett 2022). The use of sail in coastal trade
reduces particulate emissions, noise pollution, traffic congestion,
and their associated medical and climate impacts in both port
areas and directly inland (American Society Of Civil Engineers
2021). These are desirable in terms of transport decarbonization
and as a form of jobs program for the maritime trades, however,
the main bottleneck in the short- to mid-term will be producing
a sufficient fleet of windjammers to take up the cargo necessary.
For example, New York City, if provided with its minimum food
needs by sail, would require around 2 million tons of shipping.
The majority of current sail freighters worldwide are refit
vessels which were built many decades (and come over a
century) ago, and the supply of these vessels is extremely
limited. Even including the addition of rigs to motor vessels
below 300 tons as was accomplished with the currently-serving
SV Kwai and others during the 1970s Oil Crisis, there are few
remaining vessels to be converted (Satchwell 1986).
Construction of a large fleet in a short time will be necessary to
A Service-Pattern Sail Freighter SISDO 2023, 6-7 November, Glen Cove and King’s Point, NY
Steven Woods
ensure there is sufficient transport capacity to feed major cities
without cooking the planet (Woods 2021).
There are few available plans for sail freight vessels currently
available, and most of these are optimized for sailing, as
opposed to getting the maximum out of the restrictions they will
have to operate under. These restrictions come not from harbor
depths, air draft, or other physical restrictions, but principally
from regulatory barriers such as inspection requirements,
captaincy license categories, and the availability of trained crew.
These constraints will likely be the main things which need to
be kept in mind, and designed around. The second priority is to
design for simple, rapid construction of a large fleet. These
regulatory hurdles can be maximized as much as possible
through good design around these constraints before others.
Vessels under 15 GRT and 40 feet in length fall under the
heading of Uninspected Cargo Vessels, and should be included
in this design process for a number of reasons. These are already
covered by a number of designs suitable for backyard
boatbuilding, such as a number of plans by George Buehler
(Buehler 1991), Bruce Roberts (Roberts, n.d.), and the now
open-source plans of the Vermont Sail Freight Project’s sailing
barge Ceres (Woods 2023a). These (very) small vessels are well
suited to the role of Farmer’s Ships (Shaw 1939), feeder vessels,
operations in low volume trade routes, and where unlicensed
sailors are the only crew available. They are a form of
democratic and egalitarian sail freighter which will likely
proliferate in the near future, especially as scout ships
establishing trade routes. In many ways, these are frontier
vessels like the Scow Schooners of the 19th century Great Lakes
and other locations, mostly made where low capital reserves and
limited skill were the limiting factor in shipbuilding (Martin
2018), and will likely have an economic role similar to the
Galway Hookers of Northwestern Ireland (O Sabhain 2019).
However, they cannot reasonably take up the strain of longer
trunk routes, high-volume packet routes, or transoceanic trade
where the larger Service-Pattern vessels will have a more
prominent role.
Despite the passing of the 1969 convention on tonnage
measurement of ships, US regulations are still written using
Gross and Net Register Tons of 100 cubic feet each for
regulatory purposes (USCG Marine Safety Center 2022). There
have been a number of ship designs based around maximizing
profits through manipulating multiple tonnage systems; in many
cases this has both endangered ships and their crews (Vasudevan
2010). This should be avoided for any open-source sail freighter,
as the maximization is not for profits, but the optimal use of
captain’s licenses. Care should be taken to make these designs
compatible with STCW and other similar regulations, including
measurement under the 1969 Convention rules; this makes for
simpler regulatory compliance and easier adoption worldwide.
Keeping lengths under 24 meters, for example, solves two
problems: The vessels need not be measured under the
Convention rules, and most STCW/SOLAS regulations will not
apply (USCG Marine Safety Center 2022). Similarly, for
inclusion under USCG subchapter T regulations the vessel must
be under 65 feet in length, which may be quite possible for the
25 and 50 GRT vessels described in this paper. As the vessels
grow larger, they will need to abide by progressively stricter
regulations, but these vessels will require a much higher capital
outlay regardless, and their crews will need to become
progressively more professional. This is a good thing and these
regulations exist for very good reason; however, there is no
reason to have a potentially viable ship design become
unavailable to a sail freight endeavor simply because it is two
feet too long or 1.5 GRT over a regulatory limit as is the case
with some designs discussed in this paper.
The proposed service pattern sail freighters should fit the
available licenses, all of which are up to the tonnage limit. This
means each should be just barely shy of the targeted number, for
example 14.9/24.9/49.9/99.9 GRT, but labeled for convenience
at the next full integer. As they are designed as coasters, there is
less worry about STCW requirements, though compliance
would not be amiss for the larger vessels as it will open up
further markets. The basic requirements of the designs are as
follows:
SERVICE-PATTERN SCHOONER REQUIREMENTS:
☛ 4 Hull varients: 15GRT/25GRT/50GRT/100GRT
☛ 2 Rig variants: Schooner (Marconi and Gaff).
☛ ≤ 9 foot loaded draft.
☛ CDWT of at least 7.5/15/35/70 tonnes at Stowage Factor of
2.6 m
3
/tonne.
☛ Simplified, inexpensive, rapid construction in steel.
☛ 15/25 GRT model should include scantlings for plywood
home builds.
☛ Under 65 feet LOA where practicable (T-Boat Regulations).
☛ Sufficient motor power for docking and emergency use.
☛ Small enough fuel or energy storage to prevent reliance on
motoring.
☛ Optimized for breakbulk/ palletized/ super sack (non-
containerized) cargo.
☛ Sufficient ship’s gear to handle palletized drafts to and from
the dock.
☛ Use of roller furling, winches, etc. to reduce crew
requirements.
A Service-Pattern Sail Freighter SISDO 2023, 6-7 November, Glen Cove and King’s Point, NY
Steven Woods
Single chine construction and avoidance of complex curves
wherever possible will make the construction not only faster, but
simpler and possible without a large amount of specialized
equipment. The technique employed in the designs of the
INDOSAIL system proposed in 1985 at the ADB Conference on
Wind-Assisted Propulsion of employing different center
segments for an otherwise identical vessel, making it effectively
modular, is worth considering where possible (Wiriadidjaja and
Schenzle 1985). This may not work for all 4 possible vessels
and may require creating a small and large size ship instead,
which uses different central segments, but the same bow and
stern, aiding mass production and design efforts.
By keeping the crew requirement low through the application of
winches and other mechanical aids, the cost of operation will be
kept to a reasonable minimum, an important consideration for
these vessels as the energy transition is in early stages. As the
freight rates of trucks and trains are kept artificially low by a
number of factors (Austin 2015), and these are the modes which
coastal and inland trade will be competing against (Woods and
Merrett 2022), labor aboard these vessels must be kept to a safe
minimum. Additional crew members who are included simply
for hauling on lines make no sense when winches can do the
same job reliably for a fixed initial cost.
These vessels should be able to provide a wide range of services
on varied waters and at varied levels of capital intensity. They
can be grown with the fleet’s demands and the captain’s license
tonnage, while serving as training vessels for new crew
members. The most common types are likely to be 50 and 100
GRT vessels. However, the inclusion of the 25 GRT vessel is
important due to the likely prevalence of 25 GRT Masters when
compared to other license types. These smaller schooners will
also have a role to play as feeder vessels, training platforms, and
scouting ships for new markets, so their construction should not
be ignored or belittled in favor of the more capital intensive
larger vessels.
The use of traditional sail and traditional rigs is well supported
in this role by several factors: Traditional sail is well
understood, has low capital requirements, and performs well in a
wide variety of conditions (Scott 1985). In the sizes of vessel
dealt with here, not all crew need be licensed, which simplifies
most recruitment issues which might arise. There are a wide
variety of training programs through commercial and
recreational associations on the handling of traditional sail in a
racing or cruising context, as well as training on square rig
sailing from organizations such as Tall Ships America. Trained
sailors will therefore be easier to find for these vessels than for a
flettner rotor equipped ship, and the rig will be more affordable
overall. The strategic materials and energy requirements of
traditional rigs are also low, making them a more climate
positive option than complex systems better left to larger vessels
(Woods 2023b). Schooners are a highly efficient rig in terms of
crew requirements, an in 1906 averaged a crew of 5 and 42.9
Tons Per Sailor, though they ranged from 10-4914 Net Register
Tons, across a sample of 5,947 vessels (see Fig 2) (Woods
2021). On a less objective note, there are also few things more
worth watching than a traditional sailing vessel making its way
up the coast, and this romantic, esthetic appeal may well be a
significant influence on getting a sufficient mass of people
behind the sail freight movement to keep it commercially viable.
Flettner Rotors, Wing-Sails, and other modern wind propulsion
systems lack this particular quality.
Figure 1: Schooner Illustration from Mee and Thompson, The
Book Of Knowledge 1912.
Figure 2: Image from Woods (ed), Sail Freight Handbook pp 35.
CC-BY-NC-ND 4.0.
A Service-Pattern Sail Freighter SISDO 2023, 6-7 November, Glen Cove and King’s Point, NY
Steven Woods
There are similarities between the proposed Service Pattern
vessels and oil-crisis era vessels, such as those proposed for use
in the Kingdom of Tonga (Palmer and Corten 1985), among
others. Some of these designs already effectively exist, and can
be purchased into the open source field without much further
modification or effort beyond funding the purchase. For
example, Tad Robers has a cargo schooner design which fits
these requirements, but at 60 feet the larger design is 28.6 GRT,
as opposed to the 25 which should be targeted (Tad Roberts
Yacht Design n.d.). The proposed Electric Clippers of Derek
Ellard are specifically designed for mass production, and fit
some of these requirements as well at various sizes (Ellard
2020). The River Sea Ship designed by Trans-Tech Marine for
NYSERDA in 2015 is a similar idea, and currently open-source
(Uttmark 2015). Another open source design by the Greenheart
Project is slightly too large for the 100 GRT license
(Scherpenhuijsen Rom Et Al 2021). A cargo schooner design by
Thomas Colvin, found in his book Steel Boat Building, is
available but not only exceeds the Uninspected Cargo Vessel
parameters for length overall, it carries only 7 tons of cargo,
making it effectively uneconomical due to initial cost and
possible revenue with such a small hold capacity in a
license-demanding vessel size (Colvin 1985). The use of
unmodified historical designs, while viable, are still unlikely to
max out the regulatory categories necessary to maximize the
utility of a modern fleet (Davis 2012).
Avoiding cargo containerization for these vessels is an important
point. Not only is moving containers a waste of space and
energy (Woods 2023b), it is inefficient at this scale of operation.
Palletization should provide all the necessary efficiency gains
from unitization without a significant investment at every port to
handle containers. Specifically, the Euro-Pallet dimensions
should be used due to their provision for full and half pallets
which can be used according to the ship’s hold size (EPAL n.d.).
Ship’s gear can handle palletized or breakbulk cargo without a
significant challenge or supporting infrastructure, a critical
consideration when small ports are just re-establishing cargo
operations (Woods 2023a; Koltz 1980), with the additional
benefit of loading and discharging cargo in a fifth of the time
needed for breakbulk handling (Goertz 1976). Most
commodities which are easily shipped by sail freighter can be or
are shipped with the highest economic efficiency on pallets or in
super sacks, as this reduces labor and handling significantly
compared to breakbulk handling. As sailors will likely have to
be their own dockers through the early stages of the sail freight
resurgence, there is a great advantage to be found in reducing
dockside labor wherever possible. For short-sea container
traffic, other designs will be needed, such as the Electric Clipper
180 designed by Derek Ellard (n.d.).
With the smallest Oceans license granted by the US Coast Guard
being 200 GRT, and this being applicable to near-coastal waters
as well, it would be logical to extend the design to 200 GRT.
This would require further regulatory compliance work, such as
meeting STCW requirements. These vessels would likely be
involved in mostly longer distance trade such as long coastal
runs between larger ports, and transoceanic trade in coffee,
alcohol, and other high-value cargo in the early stages of their
deployment. Whether a single chine simplified design for these
larger vessels would be wise is a question for naval architects to
answer. Vessels over 100 GRT should not be considered a
priority for the early stages of this effort, however, and can be
derived from the initial designs at a later date if needed.
A prudent designer for these vessels might also apply the same
principles to canal boats, fitting them to the dimensions of the
New York State Canal and other significant inland waterway
lock and prism dimensions. The 15/25/50/100 GRT steps to suit
captaincy requirements, and keeping to less than 65 feet
whenever possible to stay under T-Boat regulations will still
apply; the greatest variation will be in the powering of the hulls
and energy storage for a preferably electric motor vessel. Use of
Lead-Acid batteries as dual-purpose ballast and a generous
amount of charging capability should be included, by whatever
means are available. Placing ship’s gear in a tabernacle or other
foldable mounting will also be important anywhere there are air
draft restrictions, such as the 14 foot limit on the New York
State Canal System. Again, some designs which can be adapted
or used directly already exist, such as the River Sea Ship by
Trans-Tech Marine, but they are not optimized for the regulatory
categories treated in this paper (Uttmark 2015).
Similarly, for areas where a transition between canal and more
open water environments are going to be frequent, such as the
New York State Canals in the Central New York and Finger
Lakes Regions, as well as small routes in many other areas, a
derivative of the Norfolk Wherry would be in order. This vessel,
if copied at similar tonnages (15/25/50) provides several
advantages in its design for vessels in and out of canals
frequently, notably the counter-weighted mast and tabernacle
arrangement which made sailing in canals and the Broads viable
(Wherry Maud Trust n.d.). For this particular vessel, removing
or adding central hull sections to the same plan (with associated
changes to the rig) will be a useful design feature to adopt, and
will reduce work considerably. Their easily flattened Cat rig,
when paired with an electric motor, would make traffic in areas
A Service-Pattern Sail Freighter SISDO 2023, 6-7 November, Glen Cove and King’s Point, NY
Steven Woods
like the intercoastal waterway, New York Canal system, and
areas with frequent change between canal and lake operations
possible mostly under sail. This means a lower capital
expenditure, lower shore power demand, and lower strategic
material commitments for these feeder fleets. Air Draft should
be kept to 12 feet or less with the mast down, with a maximum
length of 64 feet and a shallow draft. If carefully thought
through, a solarized motor-only version of this wherry could
serve as the canal boat described in the above paragraph.
Spud Barge Depots and other infrastructure components which
will need to be deployed in the near future, and will not require
a significant amount of effort for naval architects, should also be
developed and published (Woods 2023a). A Service-Pattern
Barge Depot given in three sizes, for example 40, 80, and 120
feet in length, with a beam set at 50% of the length for a simple
barge would be a few day’s work to factor out the scantlings and
instructions to make local construction without specialized
facilities or tools possible. These barge depots should be
designed for plywood or steel construction as economic
pressures demand, based on the size of the barge.
By creating a ready and publicly available set of sailing vessel
designs which take maximum advantage of regulatory
categories, there is a better chance of getting as much capacity
as possible out of any small vessel fleet and crews. There is a
need for these vessels worldwide, from the South Pacific islands
to New York Harbor, and the longer it takes to make these vessel
plans available and build them, the worse the transport situation
will become in terms of carbon emissions and congestion before
any significant improvement can be made. Potentially thousands
of jobs on and off the boats are waiting to be created for this
project, and what’s needed to start the industry along is a
reasonable set of ship plans.
BIBLIOGRAPHY:
American Society Of Civil Engineers. 2021 Report Card For
America’s Infrastructure: A Comprehensive Assessment Of
America’s Infrastructure . Reston: ASCE, 2021.
https://infrastructurereportcard.org/
Austin, David. Pricing Freight Transport to Account for
External Costs . Washington: Congressional Budget Office,
2015.
https://www.cbo.gov/sites/default/files/114th-congress-2015
-2016/workingpaper/50049-Freight_Transport_Working_Pa
per-2.pdf.
Buehler, George. Buehler's Backyard Boatbuilding . Camden:
International Marine, 1991.
Clark, Roy. Black Sailed Traders Keels: and Wherries of
Norfolk and Suffolk. London: David & Charles, 1972
Figure 3: From Clark, Black Sailed Traders: Keels and Wherries
of Norfolk and Suffolk . London: David & Charles, 1972
Figure 4: From Clark, Black Sailed Traders: Keels and Wherries
of Norfolk and Suffolk . London: David & Charles, 1972
Figure 5: From Sail Freight Handbook 2nd Edition. Pp 170.
CC-BY-NC-ND 4.0
A Service-Pattern Sail Freighter SISDO 2023, 6-7 November, Glen Cove and King’s Point, NY
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Colvin, Thomas. Steel Boat Building . 2 Vols. Camden: Internat’l
Marine Publishing Co, 1985.
Davis, Charles G. American Sailing Ships: Their Plans And
History Mineola: Dover Publications, 2012.
Ellard, Derek. "Electric Clipper 100." . Accessed 30 November,
2020. www.gosailcargo.com .
EPAL. “Load Carrier Overview.”
www.epal-pallets.org/eu-en/load-carriers/overview
Accessed 14 May 2023.
Goertz, Janice. “Unitization in Distribution” in Business
Logistics P.M. VAN BUYTENEN (Ed.) The Hague:
Martinus Nijhoff, 1976. Pp 210
Koltz, Bruce George. “The reintroduction of sail for marine
commerce: and the consequent effects upon small port
economy and trade routing” Master’s Thesis, University of
Notre Dame, 1980.
https://calhoun.nps.edu/handle/10945/19039
Martin, J. C. “‘Scows, and barges, or other vessels of box
model’: Comparative capital investment in the sailing
scows of the Great Lakes of North America and in New
Zealand.” Int’l Journal of Maritime Hist , 30(1), 2018.
89–105. doi.org/10.1177/0843871417746290
Mee, Arthur, and Holland Thompson, eds. The Book of
Knowledge (New York, NY: The Grolier Society, 1912)
Ó Sabhain, Pádraig Seosamh. “The centrality of the Galway
hooker to dwelling in the island and coastal communities of
south west Conamara.” PHD Thesis. NUI Galway, 2019.
https://aran.library.nuigalway.ie/handle/10379/15935
Palmer, C. and E.M.J Corten “Preliminary Design Study Of
Intraisland Transport Vessels For The Ha’apai Group Of
Islands In The Kingdom Of Tonga.” Pp 133-172
Proceedings of Regional Conference on Sail-Motor
Propulsion. Manila: Asian Development Bank, 1985.
Perez, S; Guan, C; Mesaros, A; Talay, A, “Economic Viability
of bulk cargo merchant sailing vessels” Journal of
Merchant Ship Wind Energy , 17 August 2021.
www.jmwe.org/uploads/1/0/6/4/106473271/jmwe_17_augu
st_2021.pdf (Accessed 22 Jan 2022)
Roberts, Bruce. Roberts Yacht Design . https://bruceroberts.com/
Accessed 14 May 2023.
Satchwell, C.J., “Preliminary analysis of of log data from the
Fiji windship ‘Cagidonu’” Ship Science Report No. 24
(University of Southampton, April 1986)
www.wind-ship.org/en/research/
Scherpenhuijsen Rom, Erik, Et Al. “Evaluation and Adaptions
to the Greenheart Project zero-emission vessel for service in
the Pacific Islands.” International Journal of Maritime
Engineering 163:A4 (2021)
www.intmaritimeengineering.org/index.php/ijme/article/vie
w/735
Scott, H.F. Morin. “The Case For Traditional Sail.” Journal of
Wind Engineering and Industrial Aerodynamics 19(1-3),
(1985) 335-349. doi.org/10.1016/0167-6105(85)90068-6
Shaw, Earl B. “The Aland Islands.” Economic Geography 15,
no. 1 (1939): 27–42. https://doi.org/10.2307/141003.
Tad Roberts Yacht Design. “60 Ft Cargo Schooner”
https://www.tadroberts.ca/services/new-design/sail/steelcarg
oschooner60
Uttmark, Geoff. Eriemax: Assessment of Green Ship
Technologies and Plan for Deployment on the Erie
Canal/NYS Barge Canal System New York: NYSERDA,
2015.
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Measurement . Washington: US Coast Guard, 2022.
https://www.dco.uscg.mil/Portals/9/DCO%20Documents/M
arine%20Safety%20Center/Tonnage/Tonnage%20Guide%2
01%20-%20Simplified%20Measurement.pdf
Vasudevan, Aji. “Tonnage measurement of ships : historical
evolution, current issues and proposals for the way
forward” Master’s Thesis. World Maritime University,
2010. https://commons.wmu.se/all_dissertations/214/
Wherry Maud Trust https://wherrymaudtrust.org/ Accessed 15
June 2023.
Wind Ship Development Corporation, Wind Propulsion For
Ships Of The American Merchant Marin e Norwell, MA:
WSDC, 1981.
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s_of_the_America.html
Wiriadidjaja, S., and P. Schenzle. “The Indonesia-Federal
Republic Of Germany INDOSAIL Project.” Pp 269-306
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Woods, Steven, and Sam Merrett “Operation of a Sail Freighter
on the Hudson River: Schooner Apollonia in 2021.”
Journal of Merchant Ship Wind Energy 2 March 2022.
www.researchgate.net/publication/358971392
Woods, Steven. “Sail Freight Revival: Methods of calculating
fleet, labor, and cargo needs for supplying cities by sail.”
Master’s Thesis. Prescott College, 2021.
www.researchgate.net/publication/354841970
Woods, Steven, (Editor). The Sail Freight Handbook 2ed.
Kingston: Center for Post Carbon Logistics, 2023.
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For Climate Crisis Response." Proceedings Of The
Conference On Small Scale Inland And Coastal Sail
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www.researchgate.net/publication/369033136
A Service-Pattern Sail Freighter SISDO 2023, 6-7 November, Glen Cove and King’s Point, NY
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APPENDIX: OPEN SOURCE SAIL FREIGHTER REQUIREMENTS.
All Schooners + Barge Depot + Wherry.
☛ Plans will be released into Public
Domain/CC-BY-SA 4.0 in their entirety, as
one set, via CPCL and likely the IWSA Small
Vessels Publication.
☛ Plans to include Lines Plans, General
Arrangement, Sail Plan(s), Stability Curves.
☛ Vessels max out just below 15, 25, 50, 100
GRT, designed for fast, easy construction.
☛ All vessels to be provided with ship's gear for
cargo handling as specified.
☛ Palletized and breakbulk cargo only. No
provision for containers at this scale.
☛ Target Stowage Factor to be 80 Cu Ft per short
ton; 2.5 Cu M per Tonne.
☛ Outfitting should be made as work-boat and
simple as possible. The owners can provide
for more comfort if they decide it is
necessary.
☛ Ship Class Designation: OSSF [GRT]
Open Source Sail Freighter 15:
☛ Under 40 ft and 15 GRT
☛ Preferably 32-36 feet LOA with 40 ft LOS, if
possible, to reduce capex/opex.
☛ Designed specifically for home-builds in
plywood or steel (Beuhler or Roberts type
plans). This requires a bit more detail and
instruction than the others which will be built
exclusively by shipyards. To include
construction drawings, materials list, welding
hours estimation.
☛ Minimally complex rig: Marconi or Gaff
Sloop (preferably both options provided) with
basic sailing skillset in mind. Self-tacking jib
highly encouraged.
☛ Tabernacle and keel-stepped mast options if
possible.
☛ Minimum 7 CDWT, preferably more, but not
to exceed 14.9 short tons. 17.5 cu m.
☛ Hold and gear compatible with half
Euro-Pallets loaded to 125kg.
☛ 2 crew design, with 3rd provided for in pilot
berth or hammock.
☛ Design for minimal expense and low
maintenance.
OSSF 25:
☛ Tabernacle rig or keel-stepped.
☛ Under 65 feet.
☛ Minimum 15 CDWT. 37.5 cu m.
☛ Hold and gear compatible with half
Euro-Pallets loaded to 125kg.
☛ 2-4 Crew. 2 Watches of 2 people preferred.
OSSF 50:
☛ Tabernacle Rig as an option possible,
otherwise keel-stepped.
☛ Topsail schooner option with roller furling
would be nice, but not required.
☛ Under 65 feet if possible.
☛ Minimum 30 CDWT. 75 cu m.
☛ Hold and gear compatible with Euro-Pallets
loaded to 250kg.
☛ 4-6 Crew. 2-3 Watches of 2-3 sailors.
OSSF 100:
☛ 9-12 Crew (3 watches of 3-4 sailors)
☛ Under 79 ft LOA if at all possible.
☛ Minimum 60 CDWT. 150 cu m.
☛ Hold and gear compatible with Euro-Pallets
loaded to 500kg.
OSSF-B: (Barge Depot)
☛ Designed to be linked together into the size of
depot required. Not always permanent
infrastructure, so an easily towable design
would be useful.
☛ Preferably 60 feet long, 40 feet wide for
working space.
☛ 4+ Spuds sufficient to hold in protected
waters.
☛ Distribution pattern on deck for warehousing
containers without destabilization.
☛ Cargo Handling Gear comparable to OSSF 50.
OSCW 15/25/50 (Open Source Cargo Wherry)
☛ 12 ft Air Draft with mast down and 6 foot
maximum draft.
☛ Electric propulsion with multiple charging
options preferred.
☛ Cat Rig and Counterbalanced mast as with
originals.
☛ Marconi and Gaff Rig Variants, Marconi
paired with roller furling into Mast.
☛ Requirements otherwise as with OSSF of same
tonnage.
☛ Unrigged Variant with maximized solar panels
for regions with unfavorable winds.
A Service-Pattern Sail Freighter SISDO 2023, 6-7 November, Glen Cove
and King’s Point, NY
Steven Woods