Carónnae Barge

Those fuckers thought they'd take our river travel away? Hate to be them now!

— cheery carónnae sailor

Carónnae barges are adaptations of traditional trade barges used by the Arriusi that can not only sail on water, but may also change into vessels also capable of travelling on land.

Name-Bonding by Hanhula (via Midjourney)

Traditionally, the Arriusi exclusively travelled along rivers, with the water doing a large majority of their transport work. It was unnecessary for them to hire livestock and switch to land travel, and those that wanted their goods would travel to their locations to purchase it.
Due to the damming of the Imbreagat and to changing conditions along their existing trade routes, it has become increasingly difficult for the Arriusi to maintain their traditions. Even in times long past, there were challenges: travelling through a country at war could see them attacked or taken prisoner, and they were at the utter mercy of the weather's fury.
Countless Arriusi have been lost over the years to unpredictable devastation on the river, with little way to escape it. Those who survived these times often did so without their belongings, forced to watch their homes and livelihoods sink - or be destroyed at the hands of newfound enemies.

The carónnae, as they are often abbreviated, are a relatively recent invention from a group of Arriusi craftspeople known as the Cravillaret, who largely dwell in the small Vostene river-town of Póltinou. They are designed to prevent this historical inevitability by allowing the Arriusi to remove their boats from the water with ease, transitioning to land vehicles where necessary and continuing their journeys with far less risk.

Functionality & Propulsion

A standard river barge is a flat-bottomed boat, usually of wooden construction, that is propelled forth by the combination of the water's current and their vast sails. Carónnae, when converted, lose half of this - the water - and must instead adapt to more usual forms of travel over land. This was the chief engineering concern the Cravillaret had to address to go beyond the prototyping stage, and its initial accomplishment proved vital for the development of carónnae.

Essentially, the barges are modified through a series of folding wheel-like mechanisms underneath. When the barges are setting sail on the water, these mechanisms are kept inside watertight hatches lined with waxed sail-like material to protect them from erosion and water damage, and to prevent the barges from developing leaks.
When a barge needs to convert to land use, it must first be moored against a slope, and these new wheels must be activated.
These new sets of wheels are triangular in shape and around their metallic structure are heavily-textured treads made from specially-coated metal. When one is placed upon a hill and activated, it begins a climbing motion that gradually pulls up the entire barge; once all wheels are on land, these initial wheels are left in place only briefly.

Carónnae Wheel Plans by Hanhula

For most land use, the barges instead use a great number of wood-and-metal wheels designed to handle impacts almost as a wagon might, also stored into hatches in the barge's flat bottom. Once the wooden wheels have been deployed, the heavier-duty set is withdrawn - they are only used again to navigate over particularly challenging obstacles.

Prototype Wagonbarge by Hanhula (via Midjourney)

The wind is still the driving force of propulsion for a barge once its wheels are properly deployed, but it may be assisted through physical effort. Pulley systems above deck allow livestock or mortal crew to provide their own energy to the boat, and a captain's wheel allows directing the wheels along with the sails as usual - or, well, close to usual.
It is a slow, steady process, but it is surprisingly functional, and any with access to horses or similar beasts may easily attach them via leather harnesses to the front of the barge and allow them to pull the carónnae along.
Bumps in the road are dealt with by the shock absorption built into the wheels, though obviously, only small bumps can be tolerated. Carónnae are advised to be used on smooth roads as much as possible to avoid significant issues, much like how barges are advised to stick to rivers that have smoother currents and less narrow sections.

Prototype Carónnea by Hanhula (via Midjourney)

Nickname

Landboats

Manufacturer

Cravillaret

Creation Date

5587

Price

8000

Rarity

Uncommon

Width

20ft (6m)

Length

60 - 90ft (18 - 28m)

Speed

>12 knots on water; ~6 on land (condition & load dependent)

Cargo & Passenger Capacity

~120 tons

Pricing

Part of the reason carónnae are so well-adopted is due to their price. A standard river barge of average - but still large - size is able to be commissioned from a boat-builder for around 6,000 gold; carónnae barges are a 2,000 gold increase. For many, the additional cost is worth investing due to the additional utility.
Other types of carónnae, such as keelboats, can be constructed, but may take far longer and will certainly be more expensive.
Smaller barges, like cut barges, can also be had for far less: some opt for a few cut carónnae over one standard carónnae, and use their existing vessels alongside these smaller boats. It's seen as a good compromise for emergencies, or for sending some on ahead via road.

There's got to be a way to make the propulsion of these far more consistent... Some form of engine, perhaps, like the trains use?

— inventor

Social Impact

Our routes should adjust for the rivers; this risks our relationships with all the land-traversing traders..!

— elder

Naturally, this new development in riverfaring technology has been a significant upset to years of tradition. Though the elders of the Arriusi see the benefit, each group has its own conflicts and concerns about the carónnae's use. Some believe that to travel the roads is to step away from Arriusi tradition and swear only to use the carónnae in emergencies; others believe their creation to be a sin against the river-spirits that are rumoured to bless the Arriusi in their travels and refuse to use them entirely. Thus, opinions stay utterly mixed, even within groups.

Boats on the Road?! by Hanhula (via Midjourney)

No one group is utterly united on their opinion of these strange new inventions, and as such, each fleet is generally mixed in their use. No group has forbidden their use; no group has mandated it.
Use among the non-Arriusi picked up immediately, however. As the vessels are not magically powered in their transformative properties, the technology is flexible enough to adapt to many styles of boat, in theory. News of the new style of boating has spread like wildfire throughout Valathe, and is beginning to prove attractive to boat-builders throughout the lands. Shipbuilders from overseas have begun to catch wind of the new invention; Hvalgora, one of the world's foremost naval powers, is already preparing to send researchers to the Vostene Republic in search of information.
Though too young to see much immediate development, the technology is currently being tested in ships of various style and size to see whether it could benefit sea-faring vessels as well as the much smaller river barges it was intended for. This isn't likely to work without the addition of magical enchantments to reduce the weight and strain, but prior to the carónnae, the only vessels able to be multipurpose like this were wholly magical creations.
The carónnae is one of the latest inventions in the current upsurge in invention across Istralar as a whole, owing to periods of peace and improved trade contacts between nations. Though two of the largest nations still clash, it is hoped that the carónnae proves to be another unifying piece that leads to further innovation and invention beyond the limits of national borders.
Perhaps foolish in their hopes, the Cravillaret also hope that by sharing their engineering prowess with the world, the world shall also take better notice of their people: the Arriusi rely on trade, and word spreading of their accomplishments would be a boon to their people.

Is it so foolish to want our societies to improve for good?

— Cravillaret inventor