Chainboats

Development and Adoption

Chainboats were initially invented by Le Choucas, an inventor in Balzana, in the Golden Sea. Based on his drawings, chainboats were first developed in Port De La Lune and used along the Sena River, opening the stretches known as the High and Little Sena to consistent navigation.
Chainboats are relatively new to Alvez, taking advantage of recent leaps in Tanfoeltr production and storage. Shallow-draught riverboats, their self-powered drives allow the craft to be pulled against the current on a long chain the length of its route, forgoing the need for draught animals and sails, and allowing for formerly nonnavigable rivers to be traversed.
Chainboats have led to a massive opening of previously inaccessible regions along interior rivers, leading to a development of industry, extraction of landlocked resources and the growth of interior settlements. They are cheaper and easier to operate than Windships, requiring neither Windspires or large bodies of water to take off and land. This has resulted in their widespread adoption by small and mid sized settlements in greater numbers, providing a much needed connection to established trade routes. Furthermore, their adopted use has led to an increased demand for tin and copper, as well as creating supporting industries forging the vast amounts of chain. Demand for Tanfoeltr and Ironglass has also increased as the chainboats are more widely adopted.
Chainboats are found across Alvez, but are especially common along the Sena River and its tributaries, the Goblin Canal from Gwened to Ker-Malastred and the Sona River in Liyon.

Design

Chainboats are symmetrical from bow to stern, with low profiles and shallow draughts to allow for shallow-river navigation while reducing the power needed to drag the ship along the chain. The bow and stern are almost level with the water, while the center of the vessel is slightly raised, giving the boat an almost triangular profile. The ships are typically made of oakwood and reinforced with bronze plating to protect the ships bow against impacts on the shallow riverbed or from floating debris.

Power Generation

The river chain, forged in bronze, carries no traces of the Hud, being magically inert. As a result, an external engine powered by Tanfoeltr, or liquid lightning, is required to move the wheels that pull the ship along the length of the chain. These engines are only slightly more powerful than draught animals, but require significantly less on-land infrastructure, allowing for more efficient travel against stronger currents and along uneven terrain.

Propulsion

Traveling downriver, chain boats largely rely on the current, sailing at the speed of the river as the waters carry it towards its destination.
Their true strength comes while traveling upstream, against the current. To accomplish this, a long bronze chain is sunken into the canal, anchored at each point of its route. The boat is then attached to this chain and fed through a series of wheels, rollers and drums to pull the ship along its length. The chain is raised out of the water at the bow, carried over the deck along rollers to a central drum apparatus, then lowered again by a winch at the stern. On larger vessels, some have began to add small water wheels on the sides of the vessel as well.
Every several hundred meters, the chains had links that could be removed, allowing ships to detach from the chain to allow other ships to pass or sideline a ship for rest or repair. If two boats met, a time consuming process involving the linking of auxilary chains is undertaken, allowing the vessels to pass each other.
The ship is steered by two rudders, one at each end of the vessel, as well as a series of swivellng booms to manipulated the chain around river bends. These powerful rudders compensate for the natural tendency of the chain to attempt to pull the ship straight along curves. The booms, extending over the bow and stern, raise the chain out of the wter to prevent it from striking or snagging on the gunwales. These booms are swiveled via hand cranks, allowing them to control the chain on riverbends and replace it in the center of the river after crossing.
Some chainboats, especially larger ones, are equipped with small sails to assist in chain free navigation, especially downriver.

Additional & auxiliary systems

The swivel booms are equipped with emergency interception equipment to catch the chain if it snaps. If these fail, the responsible chainboat crew must salvage the lost chain with a special drag anchor that is mandated on all ships making use of the chain.

Hangars & docked vessels

Due to the heavy spatial requirements of the lead boat, little cargo and only essential crew can be carried. Additional barges and Peniche are linked to the pilot boat and dragged along the river. A typical water train carries between 3 and 6 barges.

Nickname

Toueur, Le Choucas

Width

5 - 10 meters

Length

30 - 55 meters

Height

Draught (Unladen) ~ 40 cm/ Draught (Laden) ~ 75 cm