Science replaces guesswork
Before the mid-18th century, shipbuilding was an art, not a science. Shipwrights relied on tradition and jealously guarded trade secrets. They knew a certain hull shape worked, but they couldn't precisely explain why, nor could they reliably predict how a new design would perform without building the entire, expensive vessel. Naval architects operated "randomly and without a firm grounding," according to Henri-Louis Duhamel du Monceau, the Inspector General of the French Navy. This began to change here at the Toulon Arsenal, thanks to the application of early modern physics to naval engineering.
The intellectual groundwork was laid by mathematicians like Pierre Bouguer, whose 1746 "Traité du Navire" (Treatise of the Ship) established the core theories of ship stability and behavior. Duhamel du Monceau, a botanist and naval inspector, aimed to put these new theories into practice. In 1752, he published "Élémens de l'architecture navale" (Elements of Naval Architecture), a work that for the first time made the mathematical principles of shipbuilding accessible. To validate these principles, the calm, enclosed water of a dry dock at the Toulon Arsenal was repurposed into the world's first experimental test basin. Here, they conducted systematic tests on scaled wooden models of ships, a revolutionary approach to naval design.
From models to men-of-war
The experiments were simple in concept and deep in their implications. Small, precisely carved models of different hull designs were towed across the dry dock's surface at controlled speeds. By measuring the resistance each shape encountered, engineers could gather empirical data on their hydrodynamic properties. This allowed them to compare designs quantitatively and determine which forms were most efficient before committing vast resources to construction. It was the birth of predictive naval architecture.
This empirical method—testing physical miniatures to understand the behavior of full-scale machines—was an important moment for all of engineering. While the full development of hydrodynamic science would take another century, culminating in the sophisticated towing tanks of William Froude in the 1870s, the principles were established at Toulon. The knowledge gained here informed the design of French warships, which were highly regarded throughout the Age of Sail. The practice of using models to test and refine ship designs, born in a Toulon dry dock, is now a standard and indispensable step in the creation of every vessel, from cargo ships to nuclear submarines. The Musée National de la Marine, located at the arsenal's entrance, holds a collection of these enormous and detailed 18th-century ship models.