Creation of the Indret foundry 1777 (≈ 1777)
Installation by Sartine to modernize naval artillery.
1781
Becoming a Royal Manufacture
Becoming a Royal Manufacture 1781 (≈ 1781)
Official status as Brest and Toulon.
1810
Introduction of the steam engine
Introduction of the steam engine 1810 (≈ 1810)
Gradually replaces the tidal mill.
1828
Decommissioning of drilling
Decommissioning of drilling 1828 (≈ 1828)
End of industrial use of the building.
1842
Transformation into a neogothic chapel
Transformation into a neogothic chapel 1842 (≈ 1842)
First of the genus in Loire-Inférieure.
21 novembre 2022
Historical monument classification
Historical monument classification 21 novembre 2022 (≈ 2022)
Total protection of the site and remains.
Aujourd'hui
Aujourd'hui
Aujourd'hui Aujourd'hui (≈ 2025)
Position de référence.
Heritage classified
In total, including the ground, the frame vault with its luminaires and the vaulted infrastructures exposed, the drill-chapel of the manufacture of Indret, rue de Lorient, as delimited on the plan annexed to the decree and shown in cadastre Parcel No 123 section AH: inscription by order of 21 November 2022
Key figures
Louis XVI - King of France
Sponsor of the naval reconstruction post-1763.
Antoine de Sartine - Minister of Marine
Founded the foundry of Indret in 1777.
Wilkinson (famille) - English metallurgist masters
Introduced modern forge techniques.
Origin and history
Indret is an iconic building for the industrialisation of Lower Loire. Originally, this site was home to a tidal mill supplying a drill plant (drilling plant for cannons), built in 1777 on the river island of Indret, owned by the Crown. This strategic choice met Louis XVI's desire to rebuild the French fleet after the Seven Years' War (1756-1763), modernising artillery production. Innovative casting and drilling techniques, imported by the Wilkinson (English metallurgist masters), were implemented, making Indret the first royal cannon factory in the region, alongside Brest and Toulon.
In 1810, the arrival of the steam engine made the tidal mill obsolete, resulting in the decommissioning of the drill in 1828. The building was converted into a neo-Gothic chapel in 1842, becoming the first building of this style in the Loire-Inférieure (now Loire-Atlantique). This chapel, desecrated in 1976, served as a place of worship for the workers and inhabitants of the industrial district. Archaeological excavations conducted between 1998 and 2002 revealed the remains of the tidal mill beneath the building, confirming its dual industrial and religious heritage.
The site, acquired by the City of Indre in 2001, has been listed as a historic monument since November 21, 2022. It embodies the transition from the pre-industrial era (hydraulic energy) to the industrial revolution (steam machine), while symbolizing the spiritual anchoring of working communities. Its hybrid architecture — industrial vaulted infrastructures and neo-gothic elements — makes it a unique testimony to the technological and social history of the Lower Loire.
The location of Indret, on an arm of the Loire, was strategic: it allowed to exploit the energy of the tides to operate the wheels with blades of the mill, while facilitating the transport of raw materials (metal, coal) by river. This site is part of a major metallurgical pole, alongside the forges of Basse-Indre (1822) and the rolling mills of Couëron (1861), illustrating the economic boom linked to the port of Nantes, the first port of France in the 18th century.
