1855–1872
Twenty-four arches, and no iron in them
It took seventeen years. The work was driven by Fr Joseph Grégoire, whom his chronicler calls the apostle of Vadakenkoulam, and the building was engineered by a Jesuit lay-brother named Joseph Bergenthal, whose office the Society's Roman register for 1872 gives in two words: Ædif. eccl., builder of the church. Between them they turned twenty-four arches that carry their own weight, in lime and palm-toddy mortar, without cement, without iron, and without one wooden beam holding anything up. Halfway through, in 1861, the bishop came again, and three thousand Christians were waiting for him on the road.
In English
"Fr Joseph Grégoire… Vadakencoulam. — COADJUTORS: Joseph Bergenthal, builder of the church… Vadakencoulam."
What this source establishes
The single best fact on this page, and it is documented in ROME: the Society's own 1872 catalogue lists Br Joseph Bergenthal as "Ædif. eccl." — builder of the church — at Vadakencoulam, in the very year it was blessed. He appears NOWHERE on the open web. He also sits under COADIVTORES with no "P." prefix, which confirms he was a lay brother, not a priest.