Transverse rib

A transverse rib (French: arc doubleau) is the term in architecture given to the rib of a rib vault which is carried across the nave, dividing the same into bays. Although as a rule it was sunk in the barrel vault of the thermae, it is found occasionally below it, as in the piscina at Baiae and the so-called Baths of Diana (Nymphaeum) at Nîmes. In the Romanesque and Gothic styles it becomes the principal feature of the vault, so much so that Scott^[1] termed it the "master rib".^[2]

References

1. Robert A. Scott, The Gothic Enterprise: A Guide to Understanding the Medieval Cathedral University of California Press (2003)
2. Chisholm 1911.

•  This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Transverse Rib". Encyclopædia Britannica. Vol. 27 (11th ed.). Cambridge University Press. p. 210.