Trezzo sull'Adda Bridge

Trezzo Bridge
Reconstructive drawing (surviving parts in dark grey) [1]
Coordinates	45°36′42″N9°31′20″E / 45.61167°N 9.52222°E / 45.61167; 9.52222
Carries	Two overlapped lanes for pedestrian, horses, carts, and wagons
Crosses	Adda River
Locale	Trezzo sull'Adda, Capriate San Gervasio
Characteristics
Design	Arch bridge
Material	Sandstone
Total length	72.25 metres (237.0 ft)
Width	9 metres (30 ft)
Height	20.7 metres (68 ft) intrados
Longest span	72.25 metres (237.0 ft)
History
Designer	unknown
Constructed by	Bernabò Visconti
Opened	1377
Closed	1416
Location

The Trezzo sull'Adda Bridge or Trezzo Bridge was a medieval bridge at Trezzo sull'Adda in Lombardy, Italy, spanning the Adda river. Completed in 1377, the single-arch bridge held the record for the largest span for over four hundred years, until the beginnings of the Industrial Age, ^{[2] [3] [4] [5]} while it was not until the early 20th century that masonry bridges with larger openings were constructed. ^[6]

History

The Trezzo Bridge was built between 1370 and 1377 by order of the lord of Milan Bernabò Visconti. ^[2] Fortified with towers, it provided access to the Visconti Castle high above the Adda. ^[2] During a siege in 1416, the condottiero Carmagnola deliberately caused the structure to collapse by weakening one of its abutments. ^[2]

Its single arch featured a span of 72 metres (236 ft), ^{[7] [3] [2] [4] [8]} according to other sources even as much as 76 m (249 ft). ^[9] By comparison, the second largest pre-industrial bridge vault, the French Pont de Vieille-Brioude, spans 45 m (148 ft). ^[2] The rise of the segmental arch was ca. 21 m (69 ft), with a span-to-rise ratio of 3.3:1. ^[2] The arch rip, measured at the springing, was 2.25 m (7.4 ft) thick, ^[2] corresponding to a favourable ratio of rib thickness to clear span of only 1/32. The sandstone bridge was almost 9 m (30 ft) wide. ^[2] Today, the two abutments with overhanging remnants of the arch vault are all that remain. ^[2]

The Trezzo Bridge was not matched until the metal Wearmouth Bridge of the same span was built at Sunderland, England, in 1796. ^[10] Longer masonry arch spans were not achieved until the 1903 Adolphe Bridge in Luxembourg. ^[6]

The Trezzo sull'Adda Bridge provided access to the Visconti Castle over the Adda. At the left-hand side, one abutment with remnants of the sharply rising arch vault is visible.

See also

• Pont de Vieille-Brioude (54 m span)
• Pont Grand (Tournon-sur-Rhône) (49.2 m span)
• Castelvecchio Bridge (48.7 m span)
• Pont du Diable (Céret) (45.45 m span)
• Nyons Bridge (40.53 m span)
• Puente de San Martín (Toledo) (40 m span)
• Ponte della Maddalena (37.8 m span)
• Pont del Diable (37.3 m span)
• Dyavolski most (13 m span)

References

1. Crivelli (1886), table 1.
2. Straub (1992), pp. 79f.
3. Hill (1984), p. 72.
4. Garrison (1999), p. 123.
5. Fernández Troyano (2003), p. 93.
6. Lay (1992), p. 268.
7. Degrand (1888), p.  72.
8. Fernández Troyano (2003), p. 116.
9. O'Connor (1993), p. 188.
10. Fernández Troyano (2003), p. 49.

Sources

• Crivelli, Ariberto (1886). Gli avanzi del castello di Trezzo – L'antico ed il nuovo ponte sull'Adda (in Italian). Milan: Prem. Tipo-Litografia degli Ingegneri. OCLC   878911168.
• Degrand, Ernest (1888). Ponts en maçonnerie. Volume 2 (in French). Paris: Baudry et C.ie, Libraires-Éditeurs. OCLC   313866610 . Retrieved April 23, 2025.
• Fernández Troyano, Leonardo (2003). Bridge Engineering. A Global Perspective. London: Thomas Telford Publishing. ISBN   9780727732156. OCLC   54805294.
• Garrison, Ervan G. (1999). A History of Engineering and Technology. Boca Raton, Florida: CRC Press. ISBN   9780849398100. OCLC   38474203.
• Hill, Donald (1984). A History of Engineering in Classical and Medieval Times. La Salle, Illinois: Routledge. ISBN   9780875484228. OCLC   10723141.
• Lay, Maxwell Gordon (1992). Ways of the World: A History of the World's Roads and of the Vehicles That Used Them. New Brunswick, New Jersey: Rutgers University Press. ISBN   9780813526911. OCLC   24010058.
• O'Connor, Colin (1993). Roman Bridges. Cambridge: Cambridge University Press. ISBN   9780521393263. OCLC   26543269.
• Straub, Hans (1992). Die Geschichte der Bauingenieurkunst. Ein Überblick von der Antike bis in die Neuzeit (in German). Basel: Birkhäuser Verlag. ISBN   9783764324414. OCLC   27082686.

External links

• Trezzo sull'Adda Bridge at Structurae
• Lombardia Beni Culturali – Ponte fortificato (ruderi), Trezzo sull'Adda (MI)