Issue 50

A. Kakaliagos et alii, Frattura ed Integrità Strutturale, 50 (2019) 481-496; DOI: 10.3221/IGF-ESIS.50.40 481 Focused on the research activities of the Greek Society of Experimental Mechanics of Materials Damage and failure of Orban’s gun during the bombardment of Constantinople walls in 1453 Aristotle Kakaliagos Senior Structural Engineer, Greece nninis@culture.gr Nikolaos Ninis Civil Engineer, Greek Ministry of Culture and Sports, Athens, Greece nninis@culture.gr A BSTRACT . In this paper the bombardment of the Constantinople Theodosian Walls by the great cannon of Orban is numerically reproduced deploying Struc- tural Mechanics. Overall gun dimensions were assessed based on historical reports, whereby, the gunpowder charge p was estimated at 177 kg, and the gun was placed at 500 m from the Inner Walls. Gun ballistics and effect on target have been evaluated analytically. The analysis has verified Orban’s gun muzzle velocity, cannonball trajectory and its effect on Constantinople Walls by successfully calculating the length of the breach in the wall, referred in historical reports, as well as the cannon ball penetration into soil. The evaluated sound pressure level inside Constantinople, produced by the bombard, confirmed the tremendous psychological effect of the cannon’s blast on the City’s population. A numerical effort was made to assess the combined effect of powder chamber internal pressure with associate temperature produced by powder ignition. K EYWORDS . Bombard damage; Medieval gun ballistics. Citation: A. Kakaliagos, N. Ninis, Damage and failure of Orban’s gun during the bombard- ment of Constantinople walls in 1453, Frattura ed Integrità Strutturale, 50 (2019) 481-496. Received: 28.01.2019 Accepted: 29.05.2019 Published: 01.10.2019 Copyright: © 2019 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION t the dusk of the Late Medieval period, during the first half of the 15 th Century, Guns with enormous proportions appeared in the European battlefields. These guns manufactured by craftsmen originating from the traditional bell manufacturers in Europe were called Bombards. Manning and serving the Bombards was a difficult task, demanding excessive use of manpower, logistic and supply train, as well as skilled bombardiers who started rising from the ranks of craftsmen and combatants. Those heavy guns were mainly deployed during city sieges, hurling stone cannonballs of very large diameters. Rate of fire of those guns was slow and aiming on the target was also cumbersome requiring several trial shots to identify the successful cannonball trajectory. However, when used skillfully, the bombards could catapult stone cannonballs with enormous strike power on the enemy defenses. The bombards often carried names, demonstrative of their tremendous effect, in order to spray fear into the enemy ranks and press negotiations to surrender, well before A