Conversion of historical stone bridge to lifting bridge in the Hořín lock chamber.

The paper describes design and construction process of the unique reconstruction of the historical stone bridge at the lower head of the listed Hořín lock chamber at the confluence of the Vltava and Elbe rivers near Mělník. The original stone arch bridge from 1905 at the outlet of the lock had to be carefully dismantled and rebuilt into a lifting bridge with a vertical lift of 5 m. The goal was to preserve bridges original listed and preserved appearance and enable larger ships to pass under it. The design of reconstruction consisted of proposal of new substructure, new hidden steel superstructure, new hydraulic and mechanical parts and electronical controling system. The original appearence of the stone cladding had to be preserved, so new hidden truss steel kernel was inserted to form the support for the original stone cladding and concrete coupling shell. The stroke of the bridge is controlled electronically by hydraulic cylinders and a system of guides and restraints. The reconstruction of this unique bridge had been carrefully performed under surveilance of National Heritage Office. The project recieved the Czech Construction of the Year 2022 award. [ABSTRACT FROM AUTHOR]