Il progetto di reSTAURO della GRANDE gru idraulica dell’Arsenale di Venezia

Giulia Bettiol1, Alessandra Bovolenta2, Alberto Lionello3, Claudio Menichelli4

1Dipartimento di Costruzioni e Trasporti, Università degli Studi di Padova,

via F. Marzolo 9 - 35131 Padova, Italia,   giulia.bettiol@unipd.it

2Archittetto, v.le San Marco 69-30173 Venezia, Italia, alessandrabovolenta4.4@gmail.com

3Soprintendenza Belle Arti e Paesaggio di Venezia e Laguna,       

San Marco 1 - 30124 Venezia, Italia, alberto.lionello@beniculturali.it

4Architetto ex funzionario MiBACT, via Lago Vittoria 37/3 - 30034 Mira (VE), Italia,

arch.menichelli@gmail.com

ABSTRACT

The hydraulic crane in the Arsenale in Venice was made to order for the Italian Royal Navy by the British firm of Armstrong, Mitchell & Co. and came into service in 1885. Only nine examples of this type of crane were ever made and of these the one in Venice is the sole survivor.

Starting in 2007, thanks to finance provided by the British Committee for Venice, The Venice in Peril Fund, the Superintendency for Fine Arts and Landscape of Venice has carried out work to ensure the crane’s medium-term safety from collapse and has devised a full-scale restoration project.

The safety measures focused on the increasing fragility of the box containing the counterbalance ballast and the deterioration of the elements of the rotation system supporting the jib. The operations carried out involved reinforcement of the counter-balance box with textile straps and reduction of the volume and weight of the ballast from 400 to 300 tons.

As regards the restoration proper, the most complex operation will be the emptying and refilling of the counter-balance box. The project provides for an integrated system of adjustable tension cables, which will anchor the movable part of the crane structure to the ground, and of counterweights, which will enable the roller pads under the jib to be relieved of their load gradually and without altering the general balance of the crane. The project then envisages: the reinforcement of the hot riveting systems, the reconstitution and regrinding of the roller profiles and of the rotational drive pinion, the application of protective treatments to the metals, the reactivation of some of the movement mechanisms.

Parole chiave/Key-words:

Hydraulic crane, Arsenal of Venice, Armstrong Mitchell, restoration project