urban water transport system is to be overhauled in the next decade as
the city's ageing fleet of 'vaporetti' is replaced by a new model of waterbus.
Designed to improve the performance of the city's passenger transport
system while reducing the risk of erosion by wave wash for Venice's historic
buildings, the new low impact water bus will form the basis of the fleet
of the future.
effects of so-called 'wave wash' - the waves generated by ships - on buildings
has been particularly felt in Venice. The city relies heavily on its fleet
of vaporetti as the principal means of public passenger transport on its
canal system and the adjacent lagoon. The principal objective of the LIUTO
(Low Impact Urban Transport Water Omnibus) project was the design of a
new hull form which would minimise this wave wash while maintaining or
improving the manoeuvrability and performance of the vessel itself.
under the 'Technologies for means of transport' sub-programme of the European
Commission's Industrial and Materials Technologies (BRITE/EURAM
3) programme in FP4, the LIUTO industrial research project consisted
of a collaborative venture between six partners from three European countries.
in canals and open water
vaporetti are managed by the local passenger transport company Azienda
Consorzio Trasporti Veneziano (ACTV), the LIUTO project's prime
contractor. ACTV is responsible for all public transport (road and
marine) in and around Venice.
identified its requirements for a new design of vessel in view of
two very different conditions in which they must operate:
1. In the narrow, shallow waters of the Venetian canal system;
2. In the open waters of the lagoon or 'lido'.
aim was to design a new model that would produce minimum wave wash
while achieving optimal performance in terms of energy efficiency
and manoeuvrability. As the degree of wave wash generation is principally
determined by the structure of the ship's hull, LIUTO set out to
redesign a new hull for the vaporetti using advanced technologies
developed for this purpose.
the hull design
basic hull form for the LIUTO waterbus was designed, developed and
refined by the Department
of Naval Architecture (D.I.N.) of the Frederico II University
in Naples, Italy. The objectives were to create a lightweight, stress-resistant
and low maintenance vessel with significantly reduced wave formation.
Several variations were sent to the Maritime
Research Institute Netherlands (MARIN) for optimisation using
MARIN's own RAPID
code, an advanced technology developed to measure wave generation
and wave impact.
LIUTO project permitted the extension, application and validation
of the latest tools for predicting and minimising wave wash. The
RAPID code was applied to several prototypes of the LIUTO waterbus
to determine the optimal hull form. MARIN tested the units in both
deep and shallow water, and at high and low speeds. The resulting
modifications to the LIUTO design resulted in a 30 % reduction
in wave generation at the ship's median speed.
S p A of Sarzana, Italy performed the material tests, designed
the structure and constructed the vessel prototype in highly resistant
composite material suited to the vessel's difficult operating conditions,
which include impacts, vandalism and exposure to solar radiation.
order to improve the manoeuvrability of the vessel and facilitate
docking, a new azimuthal propulsion system was constructed by German
marine propulsion specialist Schottel.
Two propellers suited to this propulsion system were studied and
built by the shipbuilding research institute Schiffbau-Versuchanstalt
Venice's water traffic legislation permits only two speeds - slow
in the canals and faster in open water - a parallel project was
initiated to design a hybrid diesel-electric system for the LIUTO.
The hybrid system, constructed by Italian company Ansaldo
Sistemi Industriali, is intended to optimise the boat's performance
at both speeds, permitting a switch from diesel when operating in
open waters to electric propulsion in the canals.
a fleet for the future
new LIUTO design will gradually replace the entire fleet of existing
vaporetti over a period of eight to ten years. The city of Venice
will benefit greatly in terms of preserving its historic buildings
while at the same time improving its urban passenger transport system.
The technology developed and perfected through the LIUTO project
is equally applicable in other European cities that rely on urban
water transport, such as Amsterdam and Lisbon.
is a major feature of the Land transport
and marine technologies key action. The LIUTO project developed
a new waterbus design that will reduce water-wash damage to Venice's
historical buildings and offers better performance in the city
canals and on open water.
- Low Impact Urban Transport Water Omnibus (BRPR960210)