''MSM-1 USEL'' (Unità di Soccorso E Lavoro - Rescue and Work Vessel) was a

deep-submergence rescue vehicle A deep-submergence rescue vehicle (DSRV) is a type of deep-submergence vehicle used for rescue of personnel from disabled submarines and submersibles. While DSRV is the term most often used by the United States Navy, other nations have different ...

(DSRV) that was rated to dive up to . It was built by Cantieri Navali Ernesto Breda/

Fincantieri Fincantieri S.p.A. () is an Italian shipbuilding company based in Trieste, Italy. Already the largest shipbuilder in Europe, after the acquisition of Vard in 2013, Fincantieri group doubled in size to become the fourth largest in the world (2014 ...

for the

Marina Militare The Italian Navy (; abbreviated as MM) is one of the four branches of Italian Armed Forces and was formed in 1946 from what remained of the '' Regia Marina'' (Royal Navy) after World War II. , the Italian Navy had a strength of 30,923 active pe ...

. The sub was capable of descending to below the surface and could carry 8 passengers at a time in addition to her crew. ''MSM-1 USEL'' was hosted by

mother ship A mother ship, mothership or mother-ship is a large vehicle that leads, serves, or carries other smaller vehicles. A mother ship may be a maritime ship, aircraft, or spacecraft. Examples include bomber aircraft, bombers converted to carry exp ...

La Spezia La Spezia (, or ; ; , in the local ) is the capital city of the province of La Spezia and is located at the head of the Gulf of La Spezia in the southern part of the Liguria region of Italy. La Spezia is the second-largest city in the Liguria ...

from 1980 to 2002. That year ''MSM-1 USEL'' was replaced by the DRASS Galeazzi

SRV-300 SRV-300 is a deep-submergence rescue vehicle that is rated to dive up to . It was built by DRASS (Livorno) for the Marina Militare, and is capable of descending to carrying 12 passengers in addition to crew. ''SRV-300'' is hosted by ''Anteo'', ...

Characteristics

''MSM-1 USEL'' was the first submersible vehicle for underwater research and work of completely Italian conception. The basic design of ''MSM-1 USEL'' was done by ESCO of

Milan Milan ( , , ; ) is a city in northern Italy, regional capital of Lombardy, the largest city in Italy by urban area and the List of cities in Italy, second-most-populous city proper in Italy after Rome. The city proper has a population of nea ...

. The

pressure hull A submarine hull has two major components, the ''superstructure'' and the ''pressure hull''. The external portion of a submarine’s hull—that part that does not resist sea pressure and is free-flooding—is known as the “superstructure” i ...

is made of HY-80 steel and subdivided in two compartments: a cylinder with hemispherical ends located aft, and a sphere forward, interconnected by a cylindrical tunnel. The afterbody is tapered and finishes with the

propeller A propeller (often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working flu ...

cone. Aft stability planes, two vertical and two horizontal, are arranged forward of the propeller.

History

''MSM-1'' was updated (MLU - MidLife Update) in 1989 by MARITALIA of

Fiumicino Fiumicino () is a town and comune in the Metropolitan City of Rome, Lazio, central Italy, with a population of 80,500 (2019). It is known for being the site of Leonardo da Vinci–Fiumicino Airport, the busiest airport in Italy and the ninth-b ...

. Work took a year to complete and the vessel was renamed ''MSM-1S'' USEL. The DSRV's maximum depth was established near Cinqueterre (

) at .

Museum

Since 8 September 2015 ''MSM-1S USEL'' has been held by the Museo Tecnico Navale (Naval Technical Museum) of

and now is preserved for the public.

References

{{authority control Submarines of the Italian Navy Deep-submergence rescue vehicles Ships built in Venice 1980 ships Ships built by Fincantieri