1.1.1 For the
purposes of these Rules, a water jet propulsion unit is described
as a machine which takes in water, by means of a suitable inlet and
conduit, and accelerates the mass of water using an impeller and nozzle
to form a jet propulsion system. The water jet system comprises the
unit and its associated actuation and control devices. The detail
of the prime mover is excluded but not its effect on the water jet
system.
1.1.2 This Chapter
defines the requirements for the design and service life of marine
water jet propulsion systems and is to be read in conjunction with
the General Requirements for the Design and Construction of Machinery
in Pt 12, Ch 1 Propellers.
1.1.3 The requirements
for a fixed or steerable water jet propulsion system rated at 500
kW and above, which is integral with the ship’s hull structure
and forms a means of main propulsion, are detailed in this Chapter.
This includes support arrangements, controls and the systems necessary
to maintain operation and functionality of the water jet unit.
1.1.4 These
requirements relate to water jets driven by axial or mixed flow pumps.
Where units driven by radial flow pumps or inducers are proposed,
details are to be submitted for consideration.