Year: 1896

page_text: I, The Honourable CHARLES ALGERNON PARSONS, of Heaton Works,
Newcastle-upon-Tyne, in the County of Northumberland, Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention relates to vessels propelled by steam turbines, and my object is to
obviate certain difficulties which I have experienced in applying steam turbines to
marine purposes.
I have found that when a steam turbine constructed according to any of my well
known types is applied to working a screw propeller directly, that the high speed
of the turbine necessitates a diameter of screw propeller which is rather too small
to provide sufficient blade area to absorb the power of the engine in propelling
the vessel with a high efficiency, and that sometimes under such conditions the
efficiency is reduced by the formation of vacuum behind the blades of the
propeller.
According to the present invention I diminish the work required from each
square foot of blade area and I secure a higher efficiency of the screw propeller or
propellers.
To obtain this better efficiency I arrange two or more screw propeller shafts to
each of which I couple a steam turbine which turbine may be complete in itself
and provide for the whole expansion of steam which is required or the different
turbines may be coupled by pipes and valves so as to cause the steam to pass
through them in series or in multiple series. By this arrangement the steam
passes from turbine to turbine and its expansion is completed in the series.
I thus divide the total power available among two or three or even more screw
propeller shafts and use two three or more motors instead of one. The notors so
arranged have distinct advantages as they are severally more rigid in construction
than the one large motor; they permit of greater refiuements of construction
and lower angular speeds may also be adopted without affecting the economical
consumption of the steam.
As regards the screw propellers their number and total blade area, their number
being increased the blade area is also increased and the work required from each
square foot of blade area is diminished so securing a higher efficiency as a screw
propeller.
Instead of coupling each turbine separately to a screw shaft I may connect,
couple or gear them in any way to each other or to the screw shafts. The
turbines I adopt may be of any known type but I prefer my well known turbines
with or without steam balancing arrangements for the screw thrust. The turbines
may be fitted with reversing gear if desired. Superheaters or steam driers in
the main steam pipe or in the connecting pipes between the motors may also
be used.
I may also fit between the motors suitable bye passes and valves to secure their
joint or independent working.
Dated this 21st day of May 1896.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents,

page_text: Improvements in Propelling Vessels by Steam Turbines.
I, The Honourable CHARLES ALGERNON PARSONS, of Heaton Works,
Newcastle-on-Tyne, in the County of Northumberland, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My invention relates to vessels propelled by steam turbines and my object is to
obviate certain difficulties which I have experienced in applying steam turbines to
marine purposes.
I have found that when a steam turbine constructed according to any of my well
known types, is applied to working a screw propeller directly that the high speed
of the turbine necessitates a diameter of screw propeller, which is rather too small
to provide sufficient blade area to absorb the power of the engine in propelling
the vessel with a high efficiency, and that sometimes under such condition
the efficiency is reduced by the formation of vacuum behind the blades of the
propeller.
According to the present invention I diminish the work required from each
square foot of blade area and I secure a higher efficiency of the screw propeller
or propellers.
To obtain this better efficiency I arrange two or more screw propeller shafts to
each of which I couple a steam turbine which turbine may be complete in itself,
and provide for the whole expansion of steam which is required, or the different
turbines may be coupled by pipes and valves so as to cause. the steam to pass
through them in series or in multiple series. By this arrangement the steam
passes from turbine to turbine and its expansion is completed in the series.
I thus divide the total power, available among two or three or even more screw
propeller shafts and use two, three or more motors instead of one. The motors so
arranged have distinct advantages as they are severally more rigid in construction
than the one large motor; they permit of greater refinements of construction and
lower angular speeds may also be adopted without affecting the economical
consumption of the steam.
As regards the screw propellers their number and total blade area, their number
being increased the blade area is also increased and the work required from each
square foot of blade area is diminished so securing a higher efficiency as a screw
propeller.
Instead of coupling each turbine separately to a screw shaft I may connect,
couple or gear them in any way to each other or to the screw shafts.
The turbines I adopt may be of any known type but I prefer my well known
turbines with or without steam balancing arrangements for the screw thrust. The
turbines may be fitted with reversing gear if desired. Superheaters or steam
driers in the main steam pipe or in the connecting pipes between the motors may
also be used.
I may also fit between the motors suitable bye passes and valves to secure their
joint or independent working.
Referring to the accompanying sheet of drawings illustrating one method of
carrying my invention into effect,
Figure 1 is a longitudinal section through part of a steam vessel showing my
turbine as applied to multiple propeller shafts, and
Figure 2 is the corresponding plan.
In this modification I use three turbines through which the steam passes in
series, the three turbines being coupled to three propeller shafts.

page_text: The high pressure steam is admitted to the high pressure turbine C' by the
steam inlet pipe 1. After passing through the turbine C' it is conducted by the
pipe D to the intermediate turbine C whence it passes to the low pressure
turbine C and then to the surface condenser by the large pipe F.
The turbine C is coupled to the propeller shaft A which shaft carries three
propellers B. The turbine C is coupled to the shaft A' which carries three
propellers B, and the turbine is coupled to the shaft A' which carries
three propellers B. The furnace forced draught fan E is also driven from the low
pressure turbine.
A reciprocating air pump G (Figure 1) is adopted for the condenser and it is
operated by the small reciprocating steam engine H.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is-
In propelling steam vessels by steam turbines the combination of two or more
turbines with two or more shafts carrying propellers substantially as herein set
forth.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.