IMPROVEMENTS IN AND CONNECTED WITH MARINE AND OTHER STEAM ENGINES
Year: 1860

page_text: LETTERS PATENT to William Macnab, of Greenock, in the County of
Ronfrew, North Britain, Enginoer, for the Invention of "IMPROVEMENTS
IN AND CONNECTED WITH MARINE AND OTHER STEAM ENGINES,"
Sealed the 24th August 1860, and dated the 27th June 1860.
PROVISIONAL SPECIFICATION left by the said William Macnab at the
Office of the Commissioners of Patents, with his Petition, on the
27th June 1860.
I, WILLIAM MACNAB, of Greenock, in the County of Renfrew, North
Britain, Engineer, do hereby declare the nature of the said Invention of
"IMPROVEMENTS IN AND CONNECTED WITH MARINE AND OTHER STEAM ENGINES," to
be as follows, that is to say:-
This Invention relates to improvements in and connected with steam
engines, having principally for object the beneficial development of the
system of surface condensation in marine engines, but also in part applicable
to other engines.
The first part of the Invention relates to an improved general design of a
pair of engines of the "inverted-cylinder" class, with surface condenser,
suitable for driving the screw propeller. The surface condenser, in this case a
rectangular erection, having horizontal tubes arranged transversely in sections
for the passage through of the condensing water, is placed to one side of the
cylinders and midway between them longitudinally, being as close to them as
possible. There are two air pumps and two pumps for forcing the sea water
current through the condenser tubes, an air pump and a current pump being
placed on cach side of the condenser. The air pumps and current pumps are
[Price Sd

page_text: both single-acting, their buckets having trunks and acting vertically, being
worked by beains or levers actuated by the piston rod crossheads. One beam
or double lever on each side works both air pump and curreni pump. The
steam exhaust passages enter the condenser at the top, and the water of
condensation flows to the air pumps by troughs formed in the bottom of the
condenser. The air pump bucket does not rise to the top of the barrel or
cylinder, and a little water is in consequence always retained above it to keop
it tight whilst the discharge takes place into a well, which is open to the
atmosphere, and from which the feed pump takes the supply for the boiler.
Each current pump is placed outside of the respective air pump, and receives
the sea water through a valve arranged a little to either end or side, and so
as to be easy of access. The sea current enters the condensers by passages
from the pumps, entering at the outer side, and fitted with valves made
easy of access. Communications may be made to the condenser from the
donkey or auxiliary engine and pumps to admit of the condenser being
cleared or put into working condition independently of the main engines.
The second part of the Invention relates to an improved mode of securing
the tubes of surface condensers in their tube plates. A ring of clastic material,
such as vulcanised caoutchouc, is fitted tightly on the end of each tube,
outside the tube plate, and over this is passed a ferrule formed with an inner
flange or rim which covers or encloses the outer edge or end of the tube,
and with an outer flange, which bears on the elastic washer. These ferrules
or caps are secured to the tube plates by washers or holders screwed upon
studs or otherwise, provision being made for a little longitudinal movement
in the tube. Both ends of each tube may be secured in this way, or only
one end, and the other end may be held by a flanged ferrule fixed upon it,
and entering a hole of slightly increased bore in the tube plate, the ferrule
being secured in the same way as the modification previously described.
With these modes of securing the tubes they may be arranged very closely
without too much weakening the tube plates.
SPECIFICATION in pursuance of the conditions of the Letters l'atent, filed
by the said William Macnab in the Great Seal Patent Office on the
24th December 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MACNAB, of Greenock, in the County of Renfrew, North Britain, Engineer,
send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by ller Letters
Patent,bearing date the Twenty-seventh day of June, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Iler
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Macnab, Her special licence that I, the said William
Maenab, my executors, administrators, and assigns, or such others as I,
the said William Macnab, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
IMPROVEMENTS IN AND CONNECTED WITH MARINE AND OTHER STEAM ENGINES," upon
the condition (amongst others) that T, the said William Macnab, iny execu-
tors or administrators, by an instrument in writing under my,or their,orone ol
their hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Macuab, do hereby declare
the nature of my said Invention, and in what manner the same is to bu
perforined, to be particularly described and ascertained in and by the follow-
ing statement in writing, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say:-
My said Invention relates to improvements in and connected with steam
engines, having principally for object the beneficial development of the
system of surface condensation in marine engines, but also in part applicable
to other engines.
And in order that iny said Invention may be properly understood and
carried into effect, there is hereunto appended a Sheet of explanatory
Drawings, to which I shail refer in particularly describing my improvements,
premising that the same reference lettors mark the same or like parts in all
the Figures.
The first part of the Invention relates to an improved general design for
a pair of engines of the "inverted-cylinder" class, with surface condenser,
suitable for driving the screw propeller.
Figure 1, Sheet 1, of the Drawings is a transverse vertical section;
Figure 2 is a side elevation, one half in vertical section, as through one air
pump and part of the condenser; and Figure 3 is a plan, one half in hori-
zontal section, all representing a pair of engines as constructed according to

page_text: my improved design. The surface condenser is in this case a rectangular
erection A, represented in transverse vertical section in Figure 4, and in hori-
zontal section in Figure 5; it is provided with horizontal tubes B, arranged
transversely in sections, for the passage through of the condensing water,and
it is placed to one side of the cylinders C and midway between then longi
tudinally, being as close to then as possible. There are two air pumps D,
and two pumps E, for forcing the sea water current through the condenser
tubes B, an
air
pump D, and a current pump E, being placed on each side of
the condenser A. The air pumps D and current pumps E are both single-
acting, their buckets having trunks, and acting vertically, being worked by
beams or levers F, actuated by the piston rod, crossheads, or cross pins G.
One beam or double lever on each side works both air pumps D and
current pump E. Each lever F is also provided with pins h, i, for working
a feed pump H and bilge pump I. The valve casing J is as usual, between
the two cylinders C,and the steam exhaust passages K enter the condenser A
at the top. The water of condensation flows to the air pumps D by troughs L
formed in the bottom of the condenser. The air pump bucket d docs 1:ot rise
to the top of the barrel or cylinder,and a little water is in consequence always
retained above it to keep it tight whilst the discharge takes place into a
well M, which is open to the atmosphere, and from which the feed pump H
takes the supply for the boiler. Provision is shown for imparting additional
heat to the feed water prior to its entering the boilers, according to a plan
described in the Specification of Letters Patent granted to me, and bearing
date the 21st April 1860, (No. 1001.) The two feed pipes N are carried up
to a casing a, forming the top of the main condenser casing A, this smaller
casing a being provided with horizontal tubes b (by preference in sets, as
described in my earlier Specification just referred to), arrangedat rightangles
to the main condenser tubes B. The feed water is caused by directing
partitions in the end spaces to traverse these tubes backwards and for-
wards, for the purpose of taking up heat from the fresh entering steam,
which crosses the tubes on its way into the main condenser casing A. The
fool water passes on to the boiler by pipes connected to the casinga at n.
Each sea water current pump E is placed outside of or beyond the respective
air pump D, and receives the sea water through a pipe communicating with
the vessel's side. The sea water currents enter the condenser A from the
pumps E by passages P, in connection with which spaces are formed in the
pump casting to act as air vessels. Valves may be.applied in the passages P',
or immediately above the pumps E, as shown in Figure 1. The passages l'
communicate with spaces Q between the tube plates and covers of the con-

page_text: denser A, which spaces are separated by directing partitions, which cause
the currents to traverse successive sections of the tubes B in opposite direc-
tions, finally leaving the condenser by the outlets R. The condenser A is
further provided with a flanged duplex inlet S for sea water, and with an
outlet T for the water of condensation for the connection thereto of pipes
by means of which the donkey or auxiliary feed engine of the ship may be
made to act upon or clear out the condenser, and keep it in working con-
dition independently of the main engines. This arrangement may further
be taken advantage of to recover water otherwise lost (as blow-off steam,
for example,) when the main engines are not working.
The second part of my said Invention relates to an improved mode of
securing the tubes of surface condensers in their tube plates, which mode is
shown in Figures 6 and 7 on Sheet 2 of the accompanying Drawings, Figure 6
being an end elevation, and Figure 7 a longitudinal section, whilst several
tubes are shown with slightly modified examples of the securing details. A
ring or washer of elastic or compressible material, such as vulcanized caout-
chouc c, is fitted tightly on the end of each tube B, outside the tube plate e,
and over the projecting end of the tube there is passed a ferrule or ring con-
sisting of an outer flange f, which bears upon the caoutchouc washer e, and
(according to one modification) of an inner flange g (connected to the
flange by a short cylindrical portion), this inner flange or ring covering or
enclosing the outer edge or end of the tube B, but proportioned to admit of
the elongation of the tube 13 due to expansion, as shown at I, in Figure 7.
At 2 (Figures 6&7) a modification is shown in which the inner flanges y arc
dispensed with, the caoutchouc washers e being simply held down and com-
pressed by the flanges or washers . Both ends of cach tube B may be
secured in this way, or only one end, and the other may be held by a flanged
ferrule & fixed in the end of the tube B (or outside of it),as shown at 3(Figures
6 & 7). For the purpose of holding down the flanges (in the several
modifications), short screwed studs are fixed in the tube plates e, and upou
these are screwed nuts and washers, or flanged nuts r, in the manner shown in
the Figures; or instead of these, flanged or headed screws may be screwed
into holes tapped for them in the tube plates. In addition to what has been
described, it is preferred to apply beneath the caoutchouc washers c, a thin
slicet of caoutchouc t, or material of like properties, for the purpose of
protecting the external surface of the tube plate c. With these modes of
securing the condenser tubes, which are of course applicable with vertical
and other positions of the tubes, the latter may be arranged very closely
without too much weakening the tube plates.

page_text: Having thus particularly described ny said Invention, and the manner
in which the same is or may be used or carried into effect, I have to state
that do not restrict myself to the precise details herein-before described or
delineated, but that what I consider to be novel and original, and claim
as the Invention secured to me by the herein-before in part recited Letters
Patent, is,-
First, the arranging or combining together of the surface condenser, air
pumps, and current pumps, with the other parts of marine engines, sub-
tantially according to the design herein described and delineated.
Second, the securing of the tubes of surface condensers, and particularly
the holding of the securing washers or flanges by intermediate screws or
nuts, substantially as herein-before described.
In witness whereof, I, the said William Macnab, have hereunto set my
hand and scal, this Twenty-first day of December, in the year of
our Lord One thousand eight hundred and sixty.
Witness,
WILLIAM MACNAB. (S.)
EDMUND UNT, Patent Agent,
28, St. Enoch Square,
Glasgow.