IMPROVEMENTS IN WATER TUBE STEAM BOILERS
Year: 1871

page_text: LETTERS PATENT to John Watt, of Birkenhead, in the County of
Chester, Engineer, for the Invention of "IMPROVEMENTS IN WATER
TUBE STEAM BOILERS."
Sealed the 7th May 1872, and dated the 8th November 1871.
PROVISIONAL SPECIFICATION left by the said John Watt at the
Office of the Commissioners of Patents, with his Petition, on the
8th November 1871.
I, JOHN WATT, of Birkenhead, in the County of Chester, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN WATER TUBE STEAM BOILERS," to be as follows:-
My Invention relates to the construction of steam boilers of the water
tube class for land and marine purposes, and also to various modes of
fastening the tubes in the front and back tube plates, and consists,―
First. As means for providing an efficient, durable, well stayed, and
easily repaired steam boiler, in which the water shall circulate freely, I
arrange and combine the parts in the following manner:-A series of

page_text: Seventh. As an alternative for either the fifth or sixth modifications,
I form the end of each tube conical inwards, with the tube plate to
match. A ring is fitted inside each tube, and another at the end against
the tube plate, and these rings are connected by bolts.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Watt in the Great Seal Patent Office on the
8th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
WATT, of Birkenhead, in the County of Chester, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of November, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Watt, Her special license that I, tho
said John Watt, my executors, administrators, and assigns, or such
others as I, the said John Watt, 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 makc, 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 WATER TUBE STEAM
BOILERS," upon the condition, amongst others, that I, the said John
Watt, my executors or administrators, by an instrument in writing
under my, or their, or one of 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 John Watt, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by tho
following statement, reference being had to the accompanying two

page_text: ACEST
thereon, that is to say:-
My Invention relates to the construction of steam boilers of the water
tube class for land and marine purposes, and also to various modes of
fastening the tubes in the front and back tube plates, and consists,―
First. As means for providing an efficient, durable, well stayed, and
easily repaired steam boiler, in which the water shall circulate freely, I
arrange and combine the parts in the following manner:-A series of
inclined water tubes are placed over the fire-grate, with sufficient space
between them to allow the flames and heating gases to circulate freely.
These tubes are connected at their ends to two chambers in com-
munication with the steam space, which steam space may consist of a
cylindrical or other vessel. The outer plates of the chambers are formed
with doors to allow the ends of any of the tubes to be easily reached,
examined, and any one removed and another put in its place without
disturbing the others. The outer plates and the tube plates are stayed
by stay bolts, which pass through the former and screw into the latter.
When desired the doors are secured by the same stay bolts. Instead of
the stay bolts just described, a central bolt for each tube may be used.
These pass from the covers and take hold of the tube fastenings. It will
be obvious they serve the double purpose of staying the outer and the
inner tube plates and securing the covers.
Second. As means for tightly securing the ends of the tubes in the
front tube plate I enlarge the outer end of the aperture through which
a tube passes, and after each tube is in position I screw a ring with an
internal flange or projection a little less than the thickness of the tube
into it, and afterwards screw a second ring into the tube, such latter
having an external flange which overlaps the ring first above named
under this head.
Third. As an alternative for the above second part I form the end of
each tube with a collar or flange, or make the end of the tube conical.
I then screw a ring into the tube.plate; such ring fitting against the said
collar, flange, or conical end makes the joint good.
Fourth. As an alternative for either the above second or third part
I fit a gland against the collar, flange, or conical part on each tube
mentioned in the above third part, and secure such gland by bolts.

page_text: Sheet A, Fig. 1, is a longitudinal elevation, and Fig. 2 an end
elevation, the outer tube plate of one boiler being removed so as to
show the position of the tubes of a set of four boilers constructed in
accordance with the first part of my Invention, and arranged for use on
board ship. In these views like letters denote the same parts.
a are inclined water tubes in communication with steam receivers b;
c, fire-grate. The tubes a are here shown secured to front and back
inner tube plates, marked respectively d and d, in the manner illus-
trated by Fig. 9, Shect B, the said tubes may be fastened in any ordinary
manner. e, c', respectively front and back water chambers. f,f', front
and back outer tube plates. The outer and inner tube plates are in this
modification connected and strengthened by stay bolts g, which are
screwed through the outer tube plates into the inner tube plates; if
desired they may be screwed through the outer and inner tube plates,
and have their ends rivetted down. They also secure the tube doors
or covers h. The direction of the heating flames and gases is shown
by the arrows. The features of greatest moment under this first part of
my Invention are the water spaces at the ends of the tubes, the stay bolts
connecting the outer and inner tube plates, and the tube doors or covers.
Sheet A, Fig. 3, is a longitudinal section of a land boiler constructed
under the first part of my Invention, the ends of the tubes being
fastened in the manner illustrated by Figs. 9 and 10, and the tube

page_text: openings in the outer tube plate closed by plugs. Here a are the tubes;
b, steam receiver; c, fire-grate; d, d¹, respectively inner and outer tube
plates; e, e', front and back water chambers; ff, front and back
outer tube plates. The plates are connected by stay bolts 9, which are
screwed through the outer tube plates and into the inner tube plates.
Sheet A, Fig. 4, is an end elevation and Fig. 5 a longitudinal vertical
section of a stationary boiler, the tubes being secured by the fastening,
drawn to an enlarged scale in Fig. 5º, and a central bolt applied to stay
the inner and outer tube plates as well as secure the covers of the tube
doors. This modification is also under the first part of my Invention.
Here 1 are the tubes formed with collars, which rest against a recessed
part of the inner tube plates 2; 3, tube fastenings screwing into the
inner tube plate 2, and formed with arms and a central boss to receive
the central bolt 4, which is constructed with a collar 5; 6, outer tube
plates; 7, tube doors secured by the said central bolt and nut. When
the nut is screwed home the inner and outer tube plates are stayed, and
the tube doors or covers 7 firmly fastened in position; 8 are stay bolts
screwed through both tube plates, and rivetted down at the ends.
A modification of the mode of fastening the end of the tube delineated
by Fig. 5, and adapted for the back end of the tube, is shown by
Fig. 5. Here the back end of the tube is screwed, and the fastening
screws over that part and against the inner tube plate. The central bolt
and other parts are substantially the same as in Fig. 5*, and are marked
with the same letters of reference. The direction of the flames and
The features of greatest moment
heating gases are indicated by arrows.
in this modification are the water spaces at the ends of the tubes, the
central bolts serving to stay the inner and outer tube plates whilst
securing the tube doors or covers, and these in combination with the
stay bolts.
Sheet B. The second head of my Invention is illustrated by Fig. 6,
which is a longitudinal section of part of a tube and inner tube plate.
1 is the tube; 2, tube plate; 3, ring with internal flange screwed into
the tube plate; 4, flanged ring overlapping the ring 3, and screwing
into the tube 1. Although this modification is specially suitable for

page_text: The third head of my Invention is illustrated by Figs. 7 and 8, which
are views in longitudinal section cach of part of a tube and inner tubo
plate, and Fig. 9, which shows part of a tube and inner and outer
tube plates, the latter with cover / secured by stay bolts, as shewn in
Fig. 2.

page_text: cover 6. The door may be otherwise secured or attached. This form of
fastening is only suitable for the back ends of tubes.
The seventh head of my Invention is shown by longitudinal section,
Fig. 13. The tube 1 is tapered or reduced in size at its end, and it fits
into a corresponding opening in the tube plate 2; 3, ring fitting inside
the tube; 4, bow or ring fitting outside over the end of the tube 1 and
tube plate 2; 5, screwed bolt serving to draw 3 and 4 together, and to
bind the end of the tube 1 close against the tube plate 2. This is
suitable for one end of tubes only.
Having now described the nature of my. said Invention, and par-
ticularized the same by various modifications, I would have it understood
that I do not confine myself to the exact details described and shown, as
modifications may be made without departing from the leading features
of my Invention; neither do I confine my improvements in fastening the
ends of tubes to boilers constructed under the first part of my Invention,
as the several modes of fastening may be advantageously applied in other
kinds of water tube boilers. What I do claim is,-
First. Constructing water tube steam boilers when the tubes are
placed in a horizontal or inclined position, and left in free communi-
cation at both ends, with water spaces between inner and outer tube
plates, with stay bolts and tube doors, the stay bolts for connecting and
strengthening the said inner and outer tube plates, and the tubed doors
for allowing examination, removal, cleaning, and refitting of tubes,
substantially as described and illustrated.
Second. Constructing water tube steam boilers with tubes in a hori-
zontal or inclined position, and in free communication at both ends, with
water spaces between inner and outer tube plates, when the said inner
and outer tube plates are connected and strengthened by the same stay
bolts which fasten the doors or covers, whereby entrance is obtained for
removal, repairing, cleaning, and refitting of the tubes, substantially as
described and illustrated.
Third. Constructing water tube steam boilers with a central bolt for
each tube, such central bolts serving to connect and strengthen the inner
and outer tubes and secure the tube doors or covers, substantially as
described and illustrated by Figs. 4, 5, 5%, and 5° of the accompanying
Drawings.

page_text: Fourth. The several modes of fastening tubes in water tube steam
boilers, substantially as herein described and illustrated by Figs. 6, 7, 8,
9, 10, 11, 12, and 13 of the accompanying Drawings.
In witness whereof, I, the said John Watt, have hereunto set my
hand and seal, this Sixth day of May, in the year of our Lord
One thousand eight hundred and seventy-two.
In the presence of
J. T. KING,
Patent Agent,
Liverpool.
JOHN WATT. (L.S.)