AN IMPROVEMENT OR IMPROVEMENTS UPON STEAM BOILERS
Year: 1833

page_text: HANCOCK'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL-COME, I, WALTER
HANCOCK, of Stratford, in the County of Essex, Engineer, 'send greeting.
WHEREAS His present Majesty King William the Fourth, by His Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Fifteenth day of January now
last past, did give and grant unto me, the 'said Walter Hancock, His especial
licence, full power, sole privilege and authority, that I, the said Walter
Hancock, my executors, administrators, and assigns, and such others as I, the
said Walter Hancock, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within England; Wales, and the Town of Berwick.
upon-Tweed, my Invention of "AN IMPROVEMENT OR IMPROVEMENTS UPON STEAM
BOILERS;" in which said Letters Patent there is contained a proviso, obliging
me, the said Walter Hancock, by an instrument in writing under my hand
and seal, particularly to describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, and to cause the same to be
inrolled in His said Majesty's High Court of Chancery within six calendar
months. next and immediately after the date of the said recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully
appear..
NOW KNOW YE, that in compliance with the said proviso, I, the said
Walter Hancock, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is described and ascertained
in manner. following, that is to say :-"

page_text: My improvement or improvements upon steam boilers is most applicable t
those steam boilers of my Invention for which former Letters Patent wer
granted to me by His late Majesty King George the Fourth, dated the Fourth
day of July, One thousand eight hundred and twenty-seven, and which boiler
are composed by combining together suitable numbers of narrow flat vessels
made of thin metal plates, soldered and rivetted together properly to contain
water and steam, the said vessels being placed side by side in parallel vertica
planes over the fire, or edgeways upwards, and a series of them being combined
and united together, so as to give free passage for the water and steam from
one to another, and leaving narrow spaces between the adjacent vertical flat
surfaces of the several vessels to serve as flues for the passage of the flame
heated air, or gas and smoke, which ascends from the fire, and which is thereby
caused to envelope the said narrow flat vessels on both sides of each vessel, in
order to communicate heat with rapidity to the water contained in them, and
thereby generate steam from the said water. And in my former Specification,
which was inrolled, in pursuance of the said former Letters Patent, in the Petty
Bag Office, on the Fourth day of January, One thousand eight hundred and
twenty-eight, the structure of such boilers is fully explained and represented in
a Drawing annexed to the said Specification. It is therein stated that the
object of the said Invention was to construct boilers for steam engines so as to
be equally efficacious with boilers préviously in use, but of much less bulk and
weight, in consequence of their exposing a greater extent of surface to the
action of the fire and heat than ordinary boilers occupying the same space;
and also my said boilers, containing but little water in proportion to the surface
exposed to the fire; would be of less weight in proportion to the quantity of
steam produced from them in a given time than the boilers previously
commonly used for supplying steam engines, wherefore my said boilers would
be rendered suitable for locomotive steam engines for propelling vessels and
carriages. And it is therein described that the flat sides of each of the narrow
flat vessels are to be retained at their required distance apart from each other
by a number of tying rivet pins inserted through both the two sides of each
vessel, and rivetted on the outsides in order to tye the said flat surfaces to
each other at as many suitable places as will enable them to resist the tendency
of the pressure of the contained water and steam to separate the said flat
surfaces and distend the said flat vessels. And it is also therein described
that the series of such flat vessels which are to be combined together side by
side in parallel vertical planes to form one boiler are to be united together by
two or three strong iron bolts inserted through the thicknesses of all the several
flat vessels which are to be united together, rings of iron being interposed

page_text: between every two adjacent vessels to keep them at the proper distances apart,
in order to leave spaces between their adjacent vertical surfaces for flues, and
other like rings (but perforated with holes) being inserted withinside of each
vessel to keep the flat sides thereof properly apart, the said bolts passing
through the apertures of the said rings (but not filling those apertures), and
nuts being screwed very tight on the ends of the said bolts until all the vessels
and interposed rings are compressed so closely together as to prevent any
escape of water or steam between the circumferences of the said rings
and the flat surfaces of the vessels with which they are in contact; but
the internal apertures of the said rings, and of corresponding holes cut through
the thin metal plates which compose the flat surfaces of the vessels, being
much larger than the said bolts which pass through the said apertures, pas-
sages are thereby left around the bolts for the water and steam to communicate
freely from one chamber to another throughout the series of combined chambers.
And whereas I have, since the date of the said Specification, constructed
several boilers of the aforesaid kind, and have used the same for supplying
steam to locomotive steam engines, which I have constructed for travelling on
common roads in the manner of coaches, and have found such boilers to
answer the purpose very well; but as the tying rivets, whereby the flat sides of
the vessels were tied together to resist the pressure of the steam as aforesaid,
were liable to become leaky in long use, I found it would be an improvement
to omit such tying rivets altogether, and in lieu thereof to have the surfaces
of the vessels raised into elevated bosses projecting externally beyond the flat
surfaces by preparing the plate nearly in the same manner as was described in
my former Specification for forming the depressions which were to receive the
heads of the tying rivets, except that the plate was raised in an opposite
direction so as to project outwards from the insides of the vessel. The whole
surface of each vessel being raised with such projecting bosses at small dis-
tances asunder, but without any rivet holes in the bosses for tying rivets,
and the prominent bosses on the surface of one vessel being applied
against those of the next adjacent vessels, sufficient space was left between
the vessels in the. intervals between their bosses to form the flue passages
for the flame, heated gas, and smoke from the fire to act in and give heat
to the adjacent surfaces of the vessels. The contact of the said bosses
kept the sides of the vessels at their proper distances asunder, notwithstand-
ing the tendency of the internal pressure of the contained steam and
water to distend the vessels and collapse the flue
intended to
This mode of dispensing with tying rivets answered
be left between them.
spaces
very well in copper boilers, but, not having convenient tools for embossing

page_text: iron plates in that manner, and being desirous of using iron for cheapness,
I made the vessels with flat surfaces and interposed bars of iron endways
upwards between the adjacent surfaces of the flat vessels, in order to keep open
the spaces intended for flues, and resist the distending tendency of the internal
pressure of the steam and water contained, in the several flat vessels, the
pressure within one vessel being counteracted by the pressure within the next
vessel, the said bars being applied with their edges in contact with the flat
surfaces of the adjacent vessels kept those surfaces at their intended distances
apart, and the said bars divided the flat spaces betwen the vessels into a
number of upright flues or channels, through which the flame, heated gas, and
smoke from the fire ascended, to give heat to the water contained in the
vessels. I have constructed many of my patent boilers with the last-mentioned
improvement during the last three years, and have made much use thereof in
the various steam coaches which I have built, and such boilers have performed
very well.
My present Invention relates to the same description of boiler as aforesaid
for locomotive engines, and consists partly in interposing hollow.metal tubes
containing water in lieu of the iron bars which I have interposed (as herein-
before stated) between the adjacent flat surfaces of the several vessels whereof
the boiler is composed, in order to keep those surfaces properly apart and
counteract the tendency of the contained steam and water to distend the vessels.
The said hollow tubes being placed parallel to each other, vertically, or end-
ways upwards, in the spaces between the flat surfaces of the vessels at suitable
distances apart from tube to tube, to leave proper vertical channels between
the several tubes for flue passages, in order that the flame, heated gas, and
smoke proceeding from the fire may, in ascending through those passages, give
heat to the water contained in the said tubes, as well as to the surfaces of the
chambers between which the tubes are interposed; all the several tubes which
are interposed between the same surfaces are united together into one series
by suitable branch tubes so as to make a free communication for water and
steam from the interior capacity of one tube to that, of another, and the said
series of tubes being likewise united by suitable branch tubes to the rings
which are interposed as above described between the vessels around the strong
bolts by which the several vessels are united, to form one boiler, the communi-
cation of steam and water is thereby kept up from the interior capacity of all
the tubes to that of the flat vessels. By means of these tubes the efficient
heating surface in my boiler is greatly enlarged.
And another part of my present Invention is to place the fire grate and fire-
place for the burning fuel, which I have hitherto placed immediately beneath

page_text: the said boiler, as described in my former Specification, as much removed
from beneath the boiler as the width of the grate and fireplace; in order that
a sufficient stock of fuel; to last whilst the locomotive engine travels one stage,
may be put into a close chamber situated immediately over the fire grate, so
that the fuel will sink down by its own weight into the fireplace to supply the
waste by combustion therein, the fireplace being bounded at the side nearest
to the lower part of the boiler, and being separated from the space immediately
under the boiler by a vertical grating formed of upright hollow tubes, through
which part of the waste steam discharged from the engines is blown, and the
fireplace being also bounded on the opposite side to the last-mentioned vertical
grating by another vertical grating with upright bars, through which, as well
as through the ordinary horizontal fire grate on which the burning fuel rests,
the current of air is blown into the fireplace for animating the fire, and the
current of flame, heated air, or gas, and smoke passes from the fireplace
through the opposite vertical grating of waste steam tubes into the space
beneath the boiler, and therein rises upwards in the upright flues between the
chambers and tubes aforesaid, but the close chamber before-mentioned imme-
diately over the fire which contains the stock of fuel being shut up at
top so as not to permit any outlet for the air which is blown into the fireplace,
the fire will not burn upwards, but will consume the fuel at the lower part of
the stock which is contained in the said close chamber, and the stock of fuel,
descending by its own weight, will keep the fire completely supplied therewith
as long as any is left. The space immediately beneath the boiler into which the
flame, heated air, and smoke passes as fast as it is blown by the current of air
through the vertical grating of waste steam tubes (which is the only exit from
the fireplace for that current) is bounded at the side opposite to the said grating
by an iron plate placed aslant in an oblique direction suitably for directing the
current upwards through the upright flues of the boiler. The remainder of
the waste steam discharged from the engines is conducted beneath the said
oblique plate, which is pierced with holes to admit the waste steam to pass
through and mix with the current of flame, heated air, and smoke, whereby
the waste steam preserves the said plate from burning away by the heat. In
like manner the other part of the said waste steam which is blown through the
tubes of the grating preserves the said grating from burning, and the waste steam
5 which has passed through those tubes is discharged into the flues of the boiler.
And another part of my present Invention is to enable the fire grate
whereon the burning fuel rests at the bottom of the fireplace, to be removed
or drawn out from the fireplace whenever the said grate becomes clogged,
and the air passage between its bars obstructed by vitrified ashes, called slag

page_text: or clinkers, another clean grate being put into its place as fast as the former
foul one is drawn out without any material disturbance of the fire or any cessa
tion of the action of the fire on the boiler, for which purpose the fire grate
is
to be fitted into the lower part of the fireplace in the manner of a sliding
drawer, with suitable racks and pinions or other mechanical power to draw it
out horizontally, the clean grate which is to be substituted being applied to
one end of the foul one, which is to be removed, in the same groove, and so
connected therewith that the foul grate, when drawn out beneath the burning
fuel, will draw the other clean grate after it into its place without greatly
disturbing the fuel, except that a sufficient opening must be left above the
grate at that side of the fireplace towards which it is to be drawn out, in
order that the foul grate may bring out with it as much of the lower part of
the mass of the burning fuel as is intermixed with the slag or clinkers.
And for the more complete explanation of my said Invention I have here-
unto annexed a Drawing which contains a representation of a steam boiler con-
structed according to my improvement or improvements, and which is suitable
for supplying a locomotive engine for travelling on common roads, in the
manner of a coach, or for travelling on railways. This steam boiler consists
of ten flat vessels marked B, B, placed edgeways upwards side by side in
parallel vertical planes, leaving narrow spaces between them for the ascent of
the flame, heated air, and smoke which proceeds from the fire. The several
vessels are made of thin metal plate joined by soldering or rivetting together so
as to be capable of retaining steam and water within them, and they are joiner
together by two strong tye bolts H, H, passing through all the vessels, iron rings
p, p, being interposed between every two vessels, and the bolts H passing
through all the rings, the interior apertures of which being larger than the
bolts, space is left around the bolts for the passage of the water and steam,
permitting the same to communicate freely from one vessel to the next. The
outer surfaces of the two outermost vessels are supported by stout iron plates
A, A, applied flat against them, and the whole boiler is tied together by three
strong bars R, R, applied across each end plate A, and the end of those bars
are united by six tye-bolts S, S, which hold the boiler together, in addition
to the two tye-bolts II, E. The tendency of the internal pressure to distend
the several vessels is restrained by upright iron partitions interposed between
the adjacent flat surfaces of the several vessels, so as to divide the spaces
between those vessels into a number of upright parallel passages or flues.
Thus far the boiler is the same as those which I have made under my said
former Patent, and used in my steam coaches.
Part of my present improvement is the use of hollow tubes 1, 1, for the said

page_text: partitions between the vessels, in lieu of the iron bars which I have hitherto used
for partitions, the said tubes 1, 1, being of an oblong square form in their trans-
verse section, made of iron welded in the manner of gun barrels. Nine such tubes
are placed parallel to each other in an upright direction between every two vessels,
all the nine being united by short lengths of small round tubing 2, 2, into one
series, having free communication from the interior capacity of one tube to
another, and they are likewise united to the rings p, p, as represented, so as to
establish a complete communication between the interior of all the vessels and the
interior of all the tubes at top for steam and at bottom for water. The short pieces
of round tubing 2, 2, are cut with screw threads at each end, right-handed threads
at one end, and left-handed threads at the other end; and those ends are
screwed very tight into holes which are perforated and suitably tapped into
the flat sides of the oblong square or flattened tubes 1, 1, and into the sides
of the rings p, p. The upright flattened tube 3, which extends from one of
the rings p, p, to the other is contracted or drawn in at each end to a round
form, and those round parts are tapped and screwed tight into the rings. The
short pieces of round tubing 2, 2, which form the junctions of the flattened
tubes 1, 1, are not so large as the spaces between the vessels, and therefore
they leave passages at each side of them for the flame, heated air, and smoke
to rise up through the upright channels formed between the upright flattened
tubes 1, 1. The joints may be secured by brazing if necessary, or, in lieu of
small round tubes 2 for the junctions, small flattened tubes may be used and
united to the upright flattened tubes 1, 1, by rivetting or brazing them toge-
ther. The upper and lower ends of the upright flattened tubes 1, 1, are
stopped close by welding, and the series of tubes being alike at both top and
bottom, may be placed either way upwards, and when worn thin at one end
they may be turned the other end upwards. By withdrawing the several tye-
bolts H and S, the several vessels B and the interposed series of tubes 1, 2, 3,
may be separated, and any which are worn may be taken out to be repaired
and replaced by others which have been repaired, or by new ones. These
interposed series of tubes 1 and 3, being united to the vessels B, B, by their
connections 2 and p, will receive water in the same manner as the vessels, and
by exposing a considerable extent of surface to the action of heat for generat-
ing steam in addition to the surfaces of the vessels, will augment and improve
the effect of my former boilers by the substitution of such series of tubes in
lieu of bars for partitions. D, D, is the fire grate on which the burning fuel
rests; 4 is the grating of vertical bars in front of the fireplace; and 5 the grating
of vertical waste steam pipes at the opposite side of the fireplace. The said
waste pipes 5 are all joined to a larger horizontal pipe 6, into which the

page_text: waste steam from one of the steam cylinders of the engine is discharged from
the eduction pipe of that cylinder, and the waste steam rises up through the
several upright waste tubes 5, which form the grating, thereby preventing them
from being overheated by the fire and flame which passes between them. The
waste steam issues out at the upper ends of the waste tubes 5 into the flues or
Spaces between the vessels, where it mixes with the heated gas and smoke. 7, 7,
is the chamber over the fireplace for containing fuel; and 8, the aperture at
top by which the fuel is introduced, being shut by a close cover or door, so as
to prevent any exit of 'the air which is blown into the fireplace through the
upright grating 4, that air being conveyed thereto through a close trunk or
ashpit passage 9, 9, formed of thin iron plate from a revolving fanner, like that
of a winnowing machine, turned by the engines. 10 is the sloping plate which
is placed immediately beneath the boiler to direct the heat upwards into the
flues thereof, after passing between the grating 5 of waste pipes. The plate 10
is perforated with holes, and the waste steam from the other engine being dis-
charged into the space 11 beneath it, to preserve the plate 10 from being over-
heated, and the waste steam rising through the holes mixes with the heated air
and smoke. 12 is a front door which opens to give access to the fire through
the vertical grating 4; and 18 a door at the bottom of the ash-pit to remove
the ashes which have fallen through the grate, or, when required, to let fall the
whole fire, by drawing away the grate D. 13 is the moveable fire grate herein-
before mentioned. It is lodged in the space at the bottom of the fireplace
between the two upright gratings 4 and 5, being supported by a frame 14,
which is fixed to the large waste pipe 6. The bars of the grate are all united
into one frame or grating, which may be cast in one piece. The grate is
rather longer than the fireplace, projecting at each end, and the outside bars
15 are toothed at their under sides in the manner of racks, to work in the
teeth of two pinions 16, which are fixed on one axis situated across the end
of the fireplace 'outside. By turning that áxis and pinions 16 with a winch
the fire grate is slided or nioved endways, so as to be withdrawn out of the
fireplace from beneath the burning fuel therein contained without materially
disturbing that fuel, a spare or duplicate fire grate, in a cold and clean state,
being previously applied at the end of that grate which has become foul by
being clogged with clinkers or slag, and the end or cross bar 13 of one grate
hooking or interlocking into that of the other, as shewn in the Figure, the
clean fresh grate is drawn into its place beneath the fire as fast as the foul
one is drawn out therefrom. This change of the fire grate may be made in
locomotive engines when they are travelling a long journey, as often as is
requisite to keep up the fire in the best condition for burning freely. The

page_text: clean grate may be taken up at the appointed stopping places, and the foul
grate left behind, or, in case it should be preferred to carry the spare grate
with the locomotive engine, it may be more convenient to change only one
half of the grate at a time, and change more frequently, for which purpose
the grate must be made in two lengths united end to end in the middle of the
fireplace, as shewn at 21, by hook joints, as before mentioned; and when one
half is taken out at one end of the fireplace, another half is introduced at the
other end. A plate (which may be perforated with holes) may be made to
answer the purpose of a fire grate, and will be lighter, the side racks 15 being
fixed thereto along each side. The ends of the fireplace and sides of the space
beneath the boiler, and also the chamber 7, must be made of iron plates, lined
with flat tiles or plastering of fire clay or fire bricks, where necessary, to pro-
tect the iron from heat.
Having now described my said Invention, I, the said Walter Hancock, do
hereby declare that my improvement or improvements in steam boilers consist
in the substitution, as herein-before described, of a series of hollow tubes con-
taining water and steam for the iron bars, which I have before interposed as
partitions between the flat vessels, whereof the boiler is composed, and in the
arrangement herein-before described of the fireplace, with a chamber over it
for containing fuel, and vertical grates at each side of the usual fire grate,
for the current of air to be blown through across the fire, and also the
improvement, herein-before described, of drawing out and removing from the
fireplace the fire grate, when foul, to change it for another clean grate.
In witness whereof, I, the said Thomas Hancock, have hereunto set my
hand and seal, this Fifteenth day of July, in the year of our Lord One
thousand eight hundred and thirty-three