IMPROVEMENTS IN STEAM AND OTHER VESSELS, AND IN STEAM ENGINES, STEAM BOILERS, AND PROPELLERS APPLICABLE THERETO, PARTS OF WHICH IMPROVEMENTS ARE ADAPTED FOR OTHER PURPOSES
Year: 1870

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills, of 35, South-
ampton Buildings, in the County of Middlesex, Patent Agent, for
the Invention of "IMPROVEMENTS IN STEAM AND OTHER VESSELS, AND
IN STEAM ENGINES, STEAM BOILERS, AND PROPELLERS APPLICABLE THERETO,
PARTS OF WHICH IMPROVEMENTS ARE ADAPTED FOR OTHER PURPOSES."—A
communication from abroad by James Montgomery, of Livingston,
Columbia County, New York, United States of America, Civil and
Mechanical Engineer.
Sealed the 2nd August 1870, and dated the 11th June 1870.
5
COMPLETE SPECIFICATION filed by the said Benjamin Joseph Barnard
Mills at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 11th June 1870, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
JOSEPH BARNARD MILLS, of 35, Southampton Buildings, in the County
of Middlesex, Patent Agent, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
STEAM AND OTHER VESSELS, AND IN STEAM ENGINES, STEAM BOILERS, AND PRO-

page_text: PELLERS APPLICABLE THERETO, PARTS OF WHICH IMPROVEMENTS ARE ADAPTED FOR
OTHER PURPOSES," and have petitioned Her Majesty to grant unto me, my
executors, administrators, and assigns, Her Royal Letters Patent for the
same, and have made solemn Declaration that it has been communicated
to me from abroad by James Montgomery, of Livingston, Columbia
County, New York, United States of America, Civil and Mechanical
Engineer.
NOW KNOW YE, that I, the said Benjamin Joseph Barnard Mills,
do hereby declare that the following Complete Specification, under my
hand and seal, fully describes and ascertains the nature of the said
Invention, and in what manner the same is to be performed, in and by
the following statement thereof, that is to say :-
The Invention relates, firstly, to various improvements in the con-
struction of the hulls of steam and other vessels.
1. The hull of the boat is designed to have iron frames (ribs) to which
the wooden planking is secured by flanges on the ribs, dovetail grooves
in the planks, and locking keys.
2. The cutwater of the hull is strengthened by an overlapping plate,
which is drawn over the hooding ends of the forward strakes by means
of straining bolts, which have bearings at the after ends of wedges which
tend to press the said strakes against the cutwater plate.
3. The hull has one or more longitudinal trunks or cavities parallel
to the keel affording channels for the backward passage of the water
displaced by the propeller or propellers, which are placed at the forward
part of the vessel.
4. The forward end of the trunk has a flaring form, in order to present
a less resistance to the water, and also to afford an enlarged space in
which the propeller may operate.
5. Provision is made for locking several boats together endways to
afford either an elastic or a rigid connection as convenience may dictate.
6. An adjustable ice shield is attached to the bow, and is capable of
being lowered into working position or of being taken on board as may
be desired.
The Invention relates, secondly, to the propeller.
1. The screw propeller has a peripheral cylinder, which has teeth or
hollows to receive the cogs of the driving pinion, whose shaft is above
the usual load water line.

page_text: 2. The screw propeller being driven by a force applied to its periphery
the shaft of the propeller does not penetrate the hull.
3. The bearings of the propeller are supported by braced and stayed
frames from the hull, and at the rear of the propeller rim are antifriction
rollers against which it will bear if displaced by collision.
The Invention relates, thirdly, to the engine. The engine is of the
"trunk" form. Steam is admitted to the trunk side of the piston,
where it bears at full pressure upon the annular surface of the latter.
Being cut off at part stroke it expands during the remainder of the
stroke, and being then allowed to escape to the other side of the piston
it acts expansively against the circular superficies thereof. The effective
force of this stroke, the down stroke in the illustration, is the force of the
steam on the upper surface, less that on the area of the annular surface
exposed to steam on the under side of the piston, plus the atmospheric
pressure on the area of the trunk. The part of the lower surface of the
piston equal to the sectional area of the interior of the trunk is open to
the air, and the pitman which at one end is coupled to the crank at the
other end is connected directly to the piston head.
The Invention relates, fourthly, to the boiler. The boiler may be
termed vertical, and comprises several features, some of them intrin-
sically new and others associated in novel combinations.
1. The upper water space is around the furnace and above the crown
plate, and communicates with the water space beneath by means of a
central trunk and a surrounding jacket.
2. The grate is of an annular form and surrounds a downcast flue
which extends around the central water trunk for a part of the length of
the latter, and is rotated by hand or by machine power.
3. The rotatory grate occupies an elevated position in the boiler, and
receives its fuel by a chute or chutes from a hopper above the boiler..
4. The heated gases from the elevated furnace after impinging upon
the lower surface of the crown plate pass down an annular flue space
around the central water trunk, thence occupy a chamber in which they
are distributed to the upper ends of the vertical flue pipes, which conduct
the gases to a lower chamber, from whence they pass to a flue which
envelopes the sides of the boiler, and which terminates at a chimney
over the steam dome.
5. The water in the boiler establishes a circulation in the central

page_text: and up the other. The direction of its circulation will depend upon
certain points of construction which may vary without interfering with
the general idea of the construction, still retaining certain or all of the
points of novelty, which will be specifically stated hereafter.
And in order that the Invention may be more clearly understood and
readily carried into effect I will proceed, aided by the accompanying
Drawings, more fully to describe the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a longitudinal central vertical section of the forward part
of the vessel showing the engine boiler, propeller, and ice shield or
propeller guard in position; Figure 2 is a section on a similar line
embracing the after part of the vessel; Figure 3 is a bow on view of the
vessel; Figure 4 is a bottom view of the forward part of the vessel;
Figure 5 is a bow on view of a modified form of vessel furnished with
two propeller screws on the same transverse plane; Figure 6 is a bottom
view of the forward part of a vessel furnished with two propellers in the
same transverse plane; Figure 7 is a sectional view of the propeller
wheel, the sectional line being vertical to the axis and passing through
each of the four blades; Figure 8 is a view of a portion of the propeller
rim showing one of the sunken cogs or depressions with which the
periphery of the wheel is furnished and into which the cogs of the
driving pinion are engaged; Figure 9 is a detached view of one of the
bearings of the propeller wheel and the stays by which it is supported in
position; Figure 10 is a sectional view through one of the couplings by
which boats are connected in line; Figure 11 is a top view of the said
coupling; Figure 12 shows two boats so connected with the rigid bars
raised so as to permit flexure in passing a bend in the channel; Figure 13
is a horizontal section showing the mode of attaching the planking to
the frames of the hull; Figure 14 is a horizontal section showing the cut-
water plate and the manner of securing it; Figure 15 is a vertical sectional
view of the steam engine; Figure 16 is a horizontal section on the
line y, y, Figure 15, looking downward; Figure 17 is a sectional view
through the valve and valve chamber showing the valve in another
position to that exhibited in Figure 15; Figure 18 is a sectional view
through a portion of the trunk and of the piston showing a modified
construction; Figure 19 is a view partly in elevation and partly in
section of the steam boiler.

page_text: The hull A of the ship has a flaring opening B at the bow (as shown
in Figures 1 and 4) for the reception of a propeller wheel C, which
delivers the water aft into a passage D, which forms a longitudinal
trunk along the centre line of the vessel, as shown in Figures 1, 2, and 3.
This passage terminates in a similar flaring opening E at the stern, in
which is the after rudder F. A rudder is also mounted at the bow.
This arrangement may be duplicated, two propellers C, C, being mounted
in parallel openings B, B, and discharging the water aft through parallel
openings D, D, as seen in Figures 5 and 6. The ribs or frames A¹ of
the vessel follow the general shape of the transverse sections, bowing
upwardly at the middle line of the ship over the place occupied by the
keel and keelson in ordinary vessels. The line of the midship bend is
shown in Figure 3. The iron frames A', A', shown in Figure 13 have
flanges on each edge which enter dovetail grooves in the planking of the
inner and outer skin A³, A³, of the ship. A is a key which is driven
into the groove of the plank, and while it forms a key on one side to
hold the plank to the frame A', it at the same time draws the plank so
that it fits tightly against the opposite flange. Figure 13 shows two
somewhat different forms of ribs A', as exhibited in cross section, but
they agree in the respect of having flanges which occupy dovetail or
under cut grooves in the planking, into which they are forced by keys
which hug the flanges on the opposite edges. The hooding end of the
strakes A³ of the planking (Figure 14) meet at the bow, where they are
embraced between the leaves A³ of the cutwater plate. A bolt Aº passes
transversely across the bows, and is secured on the outer edge by splay
rivetting; this is to prevent the leaves from gaping open from the
strakes. The principal fastenings of the cut water plate are a set of
bolts, one of which A³ is shown in Figure 14, passing from the front of
the cutwater to the after side of the wedge block A', where it is secured
by a nut A. These horizontal bolts occur at regular distances, their
heads showing on the vertical edge of the cutwater, and serving to
draw the wedges A' firmly against the inner surfaces of the strakes A*, A²,
which are thus closely gripped between the wedges A' and the leaves of
the plate A³.
Figures 10, 11, and 12, show the arrangement for locking two boats

page_text: One
or river channel (Fig. 12), and a rigid union at other times (Fig. 11).
B' is a coupling bar which is connected to one boat in which it has a
certain amount of longitudinal motion. The other end of the coupling
bar has an opening which is engaged by a coupling bolt B. On the shaft
of the bar B¹ is a spring which is contracted by a power which tends to
draw apart the floating sections, and thus confers a certain degree of
resiliency upon the coupling. B³, B³, are two bars hinged to one section
and formed for the occupancy of grooves or recesses in the adjacent
sections to form a rigid connection between the two. When a lateral
flexure of joint is required the free ends of the bars are raised. In lieu
of the hinged bars for keeping the boats in line I propose to use a wire
rope running along and through massive eye bolts screwed into the deck
on both sides of the same at or near the ends of the boat sections.
end of each rope is hooked to an eye bolt on one section, and the other
passes around a winch on the other boat section. The turning of the
winches bringing a strain upon the wire rope brings the sections into
perfect alignment, when the coupling bolt may be dropped into place if
the object be to couple the two. When it is necessary to pass a bend
one windlass (or both) is partly unwound, slackening the connection to
the required extent. G¹ is an ice shield or propeller guard hinged to the
bow of the vessel, and lowered into position when it is to be used. At
other times it may be hoisted over the bow. C is a propeller wheel
shown in position in Figures 1 and 3, in duplicate arrangement in
Figures 5 and 6, detached in Figure 7, and a part of its rim merely in
Figure 8. This wheel has 4, or it may have a larger or less number
of blades which extend between the hub C2 and the outer rim C³, to each
of which the projecting flanges of the blades are rivetted, as shown in
Figure 7. The rim C³ of the propeller is shown in section in Figure 8,
and has two relatively sharp edges c, c, and a thicker middle portion,
the latter having depressions or sunk cogs c¹ around its periphery for the
engagement of the leaves of the pinion O*, whereby the propeller wheel is
driven. The pinion C is on a shaft which is driven by the trunk engine
by steam from the boiler. The hub C3 of the propeller is sleeved within
a collar L, stayed by bars and braces L', L', from the hull of the vessel.
This arrangement is particularly shown at Figure 9; Figure 1 shows it
in position. Being suspended in its bearings the shaft of the propeller
does not penetrate the hull, and the upper part of the periphery is above
the usual load water line, so that the point of application of the power
thereto is within view. A space in the hull above the wheel allows the

page_text: raising of the latter when unshipped, so as to be clear of the water. For
war vessels the shaft of the propeller driving pinion may pass through
the hull of the vessel below the water line to avoid injury by shot or
shell, in which case it will pass through a stuffing box like that of the
ordinary propeller shaft. The engine under these circumstances will
also be low down in the hull for the sake of protection. The engine is
of the trunk form, and is shewn at Figures 15, 16, 17, 18, and 19. In
Figure 19 the engine is shewn as mounted on a bed plate attached to
the side of a vertical boiler. In Figures 15 and 16 the engine is shewn
as mounted on a standing base frame. To the cylinder M are attached
two valve chests O¹, O², containing valves N1, N2, which are operated
by a rod O³, or by any suitable mechanisms and control the ports
P, P, P', P³, P', in the manner hereafter explained. To the piston G
is attached a trunk or hollow piston rod H of large diameter working:
through a stuffing box S in the heads of the cylinder M, so that the
steam in the lower part of the cylinder will be confined to an annular
space s¹, having a working area on the piston, which for use with high
pressure steam may be equal to about rd the area of the upper
surface of the piston, which has a full circular superficies. For economy;
and reliability the piston G and hollow piston rod or trunk H may.
preferably be cast in one piece. The connecting rod or pitman I passes
within the trunk H, and is connected with the piston G either directly
to the central part thereof, as shewn in Figure 15, or through the
medium of a connecting bolt K and nuts k, k³, as shewn in Figure 18.,
Under the construction last described the bolt K, with the pitman I, may.
be readily removed from the piston by taking off the upper head &² of
the cylinder and unscrewing the nuts k, k¹. If preferred the centre g of.
the piston may be made separately from the outer portion, the two parts
going together with an oblique joint, and being secured by tap or other
bolts J, Figure 15. This Figure also illustrates my mode of fitting the
piston to the cylinder either in the original construction of the parts or.
when the piston has become loose by wear. The periphery is either
originally cast or subsequently turned into the conical form represented,
and a case hardened ring g¹ is fitted thereto and tightened by means of
bolts j.
This ring may be cut obliquely in a common manner, and the
cut (g, Figure 16,) filled with metal wedged into it, a thicker plug or
wooden wedge being substituted when a further expansion becomes
necessary. Qrepresents a hollow metallic shield constructed preferably
in two parts attached to the stuffing box S, so as to be removable

page_text: therewith, and employed to cover the piston rod H, and to prevent its
surface from becoming coated with dust or cooled by currents of air.
This shield is of especial value in the application of the Invention to
locomotive engines. To prevent radiation of heat and consequent con-
densation of steam the interior of the trunk H is lined, and the exterior 5
of the shield Q wrapped with felt or other suitable material, and a soft
rope of spun yarn or some other loose packing is applied between the
trunk and the shield in order to prevent the circulation of air between
In Figure 15 the piston is represented at about half stroke, the steam
admitted from the boiler through the ports P, P¹, into the annular
space ¹ having been cut off so as to work expansively in the said
annular space. The steam in the space 83 at the upper end of the
cylinder is now exhausting through ports P³, P'; as soon as the forward
movement of the piston is completed the valve N¹ moves far enough
to throw the port P¹ into communication with the port P2, admitting
the high-pressure steam within the annular space s¹ to the steam chest 0°,
the boiler steam in the steam chest O¹ being still cut off from the
cylinder. This position of the valve is shewn in Figure 17. At this
juncture the valve N2 while still covering the exhaust port P*, uncovers
the port Ps, throwing it into communication with the steam chest O³, so
that the steam in the annular space s¹ and steam chest O³ is now allowed
to flow into the space 83 above the piston. The area of the circular
superficies on the upper face of the piston being much greater than that
of the annular surface on the under side of the piston causes the latter to
descend. The pressure of steam in the spaces s¹, s³, is equal during the
return stroke (downward in this position of the cylinder and piston); the
effective force exerted upon the upper surface of the piston will be due to
the fact that only atmospheric pressure is exerted upon a central portion
of the piston which is equal in area to the cross section of the hollow
trunk H. The return stroke of the piston being completed, the valves
are moved back so as to completely close the steam chest O², open the
port P¹ to the steam at boiler pressure within the steam chest O¹, and
connect the port P³ with the exhaust port P'. The forward stroke is
then produced by the pressure of steam within the space s¹ acting on the
annular working face of the bottom side of the piston, as already explained.
The attenuated steam in the space & has now almost entirely lost its ex-

page_text: pansive force, but its remaining heat may be utilized by exhausting it
into a tank or other receptacle or conductor of feed water. This engine
is applicable to locomotive, marine, manufacturing, and all other purposes
where motive power is required, and it may be arranged as an overhead
engine, as shewn in Figure 15, or mounted on its own plate or attached
to the side of a boiler, as in Figure 19, in which the vertical form of
boiler is exhibited. This is valuable for some locomotive purposes, and
especially for the class known as dummy engines," the necessity for a
skilled engineer to work the engine being entirely avoided, the supply of
fuel being automatic, and the starting, stopping, and reversing gear
being of the most simple character.
"
Among the advantages of the Invention the following may be
named:-
First. It allows a far greater expansion of steam in a single cylinder
than is attainable in any other of the usual methods; this is of especial
importance in marine engines where it is desirable to work the steam
expansively to its utmost limit.
Second. It requires far less steam than any other engine for the reason
stated, as a double stroke or one full revolution is made with one volume
of steam, and this volume being cut off short in the annular steam space
is worked by expansion successively at both ends of the cylinder. The
vertical steam boiler is shewn partly in elevation and partly in section
in Figure 19. R is an annular furnace surrounding a driving flue R',
and turning on balls or rollers beneath, it being moved by hand or
machinery as may be convenient. T is a coal chamber on top of the
boiler, and T is a chute, of which there may be several, reaching down-
ward for the supply of coal to the grate; T* is the apparatus by which coal
is admitted, and consists of a sliding gate moved by a hand wheel; T is
the usual furnace door; the diving flue R¹ is bounded by the back plate
of the annular furnace, and by a tube or trunk U which forms a central
connection between the upper water space U₁ and the lower water
space U; the diving flue R' leads to a wider space R* from whence it is
distributed to the flue tubes R³, it thence reaches the lower space R* and
then ascends in the flue space R³ which forms an envelope for the
boiler and leads to the chimney Rº. The lower water space U2 is partly
bounded above by the flue sheet V which slants upwardly towards the
outer part of the boiler so that the steam generated in this portion of
the boiler is directed outward to establish an upward outer current at

page_text: the parts U*, U*, the water again descending the trunk U so that a
circulation may be maintained; W is the steam dome.
Having thus described the nature of the said Invention, and the mode
in which the same may be carried into effect, I would have it understood
that what I claim is,―
First. The arrangement substantially as described of a screw propellor
in the bow occupying a flaring chamber which communicates by a
longitudinal trunk or cavity passing aft to the run of the vessel.
Second. A screw propellor constructed with a peripheral cylinder
which is supported at its rear by the hull of the vessel in case of 1
displacement by collision.
Third. A screw propellor whose cylindrical rim has teeth or hollows
to receive the leaves or teeth of a driving pinion.
Fourth. A screw propellor in which the rim is thinner at its edges.
Fifth. A screw propellor whose shaft does not penetrate the hull, 1
and which is driven by application of power above the water line.
Sixth. A screw propellor which is driven by a force applied to its
periphery.
Seventh. The described mode of connecting boats by elastic attach-
ment in combination with bars, by which rigidity is secured when 2
required.
Eighth. The adjustable ice shield hinged to the forward part of the
vessel and capable of being lowered into effective positon or raised on
board, as may be required.
Ninth. The mode of securing wooden planks or iron plates to the iron 2
ribs of vessels by flanges on the ribs, dovetail grooves in the planks, and
locking keys, substantially as set forth.
Tenth. The combination of the cutwater plates A³, wedges A', and
straining bolts A³, for strengthening the bows of a vessel, substantially
as set forth.
3
Eleventh. A steam engine constructed with a hollow piston rod
passing through one external head of the cylinder, and with double
valves so arranged that one body of steam may be cut off and worked
expansively within an annular space, and afterwards upon a surface of
larger arca on the opposite side of the piston, substantially as above set 3
forth.

page_text: Twelfth. In a steam engine constructed with a trunk or hollow piston
rod, the piston constructed substantially as herein described with means
for attaching the pitman removably to its central part and with a wedge-
shaped ring on its periphery for packing or tightening it within the
cylinder, in the manner explained.
Thirteenth. The combination of the pitman I with a removable part g
either attached to or constituting the centre of the piston G, substantially
as and for the purposes set forth.
Fourteenth. The combination of the double steam chests O', O³, and
valves N', N', arranged to operate substantially as described.
Fifteenth. The shield Q, applied substantially as and for the purposes
set forth.
Sixteenth. A boiler combining the following elements:-A central
water trunk, a concentric flue space around it, an annular grate around
the flue substantially as described.
Seventeenth. The rotating grate arranged in the upper portion of the
generator.
Eighteenth. The combination of the combustion chamber R, the
diving flue R¹, and the chamber R in which the calorified gases, &c.
are distributed to the flue tubes.
Nineteenth. A steam generator having the following elements in
combination :-A reservoir for coal around its upper end, a chute or
chutes for conducting coal to the grate, a rotating grate, and a chamber
above and one below the flue tubes substantially as described.
In witness whereof, I, the said Benjamin Joseph Barnard Mills,
have hereunto set my hand and seal, this Eleventh day of
June, in the year of our Lord One thousand eight hundred and
seventy