Improvements in Balance Locks for Waterways.
Year: 1891

page_text: Date of Application, 11th Aug., 1891-Accepted, 17th Oct., 1891
QUMI LEIN DIDITATION.
Improvements in Balance Locks for Waterways.
I, CHAUNCEY NOBLE DUTTON; Engineer, residing at No. 5910 Rippey Street,
in the City of Pittsburgh, County of Allegheny, State of Pennsylvania, and
United States of America, 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 balance locks or elevators for raising and lowering
vessels from one to another level in waterways, and its object is to provide a lock
of any desired capacity which shall embody the advantages of capability of quick
operation, ready control, economy in the use of water, simplicity of construction,
low cost of construction and maintenance, and facility of repair when in operation.
The essential features of my invention constitute the elements of a balance, in
which there are substituted for the ordinary scale pans, two or more inverted tanks
containing a determined charge of air under pressure, and connected by valve
controlled conduits, to provide for the passage of air from one tank to another by
the manipulation of an operator, in the working of the lock. The charge of air
under pressure acts in the manner of the ordinary scale beam, and by variation of
its pressure within a lock, relatively to the weight thereof, the tank and the vessel
to be locked therein are caused to ascend or descend as the case may require. The
improvement claimed is hereinafter set forth.
The leading and characteristic features of my invention may be generally
described as follows. At any desired and convenient point in a canal or other
waterway, a retaining or head wall is built, dividing it into upper and lower levels.
Gates closing openings in the head wall retain the water in the upper level and
open to permit the passage of vessels therefrom into the locks. The lower level
of the waterway is expanded and deepened at and, for a distance from the head
wall somewhat greater than the length of the locks desired, to form a water well
for the reception of two or more air receptacles or tanks which are adapted to float
and move vertically in the water contained in the well. These tanks are closed at
top and open at bottom, and are charged with air under pressure, a determined
volume of which is divided between the several tanks and is retained therein by
the immersion of their lower walls in the water of the well serving to give them
the requisite buoyancy by expelling water from the interior of each tank.
The several tanks are connected by a system of pipes and valves, which control
the passage of air from one to another. Where two, four, or any other even
number of tanks is employed, each tank may be provided with an upper trough
or lock chamber, having openings controlled by gates, for the admission and
discharge of vessels to be locked or passed from one level of the waterway to the
other, and for retaining the vessels and the water in which they float, and these
lock chamber tanks are preferably, though not necessarily, arranged in pairs, the
members of each pair, with their valve controlled air connection, constituting a
complete balance lock system. In the use of one, three, or any other uneven
number of locks, one of the open bottomed tanks before mentioned is unprovided
with a lock chamber, and serves to balance the other tank or tanks, each of which
carries a gated trough or lock chamber. This balance tank is connected, by
independent valve controlled conduits, with the several lock chamber tanks, and
the construction provides a balance lock or a system of balance locks, as the case
may be.
In operation, a lock chamber tank is connected with one of the gated openings
in the head wall, a vessel is admitted from the upper level to the lock chamber, the
gates are closed, and the lock chamber tank is disconnected from the head wall

page_text: opening. At the same time a vessel is admitted to the lock chamber of the other
tank, if a pair of lock chamber tanks is employed, the water level in said chamber
corresponding with the lower level of the waterway, and the gates of the chamber
are closed. The vertical movements of the lock chamber tanks are so adjusted
that when any one of them stands at the lower level, its chamber contains a
minimum supply of water, as, for example, a depth of ten feet, and when con-
nected, at the upper level, to the gated opening of the head wall, its chamber
contains a imaximum supply of water, as, for example, a depth of ten feet, six
inches. The weight of the lock chamber tank which is at the upper level is thus
greater than that of the tank at the lower level to the extent of the weight of the
excess of water which it contains. These conditions are unaffected by the vessels
to be locked, as the weights of the latter are equivalent to those of the volumes
of water which they respectively displace. The weight of the elevated lock
chamber tank will therefore cause an excess of pressure to be exerted upon its
charge of compressed air, above that exerted on the air in the depressed tank.
Under such conditions, if the valves are opened, establishing communication
between the interiors of the elevated and depressed tanks, air will pass from the
former into the latter, and will cause the former to descend and the latter to
ascend, thereby reversing their relative positions.
In a system in which a balance tank unprovided with a lock chamber is employed,
the average pressure of the air contained. in the balance tank is constant, and
intermediate between the pressure in a lock chamber tank when elevated and when
depressed respectively, so that the lock chamber tank, when elevated and containing
its maximum charge of water, will. exert the greatest pressure and will force the
air into the balance tank, raising the latter and permitting the lock chamber tank
to descend, while the lock chamber tank, when depressed and containing its minimum
charge of water, will exert the least pressure, and the balance tank will force the
air into the depressed and lightened lock chamber tank and will raise it to the
upper level.
My invention is more fully exemplified and detailed in the accompanying
drawings, in which
Figure 1 is a plan or top view of a balance lock system embodying my
invention;
Fig. 2, a similar view, on an enlarged scale, of the lock chamber tanks and their
air connections;
Fig. 3, a transverse section through a pair of lock chamber tanks;
Fig. 4, a vertical longitudinal section through a lock chamber tank;
Fig. 5, a longitudinal section, and Fig. 6, an end elevation, showing one of the
pressure cylinders and pistons for ensuring close contact between the mouths of the
lock chambers and of the head wall openings;
Fig. 7, a sectional view, on an enlarged scale, through a lip and packing of a
head wall mouth;
Fig. 8, a view, partly in elevation and partly in section, of a flanged man hole
cover and valve; and,
Fig. 9, a transverse section through a balance tank and lock chamber tank.
In the practice of my invention, I locate my improved balance lock system at
any suitable point in the line of a water way, at which I construct a substantial
transverse retaining or head wall 3, which separates the upper level 1 of the
water way from the lower level 2. Channels or passages 4, of sufficient width
and depth to accommodate the largest vessels which are to be transferred from one
level to another, are formed in the head wall 3, said channels being provided with
gates 4" for retaining the water in the upper level at periods other than those when
vessels are being passed into and out of said level. The lower level is enlarged
and deepened at and adjacent to the head wall 3, to form a water well or pit 5, for
the reception of a series of floating lock chamber tanks A, either with or without
a balance tank B. The tanks are adapted to move vertically, without any sub-
stantial degree of longitudinal or transverse motion, in the water well 5, which is
:

page_text: preferably made with sloping sides and cemented, so that it may be scoured and
kept clean by a jet of water at high pressure.
The lock chamber tanks A are open bottomed chambers or casings 6, of steel
or other suitable material, and are of rectangular form and preferably of cellular
structure, that is to say, divided into a series of internal cells or compartments 7
by longitudinal and transverse vertical partitions 8. The adoption of a cellular
structure is desirable for the reasons that it strengthens the tanks, diminishes
liability to serious accident, and facilitates repairs when required. Several cells
might be perforated or otherwise injured without impairing the operativeness of
the lock, which, on the other hand, if the tank were undivided, would be liable to
be disabled by a single leak or perforation.
Н
Each of the cells 7 of the tanks 6 is provided with a manhole opening having
flanged nozzle or mouthpiece 9 closed by a cover 10, which is secured to make a
tight joint, with the capacity of ready detachment and replacement when required.
A suitable stop valve 11 controls an opening in each cell of the tank structure,
preferably in its manhole cover, and the outlet openings of said valves are
connected by pipes 12, controlled by valves 11", with a main pipe 13, controlled
by a valve 14, which is provided with a suitable detachable coupling 15, to admit
of being quickly connected with and disconnected from, a flexible pipe or hose 16,
by which the main pipes 13 of two lock chamber tanks are connected when said
tanks are to be balanced in a pair, or which serves to connect the interior of a
lock chamber tank with that of a balance tank B, when the latter is employed as
a balance in lieu of another lock chamber tank,
A lock chamber or trough 17, having its end openings or mouths 18 controlled
by gates 18, and of capacity sufficient to admit of the floatation of the largest
vessels which are to be transferred from one level to another, is formed upon the
top of each of the tanks 6. The ends of the mouths 18 adjacent to the head
wall 3 are adapted to be connected to those of the mouths 4 of said wall, so as to
make tight joints therewith with the capacity of ready connection and disconnection.
To this end, the mouths 4 of the head wall are extended outwardly therefrom by
throats 19, on the outer ends of which are formed laterally and downwardly
projecting lips or flanges 20. Corresponding inwardly and upwardly projecting lips
or Hanges 21 are formed on the outer ends of the adjacent mouths 18 of the tanks.
Either or both of the flanges 20 and 21 are provided with packing strips 22
(Fig. 7) of soft lead or copper. To ensure close contact of the flanges 20 and 21
and packing strips 22 when the mouths 18 and throats 19 are first connected, in
order to prevent leakage of water from the upper to the lower level, a series of
fluid pressure cylinders 24 is fixed to the walls of the lock chambers 17, adjacent
to the ends of their mouths 18 nearest the head wall. Each of the cylinders 24 is
fitted with a piston 23, the outer end of which is adapted to abut against the
flange 20 of the throat 19 of a head wall mouth 4, and to press the flanges 20
and 21 closely together. The pistons 23 are forced outwardly for this purpose by
air or water under pressure, which is admitted to the cylinders through pipes 25
controlled by valves 26, and are retracted by springs 27 to release the pressure
upon the flanges when the valves are adjusted to exhaust the actuating motive
fluid. It will be seen that hydrostatic pressure upon the lock chamber, when
opened to the water in the upper level, acts from the upper towards the lower level
or in the direction of the end of the lock chamber furthest from the head wall,
and thereby tends to increase the tightness of the joint between the mouths of the
head wall and lock chamber, by pressing their flanges closely upon the packing
strips. The gates which close the mouths of the head wall openings and lock
chambers may be of any suitable and preferred type, provided with the requisite
valves or wickets, and not forming, in and of themselves, any part of my present
invention, need not be herein at length described..
In order to prevent any substantial degree of lateral movement of the tanks 6,
as well as to properly limit their range of vertical movement, vertical guides and
stays 28 are provided. These are preferably cylinders, anchored at the bottom

page_text: A
and to the head wall 3 when adjacent thereto, and fitting freely in corresponding
lateral openings or passages in, the tanks 6. The end stops 28" of the stays 28 are
miade longitudinally adjustable by nuts 30 engaging threads on the stays.
further function of the stays is to admit of a restrained excess of bucyancy when a
lock chamber tank A is raised to its elevated position. At this period the lock
chamber contains its minimum charge of water and receives an accession, which
raises the charge to the maximum when the gates are opened to establisl
communication between the lock chamber and the upper level. In the absence of
an excess of buoyancy, such accession would cause the lock to descend somewhat
and abrade the packing of the joint between the mouths of the lock chamber and
head wall.
The provision of a man hole opening in each chamber or cell of the tank
enables repairs to be readily made when required in different portions of the lock
structure, without interfering with its operation. For this purpose a man hole
cover is removed' and an air lock fixed in its place. The cell is then filled with
compressed air and workmen are enabled to enter and make the repairs desired.
In this instance, the air pipes, connections, and valves are all exterior to the tank
and completely exposed, so as to be at all times accessible for renewal or repairs.
Such construction is desirable as attaining simplicity of structure and facility of
inspection and repair. It will, however, be obvious that any other preferred form
of controlled air connections would be fully applicable and operative and within
the scope and governing principle of my invention.
Inasmuch as the buoyant effect necessary to support a floating tank varies
relatively to its vertical position and the proportion of its structure which is
submerged, it becomes necessary to compensate for such variation as is induced in
and by the vertical movements of the tanks. To this end, equalizing devices are
provided, two forms of which are exemplified. That which is shown in Figs. 1
to 4, inclusive, consists in horizontal lateral extensions of the walls of the tank, at
such height thereon as to be normally below the surface of the water in which the
tank floats. Said lateral extensions form equalizing faces 31, the upper sides of
which are subject to the downward pressure of the superincumbent water, and
their under sides to the buoyant internal air pressure. The upward internal air
pressure being constant, or substantially so, and the downward water pressure
varying with the depth of immersion, it will be seen that by suitably proportioning
the parts, a practically perfect balance will be attained.
As shown in Fig. 9, the tanks are provided with side walls which converge from
the bottom towards, the top, so that both the upward pressure of the contained air
and the downward pressure of the exterior water are exerted upon surfaces the
horizontal projection of which varies with the degree of inmersion of the tank,
thus equalizing the buoyant effect of the charge of air and the downward effort
of the structure. The construction previously described is, however, deemed
preferable, for structural reasons.
The operation of a balance lock system in accordance with my invention is as
follows. Assuming, first, a balancing pair of lock chamber tanks to be employed.
One of the locks is elevated, and one of its mouths connected to the throat of tlic
adjacent mouth of the head wall, the head wall gates and the adjacent gates of the
lock chamber are opened, a vessel is passed into the lock chamber and the gates
are closed.
A vessel is at the same time admitted to the lock chamber of the
other tank, which is in depressed position, or at the lower level, and the gates of
this chamber are closed. The relative vertical positions of the lock chambers,
when elevated and depressed respectively, are so adjusted that the elevated
chamber contains a maximum quantity of water, and the depressed chamber, a
minimum quantity. That is to say, when the elevated and depressed lock chambers
communicate freely with the upper and lower levels, respectively, of the waterway,
the depth and volume of water in the lock chamber of the elevated tank exceed
the depth and volume of water in the lock chamber of the depressed tank. The
weight of the vessel or vessels in the chambers need not be considered being"

page_text: equal to that of the water displaced. The excess of water in the elevated lock
chamber will, therefore, effect an increase of pressure of the air contained in the
tank which carries said chamber, above the pressure in the depressed tank. The
elevated chamber is now detached from the head wall, and the valve or valves
opened which establish communication between the interiors of the two tanks,
whereupon the excess of pressure in the elevated tank, due to the greater weight of
water contained in its lock chamber, will cause compressed air to flow from the
elevated into the depressed tank, thereby raising the latter and permitting the
former to descend, thus reversing their relative positions. The excess of water
contained in the lock chamber which was originally elevated, is discharged
therefrom when its tank is depressed to the lower level. The motion of the
tanks is at all times completely under the control of the operator, who can
accelerate, retard, or suspend it at will by the manipulation of the valve
controlling the flow of air between the tanks.
When one or more lock chamber tanks A are used in connection with a balance
tank B, the operation is substantially similar to that above described, differing only
in the minor particular that the pressure in the balance tank averages an
intermediate between the maximum and minimum pressures in the lock chamber
tank. The employment of the balance tank B attains greater freedom of
operation than the disposition of lock chamber tanks in pairs, as the lock't
chamber tanks, when combined in pairs, necessarily move oppositely and syn-
chronously, while, when combined with a balance tank, they may be operated
independently, all ascending or all descending simultaneously, or one or more
ascending and one or more simultaneously descending, in any desired order or
relation.
It will be seen that the volume of water expended in transferring a vessel from
the upper to the lower level of a waterway, and (simultaneously in a pair of lock
chamber tanks, or at a subsequent period when a lock chamber tank and a balance
tank are employed), transferring another vessel from the lower to the upper level,
is only the comparatively slight excess of water contained in the elevated lock
chamber, and that, consequently, the quantity of water required for locking two
vessels is only a small fraction of that required for locking one vessel in the
ordinary practice.
It is desirable that an air compressing mechanism should be located conveniently
adjacent to the locks, for effecting the original compression of the buoyant charge
of the tanks at the installation of the apparatus, for supplying losses due to leakage
or other causes, and for use in connection with an air lock in making repairs.
Fig. 1 illustrates in general plan, upon a small scale, an apparatus proper for this
purpose, in which an air compressor 33 is actuated by a turbine wheel or other
suitable motor 32. The motor may also actuate a pump 34 for cleaning out the.
water well 5. Communication between the air compressor and pump and the tanks
and water well is established, when required, by detachable hose or connections.
Inasmuch as the necessity for the use of this apparatus is only occasional, and its
necessary operation comparatively small in degree, it may if desired, be made
portable and mounted upon a vessel or vehicle, so as to be transported from place
to place as desired in accordance with the requirements of its use. A single
apparatus may thus serve for all the lock systems of a canal or other waterway.
In addition to the normal balancing function of the balance tank when operating
in connection with a lock chamber tank, it may also be employed to equalize the
effect of changes of density in the adjacent atmosphere, .e. barometric and
thermometric changes. In certain conditions and with locks of certain proportions,
this latter function may become an important one, as the successful operation of the
lock tanks is dependent upon the displacement of determined volumes of water.
from their interiors. As is well known, the volume of any given quantity of air
varies with changes in temperature and barometric pressure, or in that atmospheric
density of which the barometric reading is the indication. The original charge of
air in the lock tanks will therefore tend to expel a greater or less volume of water

page_text: therefrom, in accordance with variations in atmospheric density as above mentioned,
and such a variation may be as great as five per cent. This variation is compensated
for by the balance tank B, which moves freely upwardly and downwardly,
maintaining a pressure upon its contained air which remains constant at a certain
degree above the atmosphere, however the density thereof may vary, The balance
tank consequently serves to perfectly equalize the atmospheric variation, as if the
atmospheric density or temperature should increase or decrease, and, as a result, the
lock chamber tanks should have too little or too great floatation, the opening of
the valves establishing communication will immediately effect an equalization and
restore the conditions of relative pressures requisite for the normal and successful
operation of the apparatus. When used merely for this purpose the balance
tank may be of small capacity relatively to the lock chamber tanks A, as say
about ten per cent. of their volume. A small equalizing balance tank B¹ is shown
in Fig. 1, in connection with a pair of lock chamber tanks, with which it is
connected by suitable flexible pipes or hose 16, controlled by valves 14. The
function of the balance tank in this connection being comparatively limited, it
may, if desired, he replaced by an air compressor or blower, which would constitute
its mechanical equivalent in its combination with a lock chamber tank.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In a balance lock apparatus, the combination of a floating and vertically
movable tank or casing adapted to contain a charge of compressed air, a gated lock
chamber fixed on said casing, a second floating and vertically movable tank or
casing adapted to contain a charge of compressed air, and a valve controlled air
passage connecting said tanks or casings, substantially as set forth.
2. In a balance lock apparatus, the combination of a floating and vertically
movable tank or casing adapted to contain a charge of compressed air, a gated lock
chamber fixed on said casing, a second floating and vertically movable tank or
casing adapted to contain a charge of compressed air, a gated lock chamber fixed
on said casing, and a valve controlled air passage connecting said tanks or casings,
substantially as set forth.
3. In a balance lock apparatus, the combination of a floating and vertically
movable balance tank or casing adapted to contain a charge of compressed air, two
or more floating and vertically movable lock chamber tanks or casings, each adapted
to contain a charge of compressed air and having a gated lock chamber fixed upon
it, and independent valve controlled air passages connecting the several lock
chamber casings with the balance casing, substantially as set forth.
4. In a balance lock apparatus, the combination of a head wall dividing a water-
way into upper and lower levels, a gated mouth or passage way formed in said
head wall, a tank or casing adapted to contain a charge of compressed air, said
casing floating and being vertically movable in the lower level of the waterway
adjacent to the head wall, a lock chamber fixed upon said casing and provided with
gated mouths or end openings, one of which is fitted to make a joint with the mouth
of the head wall, a second floating and vertically movable tank or casing adapted
to contain a charge of compressed air, and a valve controlled air passage connecting
said tanks or casings, substantially as set forth.
5. In a balance lock apparatus, the combination of a head wall dividing a water-
way into upper and lower levels, gated mouths or passage ways formed in said head
wall, one or more pairs of tanks or casings adapted to contain charges of compressed
air, said casings floating and being vertically movable in the lower level of the
waterway adjacent to the head wall, lock chambers fixed upon said casings, each
provided with gated mouths or end openings, one of which is fitted to make a
joint with a mouth of the head wall, and valve controlled air passages connecting
the casings of each pair, substantially as set forth.
6. In a balance lock apparatus, the combination of a head wall dividing a water-

page_text: way into upper and lower levels, gated mouths or passage ways formed in said head
wall, two or more lock chamber tanks or casings each adapted to contain a charge
of compressed air, and floating and being vertically movable in the lower level of
the waterway adjacent to the head wall, lock chambers fixed upon said casings, each
provided with gated mouths or end openings, one of which is fitted to make a joint
with a mouth of the head wall, a floating and vertically movable balance tank or
casing adapted to contain a charge of compressed air, and independent valve
controlled air passages connecting the several lock chamber casings with the
balance casing, substantially as set forth.
7. In a balance lock apparatus, the combination of a floating and vertically
movable tank or casing adapted to contain a charge of compressed air, a gated
lock chamber fixed on said casing, a second floating and vertically movable tank or
casing adapted to contain a charge of compressed air, a valve controlled air passage
connecting, said tanks or casings, an air compressing mechanism, and a detachable
valve controlled pipe or passage connecting said air compressing mechanism with
one of the casings, substantially as set forth.
8. In a balance lock apparatus, a ficating and vertically movable tank or casing
adapted to contain a charge of compressed air, said casing being provided with
outwardly projected walls increasing its lower width relatively to its upper width,.
in order to equalize the buoyant effect of the charge and downward effort of the
casing at different levels of Hoatation, substantially as set forth.
9. In a balance lock apparatus, a floating and vertically movable tank or casing
adapted to contain a charge of compressed air, said casing being provided with
horizontal outward extensions of its walls forming equalizing faces which are
normally located below the level of the water in which the casing floats, substantially
as set forth.
10. In a balance lock apparatus, the combination of a head wall dividing a
water way into upper and lower levels, a gated mouth or passage way formed in
said head wall, a tank or casing adapted to contain a charge of compressed air,
said casing floating and being vertically movable in the lower level of the water
way adjacent to the head wall, a lock chamber fixed upon said casing and provided
with gated mouths or end openings, one of which is fitted to make a joint with
the mouth of the head wall, and vertical guides entering recesses or guide openings
in the casing to prevent undue lateral or longitudinal movement thereof, substantially
as set forth.
11. In a balance lock apparatus, the combination of a head wall dividing a
waterway into upper and lower levels, a gated mouth or passage way formed in
said head wall, a tank or casing adapted to contain a charge of compressed air,
said casing floating and being vertically movable in the lower level of the water-
way adjacent to the head wall, a lock chamber fixed upon said casing and provided
with gated mouths or end openings, one of which is fitted to make a joint with the
mouth of the head wall, and vertical guides provided with end stops to prevent
undue vertical movement of the casing, substantially as set forth.
12. In a balance lock apparatus, the combination of a head wall dividing a
waterway into upper and lower levels, a gated mouth or passage way formed in
said head wall and provided with laterally and downwardly projecting flanges on
its end, a tank or casing adapted to contain a charge of compressed air, said casing
floating and being vertically movable in the lower level of the waterway adjacent
to the head wall, a lock chamber fixed upon said casing and provided with gated
mouths or openings, lips or flanges projecting from the end of the mouth of the
lock chamber adjacent to that of the head wall, parallel with and adjacent to those
of the head wall flanges, packing strips interposed between the head wall flanges
and lock chamber flanges, and mechanism for pressing said flanges closely against
said packing strips, substantially as set forth.
13. In a balance lock apparatus, the combination of a head wall dividing a water-
way into upper and lower levels, a gated mouth or passage way formed in said
Dead wall and provided with laterally and downwardly projecting flanges on its end,

page_text: a tank or casing adapted to contain a charge of compressed air, said casing floating
and being vertically movable in the lower level of the waterway adjacent to the
head wall, a lock chamber fixed upon said casing and provided with gated mouths
or openings, lips or flanges projecting from the end of the mouth of the lock
chamber adjacent to that of the head wall, parallel with and adjacent to those of
the head wall flanges, packing strips interposed between the head wall flanges and
lock chamber flanges, and fluid pressure cylinders provided with pistons by which
pressure is exerted upon said flanges for pressing them closely against said packing
strips, substantially as set forth.
14. In a balance lock apparatus, the combination of an open bottomed tank or
casing, internal partitions dividing the casing into a series of air tight cells or
compartments, and valve controlled air passages, each leading into one of said
compartments, substantially as set forth.
15. In a balance lock apparatus, the combination of an open bottomed tank or
casing, internal partitions dividing the casing into a series of air tight cells or
compartments, valve controlled air passages each leading into one of said compart-
ments, a main air pipe, valve controlled connections coupling the air passages of
the several compartments to said main air pipe, and a valve controlling said main
air pipe, substantially as set forth.
נים
Disl Da IT SA this 5th day of Luna A D 1891
Witnesses:
J. SNOWDEN BELL.
F. E. GAITHER."
CHAUNCEY N. DUTTON.