A NEW OR IMPROVED METHOD FOR REDUCING THE FRICTION BETWEEN WATER AND SUBMERGED BODIES AND IN APPLIANCES CONNECTED THEREWITH
Year: 1882

page_text: LETTERS PATENT to Friedrich Hermann Felix Engel Civil Engineer and
Patent Agent in the City of Hamburg Germany for an Invention of "A NEW
OR IMPROVED METHOD FOR REDUCING THE FRICTION BETWEEN WATER AND
SUBMERGED BODIES AND IN APPLIANCES CONNECTED THEREWITH." A com-
munication to me by Gustaf de Laval, Doctor of. Philosophy of. Stockholm in
the Kingdom of Sweden.
PROVISIONAL SPECIFICATION left by the said Friedrich Hermann Felix
Engel at the Office of the Commissioners of Patents on the 7th December
1882.
FRIEDRICH HERMANN FELIX ENGEL Civil Engineer and Patent Agent in the
city of Hamburg Germany "A NEW OR IMPROVED METHOD FOR REDUCING THE
FRICTION BETWEEN WATER AND SUBMERGED BODIES AND IN APPLIANCES CONNECTED
"
THEREWITH a communication to me by Gustaf de Laval, Doctor of Philosophy of
Stockholm in the Kingdom of Sweden,
This Invention relates to a new or improved method for reducing the friction
between water and submerged bodies and in appliances connected therewith.
The main resistance and corresponding loss of working power in driving vessels
through the water is caused in the first part by the volume of water that has to be
displaced by the vessel during its progress through the water and in the other part
by the friction of the water caused against the submerged surface of the vessel.
It is to this latter part to which the present invention relates, that is to say, its
purpose is by an improved method and appliances connected therewith to reduce to
a certain extent the friction between water and submerged body and to attain a
higher rate of speed as well as to save coal and working power in driving such
vessels.
The resistance caused by friction increases with the speed of the vessel according
to formula
R. = c. a. v²
where c signifies the coefficient of friction, a the submerged surface and v speed of
vessel and the loss of working nower resulting from this is

page_text: In order to reduce R as well as A it will be desirable to make c as small as
possible and this is by the present invention attained by interposing between
submerged body and water a medium less adhesive than water. As the coefficient
of friction between atmospheric air or other gaseous substance is smaller than that
of water the real object of this invention is to introduce air or other gas between
water and a greater or smaller part of the submerged surface of a vessel.
This can be attained by attaching a system of chambers or tubes inside or outside
the bull of a vessel by forming such chambers or channels inside the sheeting or
walls of a vessel and by forcing during the progress of the vessel, air or other
gaseous substance into these chambers tubes or channels by means of force pumps
or other suitable arrangement and by allowing such air or gas to exit through
openings at the outer surface of the ships body. This air will partly form a
stratum between water and outer surface of the vessel and will in a corresponding
degree reduce the resistance of friction and the power required for driving such
vessel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Friedrich Hermann Felix Engel in the Great Seal Patent Office
on the 7th June 1883.
FRIEDRICH HERMANN FELIX ENGEL Civil Engineer and Patent Agent in the
city of Hamburg "A NEW OR IMPROVED METHOD FOR REDUCING THE FRICTION
BETWEEN WATER AND SUBMERGED "BODIES' a communication to him by Gustaf
de Laval Doctor of Philosophy of Stockholm in the kingdom of Sweden
"
This invention relates to a new or improved method for reducing the friction
between water and submerged bodies and in appliances connected therewith.
The main resistance and corresponding loss of working power in driving vessels
through the water is caused primarily by the volume of water that has to be
displaced by the vessel during its progress through the water and further more by
the friction of the water against the submerged surface of the vessel.
It is to this latter part to which the present invention relates that is to say its
purpose is by an improved method and appliances connected there with to reduce to
a certain extent the friction between water and submerged body and to attain a
higher rate of speed as well as to save coal and working power in driving such
vessels.
The resistance due to friction increases with the speed of the vessel according to
the following formula.
Rc. a.
where c signifies the coefficient of friction, a the submerged surface
and speed of vessel and the loss of working power resulting from this is
A=R. v=c. a. v³.
In order to reduce R as well as A it will be desirable to make c as small as
possible and this is by the present invention attained by interposing between
submerged body and water a medium less adhesive than water. As the coefficient
of friction between atmospheric air or other gaseous substance is smaller than that
of water, the real object of this invention is to introduce air or other gas between
water and a greater or smaller part of the submerged surface of a vessel.
This can be attained by attaching a system of chambers or tubes inside or
outside the hull of a vessel or by forming such chambers or channels inside the
sheathing or walls of a vessel and by forcing during the progress of the vessel, air
or other gaseous substances into these chambers tubes or channels by means of
force pumps or other suitable arrangement and by allowing such air or gas to have
exit through openings at the outer surface of the ships body. This air will partly
form a stratum between water and outer surface of the vessel and will in a corre-
sponding degree reduce the resistance of friction and the power required for driving
such vessel.
In the accompanying sheet of drawings is illustrated one mode of carrying out
this invention. a (Figs 1, 2 and 3) designates a system of tubes or channels
attached to the inner wall of the vessel. The air or other gas forced into this tube
system by pump or other pressure has exit against the surrounding water through
openings formed in the outer wall of the vessel as will be understood with reference
to Figs 1 and 2 of the drawings.
Fig 4 represents a chamber a¹ formed in front of the stem of a vessel into which
chamber air is forced by a pump or otherwise and from which the air escapes
through slits formed to the sides of the chamber.
As it is desirable to let the air escape with as low a pressure as possible to
overcome the outer pressure of the water it is especially with deep going vessels of
importance to divide the air tubes or chambers in upright direction into several
systems of which the lower systems receive a greater air pressure in consequence of

page_text: the greater column of water and air of different density is forced into the different
systems of tubes either by different force pumps or by other known mechanical
means.
Figs 5. 6, 7 and 8 represent the construction of a ship's bow furnished with the
new improvement in which air of different density or pressure contained in different
compartments kk k² (and.
1.so on five being shown) of an air-chamber R is forced
out at different heights of the ship's bow under line of water. The outlets i of the
air are divided by partitions & and each part is through a channel v in connection
with one of the compartments k k and so forth of the air chamber R in which
compartment air is contained of corresponding pressure which pressure must be
great enough to allow the air to escape against the surrounding water.
Having now described the nature and particulars of the said Invention in such
wise that the same may be readily carried into practical effect I claim:
11
Firstly. The application of upright.pneumatic chambers or channels to the inner
or outer wall, or within the wall of a vessel out of which chambers or channels.
through openings or slits air or other gas is forced out against the water for the
purpose of reducing friction between vessel and water.
Secondly. The mode of forcing air or other gas of different pressure out of such
openings or slits with a varying and rising pressure according to the depth of the
openings or slits below the water line.
+
Thirdly. The construction of the bow of a vessel with different compartments and
an, air chamber R, passages v and partitions das herein described and illustrated by
Figs 5, 6, 7 and 8 of the accompanying drawings..
04
In Witness whereof I the said Friedrich Hermann Felix Engel have hereunto
set my hand and seal this second day of June in the year of our Lord
One thousand eight hundred and eighty three.