IMPROVEMENTS IN NAVIGABLE VESSELS AND THEIR STEERING APPARATUS
Year: 1885

page_text: "
I, JOHN ISAAC THORNYCROFT, of Church Wharf Chiswick, in the County of
Middlesex, a member of the firm of John I. Thornycroft and Co, Steam Yacht
and Launch builders, do hereby declare the nature of said invention for
IMPROVEMENTS IN NAVIGABLE VESSELS AND THEIR STEERING APPARATUS' to be
as follows:-.
"
This invention relates to improvements in navigable vessels and their steering
apparatus and has for object to enable such vessels to be readily steered when
going either ahead or astern.
According to this invention the dead wood at the stern or propeller end of the
vessel is more or less cut away, the remaining portion being hollowed out to
partially receive the propeller or propellers.
At each side of the propeller is provided a rudder which may advantageously be
made of a form resembling in cross section a circular are, the rudder heads being
so arranged and supported that the rudders may be operated for steering purposes
without liability of their coming into contact with the propeller or propellers or
its or their carrying frame or frames. With the above described construction and
arrangement a vessel may be readily steered whether going ahead or astern, and it
will be understood that the propeller will be wholly immersed in water.although
the water line of the vessel may be below the top of the propeller blades.

page_text: .
I, JOHN ISAAC THORNYCROFT, of Church Wharf, Chiswick, in the County of
Middlesex, a member of the firm of John I. Thornycroft and Co, Steam Yacht and
Launch Builders, do hereby declare the nature of my invention for "IMPROVE-
MENTS IN NAVIGABLE VESSELS AND THEIR STEERING APPARATUS," and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :—
This invention relates to improvements in navigable vessels and their steering
apparatus and has for object to enable such vessels to be readily steered when
going either ahead or astern.
According to this invention the dead wood at the stern or propeller end of the
vessel is more or less cut away, the remaining portion being hollowed out to
partially receive the propeller or propellers. At each side of the propeller is
provided a rudder which may advantageously be made of a form resembling in
cross section a circular arc, the rudder heads being so arranged and supported that
the rudders may be operated for steering purposes without liability of their coming
into contact with the propeller or propellers or its or their carrying frame or frames.
With the above described construction and arrangement a vessel may be readily
steered whether going ahead or astern and it will be understood that the propeller
will be wholly immersed in water although the water line of the vessel may be
below the top of the propeller blades.
Referring to the accompanying drawings,
Fig. 1 shews in plan the stern portion of a vessel with my invention applied
to it.
Fig. 2 is a corresponding longitudinal vertical section.
Figs. 3 and 4 are to a larger scale, and shew respectively a side elevation partly
in section of a portion of the stern of the vessel with a rudder head and horizontal
sections at different points of a rudder blade, and a transverse section shewing the
form of the bottom of the vessel near the stern and the arrangement of the two
rudders between which the propeller or propellers (not shewn) is or are situate.
a is the hull of the vessel. b is the hollow portion intended to partially receive
the propeller c or propellers. d. d are rudders arranged one at each side of the
propeller or propellers. Each rudder as here shewn is of a form resembling in cross
section a circular arc (see Fig. 4).
Horizontal sections through the blade at various points in its length are shown
in the lower part of Fig. 3.
The dotted lines at the bottom of Fig. 3 indicate the shape of the plate that
forms the rudder before it has been bent to the arc-like form already mentioned.
In the arrangement illustrated each rudder head e. el extends upward through
a stuffing box f. f1, and at its upper part is provided with a toothed sector g, g' in
gear with a worm h. h¹ on a transverse shaft i operated by bevel gear k from the
shaft of the steering wheel . The bevel gear wheel on the shaft is arranged
°

page_text: to be thrown in and out of gear with the bevel gear wheel on the shaft i by
mounting the shaft'l so as to be capable of endwise movement in its bearings. Or
the shaft may be rotated for steering purposes by a chain m actuated by a
steering wheel or apparatus not shown. For this purpose the chain m is passed
through a fair lead or guide n and then round the chain wheel o on the shaft i
and back to the steering apparatus. When the chain m is used the bevel gear k
should be thrown out of gear. The rudders may however be operated in any
other convenient manner. They may be provided with curved portions at d* d*
having for object to deflect floating bodies that may strike these parts in order to
prevent such bodies becoming wedged between the rudders and the hull of the
vessel.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. A navigable vessel constructed with an external hollow or recess at the under
part of the stern to partly receive the propeller or propellers and having at each
side thereof a rudder arranged and operating substantially in the manner herein-
before described.
2. The construction and arrangement as hereinbefore described with reference
to and shewn in the drawings of a vessel in which the dead wood at the stern or
propeller end is cut away, the remaining portion being hollowed out to partially
receive the propeller or propellers, and two rudders with blades curved as set forth
are provided one being arranged at each side of the propeller or set of propellers and
the two rudders being connected in such manner as to operate, simultaneously as
specified.