AN IMPROVEMENT CONNECTED WITH HEAVING UP SLIPS
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
We THOMAS SUMMERS and ARTHUR JAMES DAY both of the firm of Day,
Summers and Company Engineers and Shipbuilders, Northam Iron Works
Southampton in the Town and County of Southampton do hereby declare the
nature of our said invention for "AN IMPROVEMENT CONNECTED WITH HEAVING
UP SLIPS" to be as follows:-
Whereas in the ordinary method of constructing Slipways, the vessel to be
hauled up is carried by a cradle to which a number of wheels are bolted which run
on rails as in an ordinary railway or tramway. These wheels are fitted with axles
working in bearings so that the enormous weight of the vessel and cradle is really
carried by the said axles which rub against their bearings with great friction when
a vessel is being hauled up.
Now by our invention tho cradle and vessel are supported by rollers which
carry their weight but to which they are not bolted as in the case of the wheels of
the ordinary slipways. These rollers are kept at suitable distances apart from each
other by side frames and so dispense with the wheels and axles which cause so
much friction.
The cradle has rails bolted to its underside which rails rest on the top sides of
the rollers. The rollers themselves rest on rails similar to those ordinarily used
on slipways, and which are fastened to the groundways and foundations.
The great advantage of our invention is thus obtained by substituting rolling
for rubbing surfaces and we find in practice that the friction is 70° less with the
rollers than with the wheels and axles.

page_text: We THOMAS SUMMERS and ARTHUR JAMES DAY both of the firm of Day
Summers and Company Engineers and Shipbuilders, Northam Iron Works,
Southampton, do hereby declare the nature of our said invention for "AN IMPROVE-
MENT CONNECTED WITH HEAVING UP SLIPS," and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:
According to the ordinary method of constructing Slipways, the vessel to be
hauled up is carried by a cradle to which a number of wheels are attached which
wheels run on rails as in an ordinary railway or tramway. These wheels are fitted
with axles working in bearings, so that the weight of the vessel and cradle is really
carried by the said axles which rub against their bearings with great friction when
a vessel is being hauled up.
Now by our invention the cradle and vessel are supported by rollers, which
carry their weight, but to which they are not fixed as in the case of ordinary
slipways. These rollers are kept at suitable distances apart from each other by
side frames.
The cradle has rails bolted to its under side, which rails rest on the tops of the
rollers themselves. The rollers run on rails similar to those ordinarily used on
slipways, and which are fastened to the groundways and foundations.
The great advantage of our invention is thus obtained by substituting rolling
for rubbing surfaces thereby reducing the friction about 70 °.
The manner of arranging the rollers by our method will be clearly understood
by the annexed drawings in which at Figure 1 we show a vessel A on the cradle
or slip B, this having longitudinal timbers CC beneath the bilge portions where a
single set of rollres D D is fitted for each and with a double set of rollers EE
beneath the keel F on which rollers the cradle B can move when hauling up takes
place; the cradle being furnished with iron rails G to bear on the rollers D D and
E E as more clearly seen by the enlarged view Figure 2 which is a part
longitudinal elevation of sufficient of the slipway for explanation purposes.
The rollers D D and E E are held at their respective distances apart by side
links H H which are provided with fish plates I'I and with tie bars J J. The
rollers E E have a flange at each end as shown at Figure 3 as guides for the
parallel travel of the cradle B and also for their own parallel travel on the bearing
bars or rails K K, these being fixed upon the groundways L L forming part of the
foundation M.
Instead of making the rollers D D with one bearing surface on each only, said
rollers may have two bearing surfaces as shown at Figure 4 the outer end flanges
being dispensed with.
Any number of rollers can be arranged on the slipway and in the drawing
Figure 1 we have shown four sets while at Figure 5 we have two double sets as
illustrations only. In some cases the double rollers may be fitted at the keel
portion and single ones at the bilge portions.
It will be seen by the drawings that the rollers by our system are not fixed
except to the side links as frames for maintaining them at their respective distances
apart; and that friction is in consequence reduced to a minimum on account of a
rolling motion instead of a rubbing motion being obtained, an advantage of great
importance, because the power necessary for hauling up is considerably less than
that required under the ordinary methods of wheels and axles.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that
what we claim is :-
The arrangement of rollers hereinbefore described and substantially as shown in
the annexed drawings and their application between, yet independent of the cradle
and ground ways of heaving up slips as set forth.
LOL D1
100
H. GARDNER,
166, Fleet Street, London,
Agent for T. Summers & A. J. Day.