Improvements in or relating to the Lowering and Housing of Boats.
Year: 1893

page_text: Date of Application, 22nd Aug., 1893
Complete Specification Left, 15th June, 1894-Accepted, 28th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Lowering and Housing of Boats.
1, CHARLES DAVID DOXFORD, of Pallion Ship-yard, Sunderlaud, in the County
of Durham, Ship-builder, do hereby declare the nature of this invention to be as
follows:-
h
This invention relates to the lowering and housing of boats particularly on
vessels the following description serving to disclose the salient features of the
invention.
In this gear derricks are employed in place of the usual slewing davits; the
derricks may be formed of suitable section of iron or steel or wood with plate
beads, but preferably, I employ H section solid rolled steel bars, the central web
being cut away where required and the bars set to the required shape and pivotted
at their lower ends on suitable supports or upon any convenient place. In
" turret vessels they may be pivotted upon the stringer flange.
"
At the head of the derrick the centre web is cut away to accommodate the
necessary sheaves for the boat falls which are carried on a pin fitted through the
side cheeks of the derrick. A little below this the web is again cut away to
accommodate the roller guide for the guy rope; the centre web may be further cut
away at intervals where lightness is essential. Preferably two of these derricks
are used to each boat but if the boat be fitted with fore and aft sling suspension
gear one derrick only would be required. Any suitable deck bouse may be
utilized as supporting points for the derricks or suitable framing may be erected
for the purpose. At suitable positions upon the derricks iron supports may be
fitted to receive the boat chocks; these supports are preferably made to a V shape
with the apex horizontal and formed of plates fitted on either side of the derricks
and rivetted to the side webs thereof, the plates being bolted through with ferrules
on the bolts to maintain them at their proper distances apart. The upper arm of
the V receives one of the wood chocks and at the apex of the V a strong bolt is
fitted on which the outer chock bar is pivotted this bar being set to a convenient
shape to fit the bottom of the wood chock when the latter is made to fall. In the
lower arm of the V is fitted a suitable lever catch which by engaging the inner end
of the chock bar retains the outer chock in its working position; this lever catch
is preferably weighted at one end to retain it in engagement and is provided with
suitable stops to permit only the required amount of travel. A rope or chain may
be connected to the inner end of the chock bar for the purpose of pulling the
inner end down and therefore the outer end carrying the chock up after it has been
lowered for disengaging purposes; this rope or chain may pass through an opening
in the vertical portion of the derrick, safety hooks may be fitted where required to
retain the derricks in their vertical position, only one fall is used on each derrick
and this may be rove from the standing block attached in a suitable position about
the supports or deck house, to the block attached in the boat merely passing over the
sheaves in the head of the derricks. The usual hook or disengaging gear is fitted
in the boat for the attachment of the falls and is supplemented by another hook
secured to or forming part of the first hook or fitted independently in the boat' for
receiving the suspension hook presently to be described.
In the head of the derrick by preference on the sheave pin is fitted a suspension
rod having a suspension hook pivotted in its lower end and working between the
sides of the suspension bar which is formed at that part into a long eye; the
suspension rod may be provided at a convenient point with an eye on the side next
the boat fall the standing end of the fall being rove through the eye so that the
proper position of the rod with relation to the fall may be assured. On the sheave

page_text: pin are also fitted side links connected at their free ends by a cranked bolt the
crank being adapted to receive the eye of a guy rope for the purpose of maintaining
the derrick at a suitable point when lowered. This bolt also carries a weight so
that the links may hang down, except when the guy is tight which only occurs
when the derrick is lowered, a connecting chain rope or link is employed between the
weight and suspension hook. The derricks are connected by the usual span which
may be extended fore and aft and attached to suitable eye-plates in the line of the
pin on which the derricks are pivotted.
When the derricks are not so conveniently placed to sustain the weight of the
boat in chocks the latter may be fitted in the usual manner on suitable beams or
deck houses and the boat raised up to clear the chocks before the derrick is
lowered in this case two or more boats may be housed below the same derricks.
Where the boats are carried in chocks fitted on the derricks the operation of
lowering is as follows:-
•
The falls being held on a pin or winch end the safety hooks are cleared from the
derricks and the lever catches knocked back so as to allow the outer chocks to fall;
the boat is then freely lowered into the water the derricks carrying it clear of the
vessel's side. The boat is held in the suspension hook and the derrick falls
outwards with the boat until the guy tightens when the suspension hook is opened
and the boat lowers vertically into the water.
The raising of the boat is effected by simply hauling on the tackles the boat
rising vertically until it touches the suspension rod when the derrick rises and the
suspension hook is allowed to close and after the derrick has travelled almost home
it suspends the boat carrying it straight into the chocks when it is only necessary
to close the outer chock: by pulling down the inner arm until it is caught by the
lever hook, then replace the safety hook and the boat is housed requiring only to
have the ordinary grips replaced to make all secure.
With this arrangement one man at the falls and one to undo the chocks and
safety hooks is all that is required for lowering a boat into the water when if an
automatic disengaging gear is employed the boat will be free. The usual slewing
of davits is therefore entirely avoided together with the relatively large number
of men required to effect it and the time occupied in lowering a boat is reduced.
No screw or other gear is necessary for putting the derricks out as the weight of
the boat is utilized for this purpose and one tackle only. is used for both operations
of putting out the derrick and lowering the boat.
Dated this 18th day of August 1893.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
COMPLETE SPECIFICATION..
Improvements in or relating to the Lowering and Housing of Boats.
I, CHARLES DAVID DOXFORD, of Pallion Ship-yard, Sunderland, in the
County of Durham, Ship-builder, 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 :-
This invention relates to the lowering and housing of boats particularly on
vessels and will be best understood by reference to the accompanying drawings
in which
Figure 1 is an elevation showing the boat lowering and housing apparatus in two
of its positions.
Figure 2 is a side elevation of portion of the boat showing the manner of
attaching the falls to it and the arrangement of the chocks beneath it.
Figures 3 and 4 are detail views of one of the shackles by which the derrick.

page_text: spans are connected to the derricks and through which the boat is released from the
falls.
Figures 5, 6 and 7 are detail views showing the preferred means for locking and
pivotting the derricks.
Like letters represent like parts throughout the drawings.
A is a derrick or derrick bar one similar to which may be arranged near each
end of the boat B; only one is shown in the drawings, from which however the
arrangement of both will be readily understood. These derricks I prefer to form
of H-section solid rolled steel bars (though other material such as iron or wood may
be used in their construction) set to the required shape and pivotted at their lower
ends on suitable supports or upon any convenient place. In "turret" deck vessels
such as that to which my invention is shown applied in Figure 1 the derricks may
be pivotted upon the stringer flange, or, as indicated in that figure, in brackets C
rivetted or otherwise secured to the bulwark D. A convenient way of
"building up" the lower end of the derrick A so as to give it a substantial bearing
surface upon its pivot bolt C' is to fit into each groove of the H-bar thereof, a
block E Figures 1, 6 and 7 preferably provided with a head E'. Each of these
blocks is perforated as at E' E' and E the first mentioned holes E' receive
the rivets F Figure 7 which bind the blocks E to the H-bar which latter is
provided with holes corresponding with E and E³; the holes E³ receive the
pivot bolt C, and the holes E receive the rivet F¹ which does not pass through,
but below the end of the H-bar the adjacent faces of the two heads E' through
which F passes being adapted to abut against each other beneath the central web
of the H-bar. The pivot bolt C' passes through the cheeks of the bracket C in
which it is retained by means of a nut C or other equivalent device such as
a cotter.
At the head of each derrick A I provide a suitable housing G for accommodating
the necessary sheaves G₁ for the boat fall H. In Figure 2 three of such sheaves
are shown and I find that a convenient number to use, but any other suitable
number may be employed.
The two
At a suitable position upon each derrick I provide a support J in the upper part
or arm of which is rigidly secured the boat chock J' hereinafter referred to as the
fixed chock. This support J may be constructed of iron plates of preferably
triangular form with the apex Ji horizontal and conveniently rivetted say, by
means of angle iron bars, to the outer side-web of the derrick bar A.
principal plates, of which this support is constructed are secured together as by
bolts passing through distance blocks at such distance apart as to enable the bar.
to move freely between them. This bar J is pivotted on the bolt J rigidly
mounted in the apex end of the support J, and has secured to one of its ends the
second boat chock J' hereinafter referred to as the movable chock, its other end
being set or bent to a convenient shape so that when it is allowed to fall, it may
abut against the underside of the fixed chock J', as indicated in dotted lines in
Figure 1, and thereby be prevented from falling beyond the required limit. In
the lower arm of the support J I pivot a lever catch K K' which, by engaging
with its hooked arm K, the inner end of the chock bar J' retains the movable
chock J' in its working position; the arm K1 of this lever is sufficiently heavy,
with or without being additionally weighted, to retain the hooked arm Kin
engagement with J' and the arm K¹, if desired, may be perforated as at K' to
serve for the attachment of a releasing cord (not shown in the drawing) and also
by embracing the bolt fid or equivalent Je to limit the movement of the lever
catch K K'. Other means may however be employed for limiting the movement
of the lever-catch K K' which may itself be replaced by any other suitable
catch-device.
A rope or chain, not shown in the drawings, may be connected to the inner end
of the chock-bar J³, for the purpose of pulling that end down, and therefore the
outer end carrying the movable chock J' up, after it has been lowered for
disengaging purposes; this rope or chain may be guided through suitable openings

page_text: or
over pulleys provided in or upon the derrick or otherwise conveniently
arranged.
For retaining each derrick in its vertical position I may provide a safety-hook
or, as shown in the drawings, a fid L which latter as shown clearly in Figure 5, is
adapted to pass through a hole or slot in the web of the derrick bar A, and
corresponding holes in the two, arms of a yoke L' secured to any convenient fixed
part of the vessel, as for example the edge of the boat deck M as indicated in
Figure 1. The fid L is attached by a chain or equivalent L' (only part of which is
shown in Figure 5) to the yoke L or other convenient part and it is provided with
a bole L' for receiving a pin L, Fig. 1 (also attached by a chain to an adjacent
part) for preventing the accidental withdrawal of the fid L.
Only one fall H is used on each derrick A and this, as shown in Figure 1 may
be rove from a standing block N to a block O to which the boat B is connected,
the fall, at an intermediate part merely passing over the sheaves G' in the head of
the derrick. The standing block N may be mounted on a standard n¹ secured in
any suitable position to the boat deck M or it may be mounted in any other con-
venient manner.
A hook B' for engaging with the eye O' of the pulley block O or other ordinary
disengaging gear is fitted in the boat B for the attachment of each fall H, and is
supplemented by another hook B2 secured to or forming part of the hook B₁ as
shown in Figure 2 or fitted independently in the boat B for receiving the
suspension-hook P hereinafter described.
In the head of the derrick A preferably on the sheave pin G' I fit a suspension
rod P having the suspension hook P pivotted on a pin P' in its lower end aud
working between the sides of a long eye P into which the suspension rod Plat
that part is formed. The suspension rod P1 may be provided, at a convenient
point with an eye P on the side next the boat fall L, the standing end H¹ of the
fall H being rove through the eye P' so that the proper position of the rod P¹
with relation to the fall may be assured.
At a suitable position on cach derrick, conveniently at the underside of the
overhanging portion thereof as shown in Figure 1, I pivot a cranked bar Q
preferably by means of a bridge piece Q¹ which spans across the horizontal part
of Q and is rivetted or otherwise secured to the outer side-web of the derrick bar A.
The free arms of the bar Q which arms extend upwards on either side of the
derrick bar A are connected together by a cranked bolt, or yoke Q2 retained
therein by split cotters or equivalent devices Q all as shown clearly in
Figures 3 and 4. The eye Rat one end of a guy rope or derrick span R is
engaged with the bolt Q the other end of R being secured, as by a clasp R2, to
the before mentioned standard N¹ or to any other convenient part of the vessel or
the boat deck M thereof; this derrick span R serves to maintain the derrick A
in the required position when lowered. On one end of the bolt Q is mounted a
link S connected to one end of a chain S¹ conveniently led over the head of the
suspension rod P, which head for this purpose is preferably formed with a rounded
surface as indicated in dotted lines in Figure 1. The chain S¹ is secured against
lateral displacement, on one side by a washer or disc S mounted on the sheave
pin G and on the other side by the adjacent wall of the housing G. The lower
end of the chain S¹ is permanently attached to a lug 1 of the suspension hook P
and at a suitable part between the suspension hook P and the head of the suspension
rod PI provide a weight Pa sufficiently large to pull the bar Q into the position
shown in Figure 1 whenever the derrick span R is slack, so as to enable the
suspension hook P to fall into its engaging position.
It will be seen that S' forms practically a continuation of R; if desired it may
be formed as an integral continuation of R the necessary connection with Q being
made in any convenient manner, the derrick-span R and chain, rope or equivalent Si
as a whole are herein sometimes referred to as a
"
" connection or may be
replaced by a sliding or other suitable device allowing of the necessary limited
motion between R or S¹ and the derrick A.

page_text: The derricks are connected together by the usual span T extending from o
to the other (if two be used) and by spans T' extending from the outside of the-
derricks to suitable eye plates (not shown in the drawings) in liue with the pivots C'
so that the whole may pivot as one piece.
The fall H may be connected by the straight lead H2 passing under the roller N
to a convenient winch or hauling device not shown in the drawing.
When the derricks A are not so conveniently placed as to sustain the weight of
the boat on chocks the latter may be fitted in the usual manner on suitable beams.
or deck houses and the boat raised up to clear the chocks before the derrick is.
lowered in this case two or more boats may be housed below the same derricks..
1;
Where the boats are carried in chocks fitted on the derricks as before described.
and illustrated in the accompanying drawings the operation of lowering is as
follows:-
The falls H being held on a pin or winch end the safety hooks or fids L are
cleared from the derricks A and the lever catches K K' knocked or drawn back
so as to allow the outer chocks J' to fall as indicated in dotted lines in Figure 1.
The boat B is then swung outwards and lowered into the water by slackening out
the falls H, the derricks A carrying it clear of the vessel's side. The boat is held.
in the suspension hooks P and the derricks fall outwards until the guys or derrick.
spans R tighten when the derricks are arrested and through the links S and!
chains S the suspension hooks are opened as indicated in dotted lines in Figure 1,.
and the boat B lowers vertically into the water.
The raising of the boat out of the water is effected by engaging the eyes O' with
the hooks B and hauling on the tackles, the boat rising vertically until it touches
the suspension rods P₁, metal shoes J being preferably arranged in the boat B.
to prevent the rods P₁ slipping, after which, by further hauling, the derricks A
are raised and the derrick spans R thereby slackened so that the suspension
hooks P are allowed to close on the hooks B³. After the derricks have travelled
almost home the books P suspend the boat, and carry it straight against the
chocks J when it is only necessary to close the outer chock by pulling down
the inner ends of the chock bars J' until they are caught by the lever-
catches K K. The fids L are then replaced and made fast and the boat is
housed, requiring only to have the ordinary grips replaced to make all secure.
With this arrangement, one man at the falls H and one to release the chocks J*
and safety hooks or fids L is all that is required for lowering a boat into the
water, when, if an automatic disengaging gear is employed the boat will be free.
The usual slewing of davits is therefore entirely avoided together with the
relatively large number of men required to effect it and the time occupied in
lowering a boat is reduced. No screw or other gear is necessary for putting the
derricks A out as the weight of the boat is utilized for that purpose, and one tackle
only is used for both operations of putting out the derrick and lowering the boat.
Although I have herein described the improved boat lowering and housing
apparatus as comprising two derricks, which is the number I prefer to employ,.
in the case of the boat being fitted with fore and aft sling suspension gear one
derrick only would be necessary.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. Simultaneously lowering a boat and a derrick to which it is attached at one
stage of a boat-lowering operation and lowering the boat independently of the
derrick at another stage of the operation by the same fall.
2. Raising a boat independently of the derrick to which it is attached at one
stage of a boat-raising operation and the boat simultaneously with the derrick at
another stage of the operation by the same fall.
3. In apparatus such as described the combination with a derrick of a rod such

page_text: as P¹ which by the action thereon of the boat when being raised causes the derrick
to be raised simultaneously therewith substantially as described.
4. In apparatus such as described the combination with a derrick of a suspension
hook and a chain cord or equivalent attached to the hook and to a fixed point so
that when the derrick reaches a certain position during the lowering of the boat
the cord tightens and disengages the hook from the boat and when it reaches the
same position during the raising of the boat the cord slackens and allows the
hook to re-engage with the boat substantially as described and illustrated in
the accompanying drawings.
5. In apparatus such as described the combination with a derrick and a suspension
hook of a combined derrick span and hook-operating connection such as R S¹
substantially as described and illustrated in the accompanying drawings.
6. In apparatus such as described supporting a derrick in its lowered position
and disengaging a boat-suspension hook by the same span or connection.
7. In apparatus such as described a combined derrick-supporting and hook-
operating connection and cranked bar such as R S¹ Q substantially as described
and illustrated in the accompanying drawings.
8. In apparatus such as described the combination with a derrick and boat
raising and lowering tackle in connection therewith of an automatically-operated
boat-engaging and dis-engaging suspension hook substantially as described.
9. In apparatus such as described the combination with a derrick and one fall
for effecting the lowering or raising of the boat simultaneously with and indepen-
dently of the derrick of a suspension hook such as P rod such as P¹ and combined
derrick span and hook-operating connection such as R Q S' substantially as
described and illustrated in the accompanying drawings.
10. In apparatus such as described in the last preceding claim the combination
with the rod P¹ of an eye such as P substantially as and for the purpose described
and illustrated in the accompanying drawings.
11. The combination and arrangement of parts constituting the complete boat
lowering raising and housing apparatus substantially as described and illustrated
in the accompanying drawings.
Dated this 7th day of June 1894.
CHAS. D. DOXFORD.
W. P. Thompson & Boult,
Agents for the Applicant.