DIXON KEMP
Manual of Yacht and Boat Sailing and
Architecture
(11th and final edition, 1913)
C: Cable -
Check.
-
- Cable.--
A rope or chain by which a vessel is held at
anchor.
-
- The length for a cable, according to the
Admiralty, is 120 fathoms. The length of a cable
for a yacht varies from 45 fathoms for a 10-tonner
to 150 for a 300-tonner. A yacht of 60 tons should,
however, have at least 75 fathoms.
-
- Cable's Length.--
A measure of one-tenth of a sea mile, 600 feet,
101 fathoms, or 203 yards.
-
Caboose.--
The cooking room or kitchen of a merchantman.
Also the "galley fire" or cooking stove of a yacht
or ether vessel.
-
Cage Buoy.--
A buoy with an iron framework upon the top.
Formerly "cages" were put on poles in intricate
channels, and for two hours about the time of high
water at night fires were lighted in them.
-
Call.-- See "Boatswain."
-
Callipers.--
An instrument consisting of a "straight edge"
beam with two legs, used for measuring the breadth
of yachts, packages of merchandise, &c. Metal
bowlegged compasses called callipers are used for
measuring the diameter of spars.
-
Calm.--
Stillness of the air. Stillness or smoothness of
the sea. An unrippled sea. Dead calm, stark calm,
flat calm, clock calm, glass calm, glass smooth
sea, &c.
-
Cambered.--
When the keel of a vessel has its ends lower
than its middle, thus xxx . Opposed to
rockered.
-
Canoe.--
A kind of boat used in many parts of the world
and distinct from row boats, as they are propelled
by paddles, with the crew facing forward. There are
paddles of one blade and two blades. Some canoes
carry many occupants, some only one. They are
variously built and usually sharp ended.
-
Canoe Hatch.--
The double lines C are carlines, supposed to be
seen through the hatch which is screwed to the two
doffed ones (Fig. 11); the ends of the latter are
made to slide in a groove in the coamings. The
middle carline is fastened to the deck and prevents
the latter sliding too far, and stops the water
getting into the well should any find its way under
the hatch carline. A channel should be made round
the rim of the well so that the person sitting
therein could fit an apron or waterproof into it
after the fashion of the Esquimaux.
-
Fig. 11
- A preferable plan is to have the hatch and the
frame on which it slides separate, so that it will
fit over the rabbets round the coamings; then if
the canoe upsets, the hatch will float off and free
the canoeist.
-
- Mr. Redo Turner recommends the following plan
for fastening down a canoe hatch :
-
- A is a metal plate, screwed to hatch or door,
and projecting somewhat beyond the edge of hatch,
and in the projecting edge of it has a slot cut.
(See Figs. 12, 13, 14, 15.)
-
Fig. 12.
- B is a screw at one end, and on this end works
a butterfly nut (C) (Figs. 12, 13, 14) the other
has two short arms at right angles to the upper
part (see Figs. 12, 13, 14) which short arms are
hinged at D (Fig. 13), and B moves freely when the
butterfly nut C is unscrewed.
Fig. 13
- To open a hatch which has been fitted with this
arrangement, the two butterfly nuts C must be
unscrewed, and B allowed to fall down out of the
way, and the hatch can then be lifted off. To
fasten the hatch down B must be turned up, and the
butterfly nut C screws down tight.
-
- N.B. There should be two or more of this
arrangement on hatch, according to the size, viz.,
one on each side.
Fig. 14.
- Fig. 14 is the same plan, except that B is
fixed upright, and the plate A is centred on E, and
works horizontally. (See dotted lines of Fig.
14.)
Fig. 15 (goes with Fig. 12 and 13.)
- Cant Frames.--
- The frame in the bow and quarter of a vessel
that are not square to the keel.
-
Canvas.--
- The weight of canvas used by Messrs. Lapthorn
and Ratsey for yachts' sails is as follows :
- [table]
Canvas Back.--
- A term applied to boats covered with canvas to
keep out the seas; also applied to yacht sailors
who are fond of a salting.
-
Canvasback Duck.--
- A wild duck common in America, and highly
esteemed for the table.
-
Canvas Boats.--
- These are boats made of canvas and used by the
Galway fishermen, particularly at Dingle. The ribs
of the boats are made of wood hoop, such as may be
got off casks ; outside the ribs battens are nailed
in a fore-and-aft direction; a keel to which the
ribs are also nailed is rounded up at the ends to
form stem and stern post. The canvas is about two
feet wide, and runs fore-and-aft. There is an
inwale and gunwale as usual at the top of the ribs,
the canvas going between the two. These boats are
usually 20ft. by 4ft. They are very light, one man
carrying them easily. They are manned by a crew of
four, each man using a pair of oars. A lug sail is
carried off the wind. These boats get through a
great deal of rough water by aid of the eight oars
they are propelled by.
-
- I. The following directions for making canvas
boats have been carefully compiled :--
-
- For the keel get a piece of larch 15ft. long,
2-1/2in. wide, and 2in. deep ; the stem and stern
posts, with rake according to fancy, may be halved
into the keel; these pieces must be bevelled off
from the width of the keel, so as to have a
cutwater of about half an inch, which will be sharp
enough. Next get three good heavy blocks of wood,
and lay them four feet apart in the place where you
are going to build your boat; then take the keel
with the stem and stern posts already in, and fit
it perfectly true on the said blocks, using a
spirit level for the purpose. The easiest temporary
way of fastening the keel down is to nail short
pieces of wood firmly to the blocks, just wide
enough apart for the keel to jam between them, and
drive a small nail through these pieces into the
keel on each side; this will keep all firm, and
prevent the keel from moving or twisting as you
proceed with other work; it is an important point,
and must not be omitted.
-
- This done, the next thing is to get a good
stout spar, about 2in. or 3in. square, and longer
than the boat; tack this on the top of the stem and
stern posts; as it is necessary that this
fore-and-aft piece should be stayed stiffly in its
position, this can easily be done by tacking some
rough pieces to it here and there, and nailing the
other ends to the rafters of your shed. The uses of
this spar are many and obvious. You will thus get
your stem and stern posts true, and it will be
useful afterwards to keep the moulds in their
places, and for shoring out the timbers and
ribbands or battens so as to keep them shapely to
the eye as the work proceeds.
-
- Your next business is to make what shipwrights
call "the moulds," which is to give the shape,
beam, and depth. To make the moulds, first strike
it out full size with a piece of chalk on the floor
of some room. For a boat 15ft. in length, the width
ought to be at least 4ft., the depth not less than
2ft. Do not let the curve of the sides be too
sharp, but give her a good hard bilge and a
flattish bottom. Having made your moulds to the
exact shape of the pattern chalked on the floor,
nail a thin strip of wood across the upper
(gunwale) ends, which will keep them stiff and
true; next take the moulds and nail them on the
keel in their proper places, fastening it above to
the fore-and-aft piece.
-
- The moulds being now firmly fixed in their
places, you may proceed to what in other boats
would be called the planking. Saw out some thin
strips of larch, about 20ft. long, 1in. wide, and a
quarter of an inch thick. Six of these on each side
would be sufficient. Having chamfered off a little
from one of the ends to make it fit the stem of the
boat, fasten it with two small copper nails ; carry
the ribband in your hand, and humour it gently
round the moulds tacking it slightly there, and
bring it on to the sternpost. You will probably
find your piece too long; mark the required length,
cut, and nail it in its place. In laying on these
ribbands you must begin at the bottom of the boat,
and work up.
-
- Having fixed your ribband both sides, get two
long pieces the same width, only double the
thickness, for gunwales, and fix them; fit a breast
hook stem and stern, and rivet the gunwales
securely to them. Saw out a lot of thin stuff for
ribs, half an inch wide, and about the eighth of an
inch thick; they will bend easily, and will not
require steaming. Put these on about six inches
apart, and rivet them to the battens.
-
- Next put in your thwarts, fixing them well down
in the bottom of the boat, which will make her
safer, the weight being near the keel. Get some
copper, galvanised iron, or oak knees, with one leg
long enough to reach from the gunwale down to the
seat; rivet this well to the battens and gunwale,
and nail the other part on the seat; there should
be four to each thwart, as they help to strengthen
the boat immensely. You may now take your boat off
the stocks, and she will be ready for the next
operation.
-
- Get some good new sail canvas, not too stout,
and cover one side at a time ; tack the edge of the
canvas all along the bottom of the keel and pull it
to the shape of the boat, tacking it neatly to the
sides of the stem and stern posts. Where you find
it does not sit well, you may sometimes avoid
cutting by folding the spare stuff, and, with a
sailor's needle and palm, sew it to the main body
of the canvas. Do this on a warm day, as the canvas
will then be quite supple, and more easy to
handle.
-
- Nail a strip of wood half an inch thick on the
bottom of the keel to keep all snug, and as an
extra security drive a row of tacks through the
canvas on each side of the keel. You must be
careful to nail over the canvas some narrow strips
of wood, as "bilge pieces," where you see she would
take the ground when lying on her side, otherwise
the pulling and dragging over the sand in
launching, &c., would quickly wear the canvas
through. With care, and with an extra coat of paint
now and then, a boat of this sort will last nine or
ten years.
-
- The following suggestions will be found
effective to prevent the puckering of the canvas
skin of the proposed boat. A framework of 4ft. beam
will require about three breadths of canvas on each
side, and waste should be avoided by preparing
paper patterns by which to cut out the canvas. To
do this cut some old newspapers to the width of the
canvas, and paste sufficient pieces together end to
end to give the required length of the boat. Turn
the frame of the boat upside down, and stay it in a
horizontal position and upright. Lay the edge of
the paper on the flat keel along the middle, place
weights upon it and measure off the distances from
the middle line across the paper on the ribs, so as
to keep the breadths horizontal from the middle to
the stern and bow of the boat. Towards the bow and
stern the breadths will be of course materially
reduced. Remove the paper on to the floor, and draw
a line from point to point marked on the paper at
the crossings of the timbers.
-
- From this pattern you can easily cut out the
two canvas strakes, one for each side of the boat
against the keel, which are called the garboards.
Replace the pattern ; but, before doing so, mark
the lower edge for the second breadth of paper,
and, setting off the distances along the ribs to
the width of the first pattern, you will be able to
mark it out and cut it as the previous one. A
double seam will be better than a single, as it
will give great additional strength to the canvas,
and the width of an inch and an eighth should be
allowed for it. The lower edge of the third breadth
can now be marked and cut out by the upper edge of
the second, and if found to reach the gunwale, the
top edge may be left uncut until the canvas is
drawn over the framework. In applying the canvas to
the keel, put plenty of thick paint on the inside
to half the breadth of the keel, and nail the
selvedge with copper tacks along the middle line;
then screw on with brass screws, at 6-inch
intervals, a piece of elm plank 3/8 of an inch
thick, and exactly the same width and length as the
keel. Between the 6-inch intervals drive copper
tacks. A small strip of copper at the forefoot and
heel will prevent this shoeing, as it is called,
from catching in anything.
-
- To make a good finish at stem and stern, cut
out the thickness of the stem and sternpost to the
eighth of an inch from top to bottom, as in an
ordinary boat, which will form a groove or rabbet,
and when you come to this part fold the end of the
canvas hack. This will give additional strength for
the nails, and at the same time make a very snug
finish.
II.
-
- A diagonal-framed canvas boat built in 1841 was
in use for thirty years. The canvas was stout, and
it was very thickly painted when dry, and not
wetted, as is frequently the case, to prevent the
absorption of paint. The boat was built on three
moulds, the transom or stern board (for she is not
canoe-formed at the stern) being one mould, the
midship mould the second, and a third equidistant
between it and the bow. An inner keel or kelson
having been connected with the stem and sternposts
by mortices, this kelson was let into the moulds
its own thickness, 1in., and secured.
- The moulds were steadied in their positions by
the gunwales, of 1/2-in. by 2in. yellow pine,
nailed to the stern and transom board. The frame of
yellow pine, 3/16in. by 7/8in., was then nailed on
diagonally, leaving openings of 2-1/2-in. wide
where crossing each other. The canvas, put on
lengthways, was cut so as to run along the
framework parallel with the kelson on each side;
and the seams were sewn double, as sails are
ordinarily made by sailmakers. There is one bottom
and two side breadths, and, therefore, no join
along the kelson. The canvas turns in over the
gunwale, and is secured by a strip of the same
wood. The framework is nailed with copper tacks.
The canvas, being so well supported, is perfectly
rigid, and the boat appears likely to last a number
of years. See "Collapsible Boats."
-
-
- Canvas Canoes.--
- Such a boat (Fig. 16) was built by Capt. J.
Richards, R.N., in 1878, for the river Avon, 12ft.
long, 3ft. wide, and 15in. in depth. She has a
frame of American elm, fastened with rove and
clench copper nails and wire ; her floor is nearly
flat, formed of 3/4-in. white pine wood, lined
inside with sheets of cork to fill up the spaces
between the timbers, and form a level and solid
platform within. Above the floor and outside the
timbers (which are 6in. apart, and twenty-three in
number), instead of the planking of an ordinary
boat, there are stout fore-and-aft stringers of
American elm three inches apart, outside all of
which is stretched the thick No. 1 canvas skin of
the outer boat. The principal materials required
are keel of 1in. square ash ; gunwale, 1in square
ash ; crosspieces of gunwales, 1in. square ash ;
keel chafing pieces, 3/4-in by 1/2-in. ash ;
fore-and-aft stringers, 1/2-in. by 1/4-in.; bilge
stringers, 3/4-in by 1/2-in. ; twenty-three
timbers, 3/4-in. square.
-
- Within this structure and securely attached to
it, although quite distinct from it, there is an
inner canvas boat, 8ft. long and 2ft. wide (having
a separate gunwale), in which the crew sit on the
floor.
-
- The deck space between the gunwale and coaming
is entirely covered in by canvas, supported on a
strong framework of wood and cane; and, being under
ordinary circumstances quite secure from wet, was
intended by Capt. Richards for the stowage of
bedding, clothes, and provisions of the crew.
-
-
-
FIG. 16.
-
- The gunwale and the coaming are strongly braced
together, and the ends of the gunwale are
additionally secured to the stem and sternpost by
strong iron plates, with eyebolts above, in which
are rove stout ropes, to moor the boat with when
afloat, or suspend her to trees like a hammock
whenever her crew may desire to sleep in that
position.
-
- The coracle is fitted with a couple of small
light wheels and iron axle (weighing only about
12lb., and movable at pleasure in about a couple of
minutes), which when attached to her keel afford
her the locomotive advantages of a porter's
truck.
-
- The twelve-foot coracle weighs about 90lb., and
draws three inches of water when light; but, with
her crew of two men and her gear on board, she drew
five inches forward and seven aft. An inch of this,
however, is due to her false keel, which, with
bilge pieces, give some lateral resistance when
under sail in a seaway.
-
- The entire structure was well saturated with
boiled linseed oil, and then painted.
-
- The inner boat can be disengaged at the
gunwale, and removed altogether in about four
minutes. One of the principal advantages claimed
for this "double-shell boat" consists in the fact
that the outer boat may be stove in without
rendering her unserviceable or wetting her crew;
and so long as the outer boat is intact, a sea may
be accidentally shipped in the inner boat without
dangerously affecting the stability of the vessel;
and should both the outer and inner boats be
swamped with water, the cork floor and cushions
will, nevertheless, still afford her the properties
of a life buoy sufficient for her crew. (See
"Coracle Life boat.")
-
- The builders of these boats were Messrs. Hill,
Canon's Marsh, Bristol.
Price 6£ 10s. Carriage by rail 1d. per
mile.
Cap.--
- A figure of 8 iron band fitted to the masthead,
bowsprit end, for jib boom, &c. Sometimes the
yoke is termed the lower cap.
-
Capful of Wind.-- A puff of wind soon passing
away.
-
Capstan.--
- A mechanical contrivance for raising the
anchor, said to have been introduced in Queen
Elizabeth's reign. Sir Walter Raleigh says: "The
shape of our ships have been greatly bettered of
late. We have contrived the striking of the
topmast, added the chain pump, devised studding
sails, top gallant sails, sprit sails, and
topsails. We have also lengthened our cables, and
contrived weighing of the anchor by the capstan."
Capstans very compact ill form are now made for
yachts instead of the cumbrous windlass. The
capstans most generally in use on board yachts are
those manufactured by Reid and Co., Paisley;
Cantelo, Southampton; W. White and Sons, Vectis
Works, Cowes; Atkey, Cowes; Harfield and Co.,
Mansion House Buildings, E.C.; Blake and Sons,
Gosport; and Simpson and Strickland, Dartmouth. The
Reid, Cantelo, White, and Atkey capstan have winch
heads so that they can be used without capstan
bars.
-
-
FIG 17.
-
Capstan Bar.--
- Bars of wood by which the capstan is turned,
and so made to wind up the anchor or raise any
weight.
-
Capstan Driven by a Motor.--
- The practical difficulty about applying an
ordinary motor engine to a capstan with a common
clutch gearing is that the motor runs at a high
speed, and the sudden violent strain coming on the
chain from the capstan with great force and shock
is apt to break down the motor. Capt. E. du Boulay
has invented a system which it is claimed will
overcome this difficulty by means of a reducing
gear which the firm, Thellusson and Co., Cowes,
have patented. The illustration we give (Fig. 17)
of the arrangement shows how it can be applied to a
vessel. M is the main motor, driving the capstan C
through the reducing gear B and shafting S. The use
of the capstan in the ordinary way by hand is not
interfered with. The makers of this motor capstan
are Pascall and Atkey, the yacht fitters, of Cowes,
and they have fitted one of them to a 17-ton
fishing yacht which was built at Southampton.
-
Capstan for a Trawl.--
- A capstan for a trawl for a yacht of twenty or
more tons is made at the Mount's Bay Foundry,
Cornwall.
-
Card.-- The dial of a compass upon which the
points are marked.
-
Cardinal Points.-- The compass points, E., W.,
N., and S.
-
Careen.-- To heel, to list, to haul over for
cleaning the bottom.
-
Carlines.--
- Pieces of timber fitted between the deck beams
in a fore-and-aft direction.
-
Carry Away.-- The breakage of a spar, rope,
&c.
-
Carry Canvas.--
- A vessel is said to carry her canvas well if
she does not heel much in strong breezes.
-
Carvel Built.--
- Built with the plank flush edge to edge, and
the seams caulked and payed.
-
Cast.--
- Said of a ship when she fills on one tack or
the other after being head to wind. Used generally
on getting under way, as cast to port, &c. The
word is variously used, as to cast anchor, to cast
off a rope.
-
Catamaran.--
- A small raft common in the East Indies. A
double boat in use in America.
-
Cat Block.-- The block used in catting the
anchor.
-
Cat Boat.-- A boat with one sail, like a Una
boat.
-
Catch a Turn.--
- To take a turn quickly with a rope round a
belaying pin, or bitt, or cavel.
-
Cathead.--
- Timber or iron projection from the how of a
vessel by which the anchor is hoisted up to the
rail, after it has been weighed to the hawse
pipe.
-
Catspaws.--
- In calms, when the water is rippled here and
there with passing airs of wind, it is said to be
scratched by catspaws. A "catspaw" is also a bight
doubled in a rope.
-
Caulking.-- Driving oakum into the seams of a
vessel. (See "Marine Glue.")
-
Caulking Iron.--
- A kind of blunt chisel used for driving oakum
into the seams.
-
Caustic Soda.--
- A mixture of three parts of caustic soda to two
of unslacked lime is a good detergent. The soda is
boiled in the water, and then the lime added. The
mixture should be applied hot, and be of the
consistency of thick whitewash. In applying it
great care should be exercised so as not to allow
it to touch the hands. A brush of vegetable fibre
should be used, as the composition will destroy
hair. Caustic soda is used for cleaning off old
paint or varnish; the mixture should be put on nine
or ten hours before it is scraped off if a very
clean job is desired. If it is a deck that has to
be cleaned it is desirable to damp it with fresh
water before an application of the mixture; hence
it is a good plan to apply it on a dewy morning.
Mahogany should not be cleaned with this compound,
which turns it black. A mixture of two parts soda
and one part soap, simmered together and applied
hot, is sometimes used.
Carson's "Detergent" (La Belle Savoyard,
London), is an excellent substitute for caustic
soda, but care should be taken in using it for
decks, as it injuriously affects marine glue. (See
also "Sooji Mooji.")
Cavel (sometimes spelt kavel or kevel).--
- Stout pieces of timber fixed horizontally to
the stanchions on bitts for belaying ropes to.
-
Ceiling.--
- The inside planking of a vessel.
-
FIG 18.
-
Centre-Board (a Temporary).--
- Make a 1/4-in. plate of the shape of either of
those in the sketch (Fig. 18) about one-third of
the length of the boat. Three bolts will be on the
upper edge of the board; the centre bolt will have
a thread longer than the other two, and protrude
through the keel. When the plate is fitted under
the keel, it will be held tight to the keel by a
thumb nut on the centre bolt. To unship the board
when in davits or in shallow water unscrew the
thumb nut and release the plate. A cork will be put
into the bolt hole. Of course the plate cannot be
shifted when the boat is afloat in deep water. It
would be unsafe to sail about in shallow water with
such a contrivance; nor should the boat under any
circumstances be allowed to take the ground with
the board fixed.
Another form of temporary board (Fig. 19) has
been fitted to an ordinary boat, 18ft long. It
consists of a board, to which are affixed iron
clamps on either side, which admit of the main keel
being inserted between them; through these are
passed bolts with nuts, which firmly hold the two
keels together.
FIG. 19.
-
- The dimensions of a board for an 18ft boat are
6ft. long, 1ft. 10in. deep, and 1-1/2in. thick. The
board is to be about 1ft. 6in. shorter on its under
side than on its top side, the fore end sloping
aft, and the aft end sloping forward; but the slope
at the fore end is nearly double that at the aft
end.
-
- Place the centre of the board a trifle in
advance of the centre of the main keel; it can be
fixed in five minutes when the boat is in the
davits; only one word of caution is necessary, that
is, not to tow her with the keel on behind the
yacht when sailing, or in all probability she will
take a sheer out and capsize.
-
- This plan was introduced by Mr. G. H. Harrison,
of the Siesta schooner; but it is not quite so good
as the iron plate just described, because it cannot
be unfitted or released whilst the boat is afloat;
and, moreover, a triangular shape is to be
preferred.
Centre-board (deflecting).--
- All boards of a fixed pattern are more or less
in the way, and "the American Goodrich deflecting
centre-board" (Fig. 20) was invented to do away
with all inboard casing and make a board of less
draught accomplish as much as a deep one could. It
is an ingenious, but rather unpractical,
arrangement, not to be recommended.
-
- The "board" consists of a thin sheet of stiff
metal, swung to the keel by a long binge, and can
be rotated at will by applying force to a lever at
the after end. The metal plate is 30in. long and
9in. deep for canoes, and 36in. long with 10in.
depth adapted for row-boats and general use. The
end of the shaft ships into a small lug socket on
the keel. It is held in place by turning up a screw
in the back of the after box, driving the forward
end home into the lug. To remove or unship, it is
only necessary to back out the screw, draw hack the
board until the shaft drops out of the forward lug,
then pull forward until clear of the box also. To
control the angular position of the blade, a lever
is introduced inside the canoe. The top of the
after box has an opening with a forked slide
slipping over the slot. This slide is pushed clear,
the lever then slipped into the middle hole of
three in the shaft end. If the board is to be kept
plumb, draw to the forked slide, so that the prongs
grasp and hold the lever up and down. Leakage is
prevented by having the shaft closely fit in the
box. When so nipped, the blade is vertical, the
same as is the case with an ordinary centre-board,
and in this condition the canoe is prepared to sail
in light airs, or before the wind, as it is
impossible to trice up the blade. Being small, very
thin, and with sides as smooth as you wish to
finish them, no appreciable resistance will be
experienced.
FIG 20.
-
- When heeling to a press of sail, or in beating
up against the wind, the angle of the blade may be
changed quickly to suit the demands of each tack.
This is effected by shoving hack the forked slide,
and then pushing the lever up to windward,
retaining it there by a small hook and eye supplied
for the purpose. When going about, throw off the
hook moves in a sideways direction; thus, an ardent
pressure would be brought upon the upper side of
the lee bilge keel, and this pressure would assist
in a small degree in heeling the vessel.
Fig. 21
- Centre-plate (dagger).--
- This portable plate (see Fig. 21) is in much
use in America for very small shallow boats and
canoes.
Centre-plates (the strains and stresses
of).--
- Fig. 22 shows a boat heeled by a force
represented by the arrow A, and this force also
drives the vessel to leeward in the direction of
the arrow. The motion in this direction is
resisted, more or less, by the pressure of water on
the hull and on the board B. This pressure is
represented by the arrows CC. If, now, for the
board we substitute a heavy metal plate, it is
obvious that the weight of this D plate will act in
the direction of the arrow E (Fig. 23).
The stress of the plate D acts in an exactly
opposite direction to time board B. But, supposing
the weight D exactly balanced the pressure CC on B,
the board would have no straining effect whatever,
but would rest free in its case as represented by F
(Fig. 24).
This condition of equilibrium in only likely to
endure momentarily, but the illustrations show how
a heavy board may tend to reduce the strains on the
keel and case. Of course the worst strains occur
when a vessel is rolling in a seaway, whether she
be before the wind or on a wind; and often it has
been found dangerous to keep a board lowered when
the vessel is hove-to, owing to the pressure set up
by CC, which is much greater when a vessel is
hove-to than it is when she is making high speed
through the water ; and also owing to the rolling,
which is always more or less apparent in disturbed
water.
At the time the inquiry was held into the loss
of the Captain someone raised the question
as to whether keels and bilge keels would add to
stiffness under canvas ; it was properly pointed
out at this inquiry that, so far as keels or bilge
keels of wood are concerned, they tend to decrease
statical stability, but on account of the
resistance they offer to motion in the water they
would check the sudden inclination of the vessel
due to a sudden application of wind force by
increasing time "amount of work to be done" in
heeling ; in other words, they would increase the
dynamical stability. However, as further pointed
out at the inquiry, the lee bilge keel will have a
tendency, when the vessel is sailing with a steady
wind pressure, to cause an increase of heel beyond
that due to the actual pressure on the sails. A
vessel when sailing with the wind abeam or forward
of the beam, makes more or less leeway, or moves in
a sideways direction; thus, an ardent pressure
would be brought upon the upper side of the lee
bilge keel, and this pressure would assist in a
small degree in heeling the vessel.
22
-
23
-
24
-
- It is quite a common belief that a centreboard,
irrespective of its weight, somehow increases
stiffness; but such is not the case. In is also
sometimes thought that a metal centreplate will
enable a broad, shallow boat to carry as much
canvas as can be got on her. This is a very great
mistake, and we know from two or three examples
that the effect of a centre-plate weighing nearly
half a ton on a 25ft. boat, with a 11ft. beam, and
about 1ft. 9in. draught amidships, is extremely
small on the stability ; and a "skimming dish," if
fitted with a metal centre-plate, could not in
consequence dispense with her live ballast "hiking"
out on the weather gunwale.
-
Certificate.-- See "Master's Certificate."
-
Chain Locker.--
- The compartment in the bold of a vessel wherein
the mooring chain is stowed.
-
Chain Pipe.--
- Iron pipe on the deck through which the cables
pass into the lockers.
-
Chain Plates.--
- Iron braces on the side of a ship to which the
shrouds are attached with the screw lanyards of the
rigging above.
-
Challenge Cups.--
- Cups which when won subject the yacht to be
challenged to race for it again. Unless there is
any stipulation to the contrary, a yacht can be
altered during the period she holds the cup and
still be eligible to defend it.
-
Channel Deep.--
- Said of a yacht when she is heeled over until
her lee channels are under water.
-
Channel Plates.--
- Braces secured to the sides of vessels and
extended by pieces of timber termed channels. The
rigging screws are shackled to the channel
plates.
-
Channels.--
- Originally strong pieces of timber fixed on the
side of a ship inside the chain plates to give
greater spread to the rigging. The timber is now
superseded by steel construction.
During the existence of the old tonnage rule up
to 1887 the channels of yachts were much increased
in width in order to give the necessary spread to
the rigging in consequence of the narrowness of the
hull compared with the height of the mast. But even
with this extra spread it was found difficult to
keep the mast in its place ; and in fact it could
not have been done, but for the steel wire rope
shrouds. These were set up bar taut and the drift
of lanyard between the dead eyes was very short
compared with what it once was.
From 1893 until 1910, when yachts were given
more beam, outside channels were generally
dispensed with altogether.
In some of the latest yachts (1911, 1912) owing
to their great height of sail plan in proportion to
their beam, there has been a tendency to return to
the old practice of building outside channels. The
new channels, to which powerful steel rigging
screws holding the wire shrouds are attached, are
scientifically constructed of steel.
Check, To.--
- To check a sheet is to ease it a little. To
check a vessel's way as by a warp, or by backing a
sail. To check a tide is to keep a vessel from her
course, in order to allow for the influence or
drift of a tide. A vessel is said to check the tide
when it throws her to windward. To check a vessel
with the helm is to prevent her altering her
course. (See "To Meet.")
-
..
© 2000 Craig O'Donnell
May not be reproduced without my permission.
Go scan your own damn dictionary.
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