Wooden Decks Taken from an old book on ship repair, name
and title unkown
- By Bruce Beveridge
most vessels of medium or large size have their exposed
decks covered by wooden decking; the wood may be laid over
steel deck plates, or may rest directly upon the steel beams
and stringers. Teak wood decks are the finest, and
are seen on all good yachts; yellow pine is used for many
commercial and naval craft, and white pine, fir, spruce,
and cedar are also common.
PIECES. - The wood decking of large vessels is
separated from the side of the ship, or bulwark, by a gutter
way. The outer boundary of the decking is formed by
a wide plank, which is variously known as a plank sheer,
margin plank, or as on wooden vessels, a covering board.
Other wide planks are also fitted around hatches and scuttles,
at transverse boundaries, and as foundations around barbettes,
winches and other machinery. These margin pieces should,
when possible, be teak.
TYPES OF DECKING.
- Two styles of decking are in general use.
In one, the strakes of deck planking are arranged fore and
aft, parallel to the centerline of the ship. At the
ends of the ship, where the deck narrows to more of less
of a point, the ends of the narrow planks are nibbed into
the inner edge of the wide sheer plank, the latter having
a series of corresponding notches. In the other style
of decking, the narrow planks run parallel to the margin
plank-i.e., follow the plan contour of the ship while their
ends are nibbed into a wide center piece known as the king
plank. The latter arrangement, common to nearly all
yachts as well as many passenger and naval vessels, is attractive
to the eye.
arrangement of wooden decking over a steel deck as in figure
1. is typical of that on many ships.
In this case, the steel decks are lapped and riveted, but
the laps are not joggled. Hence, to provide an even
under surface for the wood decking. Lining strips have been
arranged as shown, the liners being held by countersunk
rivets extending through liner, plate, and beam. The
wood decks are held in place by bolts attached to the liners.
2. Shows decking arranged in a simple fore
and aft style, the plank ends being nibbed or "stepped"
into the margin plank. Beneath the margin plank is
a narrow plate of similar contour, called a stringer plate,
which serves to tie the decking to the sides of the ship;
it is overlapped by the margin plank a distance of two or
three inches. Other margin pieces of wide plank are
also shown about the small hatch opening; and here again
the use of steel plate at a deck boundary is illustrated.
is also a perspective view of a portion of a king
plank, which is situated in a fore and aft direction
and directly on the centerline. Beneath
the king plate, and somewhat wider, is the tie
plate, which is similar in purpose to the stringer
plate just mentioned. The tie plate gives
strength to the deck where it is most needed,
and, as may be seen, it provides a landing place
for the nibbed plank ends. The thickness
of the tie plate naturally causes an uneven surface
on top of the beams and, as in the case of butt
plates, it is necessary to fit filler strips of
corresponding thickness along the beam flanges.
The king plank shown in Figure
3a is similar to racing yachts,
being made wider in way of the mast.
NIBBING- Nibbing is illustrated in Figure
3b. Nibbing is used to avoid
pointed or, as they are correctly known, feathered
edges. The latter would be nearly impossible
to caulk. The tapered plank is always cut
off, or nibbed, at a width of a full two inches
so as to admit the edge of a 2" caulking
iron. This also permits edge-nailing, when
required, which would be impracticable with a
thin or feathered edge.
- CONSTRUCTION UNDER BITTS- The use
of specially shaped, wide planks, serving a similar purpose
to margin and king planks, is shown in Figure
4 through 6. The bitts in Figs
4 and 5A are situated at an angle to the
fore and aft decking, and the use of nibbing is clearly
indicated. The bitts must, of course, be strongly
secured, and it is usual for their long fastening bolts
or rivets to pierce a heavy doubling plate which is riveted
to several beams beneath wood, steel, or wood and steel
deck. The use of a header, consisting of a heavy I-beam
or channel arranged in a fore and aft direction between
deck beams, is also common beneath bitts.
LAYING THE PLANKING-
The fastening of the deck planking is most important.
It is customary to cut, shape, and fit the wood in place,
and then to squeeze the planks to each other by means of
dogs and wedges, before drilling the bolt holes. This work
may be carried out as in Figure
6 where the decking is seen laid upon a
3/8" filler strip, which in turn rests upon the flange
of the deck beam. The squeezing effect is obtained
by the wedges, as shown, bearing against the dog, which
is formed from a piece of angle bar; the small triangular
plates fastened to the ends of the angle dog serve to keep
it in proper line upon the beam flange. The dog may
be set at any desired spot upon the beam by the use of the
The decking being tightly
held, the bolt holes are drilled from below, the previously
punched holes in the flange of the deck beam guiding the
drill. After the holes have been drilled through,
they are counter boared from the top side of the decking
so as to provide countersinking for the bolt heads and deck
plugs. This counter boring is done to a certian depth,
regulated buy the gauge. An improvised gauge may consist
simply of a small square of hard wood, drilled, and set
at the desired distance from the point on the bit.
The bolts are usually driven from the top until they are
hard down and far enough through to secure a nut, although
the bolts are sometimes driven from beneath; in such cases,
the slotted nut, turned by a large screwdriver of the tee-handle
variety, is covered by the deck plug. When driven
from above, deck bolts should have a small grommet made
of lamp wick, soaked in white lead, under their heads.
If driven from below, the nut should have a similar grommet.
The nut being set up hard, the wooden plugs are dipped in
white lead and driven in; they are arranged so that their
grain runs the same as that of the decking; they are, of
course, of the same material.
Deck caulking tools and methods are illustrated in Figure
7. The caulking or "making"
tool A is used to drive the oakum into the joint or seam,
after it has been opened by the deck or "dumb"
iron B. The bent tool C is also used for opening
joints, while the narrow "spike" D is used in
caulking small joints. Joints are cleaned out by the
clearing or "reefing" tool E, and the sharp or
"butt" tool F is used as a chisel in enlarging
a butt joint to proper width and depth. The peculiar,
long-headed, wooden maul used in striking these irons (not
shown) is called a "beetle".
or, more properly, the art of wood caulking is beyond the
scope of this article; and such variations of method were
in effect in different yards and in different countries.
Any attempt to lay down rules or instructions will invariably
invite criticism. Briefly, in large-scale deck caulking,
as on passenger vessels, the seams are first opened up with
a reaming iron and, being properly clean and of sufficient
depth, are partially filled with cotton spun yarn. Next,
a layer of oakum is driven on top of the cotton, as at G.
Further driving may be carried out by two men, one swinging
a maul and the other the "hawsing" iron J. Finally,
the caulked seams are filled or "payed" with pitch,
poured from a special type ladle H, a cross section of the
finished job resembling that of I. One thread of woven cotton,
followed by two threads of oakum, suffice for new decks
or decks in good condition aboard most commercial vessels,
but widely varying quantities are used in special cases.
Most small craft use only cotton.
The upper decks of some passenger vessels, ferryboats, and
cabin tops of some yachts, consist of tongue and groove
planking covered by canvas decking. Some jobs call
for a layer of roofing paper between the wood and canvas,
and it is common to lay the canvas upon a thick coating
of paint of marine glue. The strips ("cloths")
of canvas are lapped at the seams about 2", and the
fastening may consist of brass or copper tacks spaced on
3/8" centers and kept about 3/16" from the edge
of the material. Three or more coats of paint may be applied
to the exposed surface of the canvas.
section of the canvas covered decks of a New York City ferryboat
is shown in Figure 8.
Hand rails of two types, as A and B are secured to the deck
stanchions. The latter may be of pipe, as shown, so
as to serve the added purpose as drain spouts, the lower
end terminating in a bridge foot. This foot rests
upon a lead plate, and bolts extend through the deck and
and procedures are used in laying canvas decking, the object
being to stretch the cloth as tightly possible. Two
contrivances are shown in Figure
9, and their simple details are fully shown
in the sketches. On small craft, a skintight canvas may
be obtained by coating the tacked material with a smelly
and volatile preparation commonly known as "airplane
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