460

NICHOLLS'S SEAMANSHIP AND NAUTICAL KNOWLEDGE

secure at sea and to lock up the hatchway in port. The ends of this
bar project a little beyond the coaming and are secured with a clamp
at Og.

The framework of web beams and fore and afters within the coamings
offer a very precarious foothold and many accidents have occurred
through men losing their balance and falling into the hold when taking
off and putting on the sections of wooden hatch covers and strongbacks.
The modern tendency is to fit steel hatch covers either of the hinged
type to tip up in one piece like a lid, or of the Roller pattern which may
be in one piece, or in sections, and rolled back horizontally to uncover
the area of hatchway required. The steel covers are stronger and less
vulnerable to the inroads of heavy seas than wooden covers.

The Stem Bar is a forged bar of iron or steel. It is scarphed to the
bar keel when one is fitted and forms a continuation of the latter. The
connection between a flat plate keel and the stem bar is formed by

Fig. 49.
troughing, or dishing, the forward end of the keel plate round the end
of the stem bar and riveting both together. The stem is also connected
to the structure by the shell plating, the strakes of which lap on each
%side of the stem as in Figure 49 where A is the stem bar, B and B the
shell plating, and G 0 a double row of rivets.
Panting is more likely to occur in sharp vessels than in blufl-bowed
•vessels. The curvature of a bluff bow is an element of strength in
itself and helps to resist panting.
Panting Beams are fitted across the interior of the vessel, usually'
on the fore side of the collision bulkhead.
Their strength is distributed over the frames and shell plating by
means of the stringers to which they are connected by brackets, or
gusset plates. Two brackets used together are sometimes called a
gusset. The stringers themselves are sometimes stiffened and widened
where panting might occur. Other parts of the vessel which help
to stiffen the frames and shell plating and thus prevent panting are