d. Caulking thin plating. Generally, it is not advisable to drive wedges into cracks in thin plating, especially
hardwood wedges, as the wedges tend to open the cracks. Marline, oakum, and rags often can be used as effective
e. Caulking torn seams. Among the most difficult holes to plug are torn seams or loose bounding boards where
deck and bulkhead plates are joined. It is not advisable to weld leaky riveted seams because the intense heat will cause
adjacent rivets to leak. Rags, oakum, marline, soft wood wedges, shingles, lead strips, lead wool, and various plastics
have been used to plug such leaks, and even metal caulking. These materials are applied on the unflooded side, but
because the plates work, the cracks open and close. This usually permits the plugging materials to be washed out.
f. Doors and hatches sprung by blast. Doors and hatches often are sprung by blast, especially if they were not
properly secured. Often the closure can be made tight with shoring. If small spaces are open between the closure and
the knife edge, these can be treated as cracks. In some cases, the damage is so bad that it is better to remove the
closure entirely and to replace it with a mattress backed by a shored plate.
g. Leaky stuffing tubes, shaft glands, and rivets. Stuffing tubes around electric cables and reach rods frequently
leak, either because they were not properly packed or because the packing has hardened with age. Sometimes it will
suffice to tighten up on the packing nut. Marline, oakum, and very small wedges have been used effectively. Action
must be taken to insure that they are properly packed at all times and checked with periodic air tests.
Leaky shaft glands have been repaired by tightening up on the nuts. In others, the studs have been broken so it was
necessary to shore the whole gland back in place, preferably with welded braces. In one case, the leak was so bad that
the ship made a type of box patch in two sections, secured it around the shaft, and welded it over the gland. In effect,
the ship made a new gland.
Leaky rivets are not easy to repair. Frequently, rivets are pulled through plating but remain so close that wooden plugs
cannot be driven home. Slugs cut from sheet lead have been used to good advantage, as have lead wires, marline, and
red lead. Caulking sometimes helps.
Section V. STRENGTHENING BEAMS AND FRAMES
8-12. METHODS. Beams, frames, and decks, and some bulkheads are strength members of the hull structure and if
they break or become weakened, the hull may collapse and the ship break in two and sink. A small ship may not have
the necessary equipment to weld on heavy rails or angle irons about the ship to give additional support, but some help
can be obtained by shifting weights to reduce the strain, and by shoring. Beams and frames can be patched or
strengthened by bolting or welding doubling plates or bars along the webs. FIGURE 8-3 shows