| Tweet |
Custom Search
|
|
|
||
 TB 740-97-4
roofing cement. The paper will be carried down all sides of the hatch and secured with rough 2-x 4-inch lumber, in lieu of
hatch cover battens. The lumber will be secured with wedges. The metal batten straps will be applied over the roofing
paper.
(4) Sealing for dehumidification . Methods and materials used in sealing for dehumidification will be in accordance
with this bulletin. Detailed sealing requirements are as follows:
(a) Stack. A galvanized sheet metal blank, minimum No. 26 gage, generally in the shape of the stack opening,
but long enough to engage under the forward and aft areas of the stack lip, will be fabricated and sprung into position. A
piece of muslin, target cloth, or similar material will be draped over the stack, fitted snugly down the sides, and secured
below the top bead by pressure-sensitive tape applied as a band around the stack. The stack drain hoses will be masked
with pressure-sensitive tape. The stack side vents will be shielded with plywood or sheet metal covers secured with
suitable demountable fasteners. The covered areas will be coated with strippable coating and bituminous coating.
(b) Vents, valves, piping, drain, and other openings. Existing covers will be closed, and the items will be sealed
with strippable coating, except those used in the dehumidification system.
(c) Doors, windows, and portlights. Perimeters of exterior doors, windows and portlights, except the portlight in
the fidley, will be sealed from the outside with strippable coating. The portlights in the crew quarters may be sealed from
the outside.
(d) Scuttles and access hatches. The perimeters and center recesses of scuttles to the engineroom and crew's
quarters, and one of the access hatches to the crews quarters and lazarette, will be sealed with strippable coating and
bituminous coating.
(e) Miscellaneous sealing. CO2 system nozzles in the cargo hold will be taped, coated with strippable coating and
tagged. Points of entry of steering cable into cargo hold and pilothouse will be sealed with strippable coating and
bituminous coating.
(f) Dehumidification piping system . The points of entry of all air tubing and ducts into compartments will be sealed
with strippable coating and bituminous coating Such sealing will be carried over and around flanges, adapter, and othe
devices used in attaching or introducing the air tubing. All joints in the air tubing will be similarly sealed.
(g) Anchor windlass. The opening between the clutch engaging mechanism and the gypsy head will be sealed
with strippable coating. The windlass will be covered with a piece of canvas, and the canvas will be wired in place.
(h) Windlass speed control box. Sixteen units of bagged desiccant will be placed in the box, and the cover
immediately closed. The cover and operating handle extension through the box will be sealed with strippable coating. The
cover will be stenciled, "DESICCANT INSERTED (MONTH) (YEAR)".
(5) Provisions for air circulation . Within the areas being dehumidified, interior doors, galley range, and refrigerator
doors will be secured in open position, Covers to lockers, tanks, and void spaces will be removed and secured adjacent to
their places of use.
(6) Dynamic dehumidification installation . A dynamic dehumidification system will be installed to provide dynamic
dehumidification of the engineroom, pilothouse, main deckhouse, lazarette, and crew quarters. Dry-air lines and moist-air
return lines will be run to the lazarette, the crew quarters, and the main deckhouse, generally, as shown on figure 66.
(a) Dehumidification machine . A package dehumidifier, single desiccant bed, absorbent type, 10,000 cubic feet
capacity, 110-volt, alternating-current, will be installed, as shown on figure 66. The machine will be mounted on a stand
and protected by a cover fabricated in accordance with figure 67.
(b) Air duct installation. Four-inch, No. 26 gage, galvanized tubing, with necessary ells, tees, reducing fittings,
supports, and connections, will be installed. Ducts will run with a minimum of bends and approximately as shown on
figure 66. Connections of the air ducts to the dehumidification machine will be made with unions or slip joint connections,
which permit easy removal of the machine for servcing. The air ducting to the various compartments will be as follows:
1. Crew quarters. The dry-air connection for the crew's quarters will be made to the toilet vent. The moist-air
connection will be made to the galley intake vent. A 6-1nch diameter extension approximately 6 feet long will be installed
as shown in figure 66 (revised).
2. Main deckhouse, pilothouse and engineroom. The louvered battery space vent shall be covered with a blank
fabricated from No. 18 gage galvanized sheet metal or 1/2-inch-thick exterior grade plywood, and secured in place by the
use of hookbolts. The blank shall have one Cinch-diameter cutout to recieve the dry-air duct. The dry-air connection may
terminate at the blank or may extend a short distance into the pilothouse.
3. Lazarette. The 2inch-diameter aft hold drain piping between the lazarette and engineroom will be opened to
permit dry-air circulation between engineroom forward area by the way of the removed drain opening m lazarette through
the opened fresh water tanks and water fill pipe as shown m figure 66
(revised).
Change 2
S-2
|
||
|
||
