conducted only at a maintenance facility where
SECURING TENDER RECEIVING
p r o p e r industrial assistance is available.
OPERATIONS.--When the tended ship has
Furthermore, no work procedure or maintenance
transferred its sewage, close the tender receiving
should be performed without proper equipment,
station stop valves (R), and disconnect sewage hoses
safety precautions, and supervision.
from the receiving stations following previously
discussed procedures.
Work Procedures
Advance facility arrangements should be made
CAUTION
for a qualified gas-free engineer and for the design
and installation of the necessary temporary
Before any hose is disconnected, open
ventilation. These arrangements should be made
all valves in the lines to the CHT tanks on
with t h e production engineering, gas-free
the tended ships to depressurize the lines.
engineering, and industrial hygiene departments, or
Also assure that all pump selector switches
similar operating units. Before opening the tank,
on the tended ships are in the OFF
these specialists should ensure that the pump room
position.
is properly ventilated and under positive pressure.
T h e following procedures should then be
followed:
SUBMARINE SEWAGE TRANSFER TO
1. Divert all drains overboard.
TENDER.-- Submarine transfer procedures are
similar to surface ship transfer procedures. The
2. Isolate all heads, fountains, or drains located
exception is that the receiving station stop valves
below the level of the overflow discharge.
(R) (fig. 17-5) are opened and remain open only
d u r i n g receiving. Submarines must obtain
3. Ensure that the valve in the overflow
discharge line is open.
sewage. When receiving operations have been
secured, the tender gives a complete air blow of the
4. Operate the aeration system, if available.
hose and piping to minimize hose spillage during
disconnect.
5. Pump out the tank completely. When pump
suction is lost, turn off the pump.
CAUTION
6. Open the tank washdown valve and fill the
tank until water comes from the overflow overboard
If the high-level alarm sounds on the
discharge. Secure the washdown system.
tender while it is receiving sewage from
the submarine, notify the submarine to
7. Repeat steps 5 and 6.
stop transfer.
Investigate and take
corrective action before resuming transfer.
8. Repeat step 5.
Ensure that sewage transfer hoses are not
pressurized before they are disconnected.
9. Secure the air supply.
CHT TANK WORK PROCEDURES
AND MAINTENANCE
WARNING
The hygienic practices discussed under sewage
TOXIC HAZARD: Toxic gases may
transfer operations must be observed by all
exist in the tank and associated piping in
personnel who perform maintenance or troubleshoot
and adjacent to the pump room. Do not
the CHT system.
open the system until it has been certified
gas-free.
CHT tanks should be cleaned and inspected at
least every 3 years. This inspection should be
17-17