3. Deactivate the fire-extinguishing system.
to all authorized safety practices, requirements, and
procedures for your ship. As a responsible GSM, you
4. Allow the engine to cool. In the event of an
must comply with the guidelines and regulations
emergent y shutdown of a turbine engine when it is not
contained in the current edition of Navy Safety
possible to cool down the engine according to the
Precautions for Forces Afloat, OPNAVINST 5100.19B,
normal shutdown procedures, you must use an
and your ship's EOSS documents.
Let's first look at some of the safety precautions for
maintenance performed inside the engine enclosure.
Next, we will talk about safety precautions for
maintenance performed within the turbine inlet plenum.
To minimize time before personnel can
safely enter the enclosure, you may want to cool
the turbine by motoring. But do not motor for
more than 2 minutes. Also, keep in mind that it
may not be desirable or possible to motor a gas
As you are already aware, the base enclosure
turbine engine, depending on the reason for the
assembly of a GTE consists of a shock-mounted base,
an enclosure, a gas turbine mounting system, intake and
exhaust systems, fire detection and extinguishing
systems, a fuel enclosure heater, a lighting system, and
5. Post a safety observer at the door.
a gas turbine water wash system.
6. Wear the required protective clothing.
The purpose of the engine enclosure is to provide a
7. Open the access doors and make sure they
thermally and acoustically insulated structure for the gas
remain open during all maintenance procedures.
turbine assembly as well as connections for electrical,
fire extinguishing, and air and liquid services. Because
8. Make sure the power sources are secured
the GTE operates inside this enclosure, its inner walls
because of the potentially hazardous voltages.
arc designed to withstand high temperatures. Because
9. Make certain that tools, parts, materials, test
ventilation air is supplied to the enclosure, the
equipment, and other objects are accounted for before
temperature of its outer walls normally will not exceed
personnel enter and after they exit the enclosure.
10. After the maintenance has been completed,
Among the gas turbine ship classes we have
make certain all personnel have exited and are clear of
discussed, the main design differences in the enclosure
the enclosure before the access doors are closed.
are in the access areas to the engine. The FFG-7 class
As you are following the required safety procedures for
ship has doors on either side of the enclosure. The
your ship, use your common sense. Remember, many
DD-963, DDG-993, and CG47 class ships have only
accidents are the result of inattentiveness.
one door with a top hatch and an access ladder. On the
DDG-51 class ships, GTM access is provided by a side
door and a top hatch. Removable side panels are
TURBINE INLET PLENUM
provided next to the door. On the LCAC-class ships, the
enclosure is modular.
In addition to the safety precautions we just
Regardless of the class of ship or the design of the
discussed for maintenance within the engine enclosure,
you must comply with the following special precautions
engine enclosure, you must observe the following
whenever you prepare to perform or supervise
standard safety practices whenever you are preparing to
maintenance within a turbine inlet plenum:
perform or supervise maintenance within an engine
1. Before entering the enclosure, comply with all
1. Comply with all authorized safety regulations
the precautions we described for maintenance within the
and requirements for your ship, including Navy Safety
Precautions for Forces Afloat, OPNAIVINST 5100.19B,
2. Before entering the intake plenum or inlet air
and the EOSS documents for your ship.
duct, remove all articles from your pockets. This means
all personnel should remove all objects from clothing or
2. Tag the gas turbine/diesel generator OUT OF
pockets, including badges, identification tags, and hats.