What provides a means of measuring launch
What is the purpose of the keeper valve?
motion of the pistons to the aircraft?
What system provides a means of lubricating
the launching engine cylinders?
The bridle tensioning system full-aft limit
switch is part of what catapult circuit?
The auxiliary tank of the hydraulic system has
a capacity of how many gallons?
What is the function of the retraction engine
and drive system?
The controls for the ICCS are divided
between what panels?
readiness of the catapult to the launching
LEARNING OBJECTIVE: Describe the
operation of a steam catapult.
A steam fill-valve system controls the amount of
steam from the ship's boilers to the wet-steam
accumulator. Steam from the steam accumulator is then
released into the launching engine cylinders through
the launch valve (the amount of steam used is varied by
a capacity selector valve [CSV] assembly that controls
the launch valve opening rate).
This surge of steam acts on a set of steam pistons
inside the launching engine cylinders. These pistons are
connected to a shuttle that is attached to an aircraft. The
force of the steam being released from the steam
accumulator pushes the pistons forward, towing the
shuttle and aircraft at an increasing speed until aircraft
take-off is accomplished.
The shuttle and steam pistons are stopped at the end
of their "power stroke" as a tapered spear (fig. 4-68)
enters a set of water-filled cylinders, forcing the water
to be "metered" out of the cylinders as the tapered spear
moves into them.
After the shuttle and pistons have been stopped, a
grab is advanced forward along the catapult trough
covers by means of the retraction engine, and attaches
to the shuttle assembly. The retraction engine is then
reversed and returns the grab, shuttle, and piston
assembly to the battery position in preparation for the
next aircraft launch.
A integrated catapult control station (ICCS),
central charging panel (CCP), main control console,
control/charging panel, and water brake panel are used
in conjunction to direct and integrate the catapult
electrical and hydraulic systems functions and to
control the sequence of operations through a normal
catapult launching cycle.
Preliminary functional tests are performed by all
operating personnel. These tests consist of at least two
no-load launchings, during which the control system is
operated through its complete cycle. The functioning of
as many component parts of the catapult as possible
should be observed by personnel at the various stations
1. SHUTTLE IN BATTERY POSITION
2. AIRCRAFT ATTACHED TO SHUTTLE AND HOLDBACK UNIT
3. TENSIONER AND GRAB EXERT FORWARD PRESSURE ON
SHUTTLE FOR TENSIONING. GRAB AND SHUTTLE UNLOCK
1. HOLDBACK UNIT RELEASES
2. SHUTTLE TOWS AIRCRAFT FORWARD
PISTONS AND SHUTTLE HALTED
BY WATER BRAKES
GRAB ADVANCES AND LATCHES TO SHUTTLE
GRAB RETRACTS SHUTTLE TO BATTERY POSITION
AIRCRAFT PREPARED FOR LAUNCH
Figure 4-68.Catapult operation.