CHAPTER 4
STEAM CATAPULTS
Steam catapults are steam powered and direct drive.
In this chapter we describe the basic design of the
steam catapult, while presenting some of the major
differences in the various modifications of the steam
catapult.
When you complete this chapter you should be able
to do the following:
State the functions of the various catapult
systems and their controls.
Describe the operation of the integrated catapult
control station (ICCS) monitor control console.
• Explain the operation and functions of the
C-13/C-13-1 hydraulic charging panel.
• Describe procedures for operating and
monitoring the linear and rotary retraction engines.
STEAM-POWERED CATAPULTS
Steam is the principal source of energy and is
supplied to the catapults by the ship’s boilers, The
steam is drawn from the ship’s boilers to the catapult
steam receivers or accumulator, where it is stored at the
desired pressure. From the receivers/accumulator, it is
directed to the launching valves, and provides the
energy to launch aircraft. The most significant
differences between the various types of steam catapults
are the length and capacity. See table 4-1 for the
differences.
DESCRIPTION OF OPERATION
A steam fill-valve system controls the amount of
steam from the ship’s boilers to either the dry-steam
receivers or the wet-steam accumulator, depending on
your ship’s catapult steam system. Steam from the
steam receivers/accumulator is then released into the
launching engine cylinders through a set of launch
valves (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 (see
fig. 4-1). The force of the steam being released from
the steam receivers/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 (figs. 4-1 and
4-2) 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.
Table 4-1.—Steam Catapult Data
4-1
