Figure 4-9.—Sealing strip anchor installation.
cylinders. They, in turn, drive the shuttle. Component
parts of each piston assembly are the steam piston, the
barrel, the connector and the strip guide, the piston
guide, and the tapered spear (see fig. 4-6).
The barrel serves as the chassis for the other
components of the assembly. The piston is bolted to the
aft end of the barrel; the piston rings installed on the
piston seal the space between the piston and the
cylinder wall. The cylinder cover segmented seal
assembly acts as an extension of the piston into and
through the cylinder slot. This seal assembly consists of
a housing, three upper seal segments, and six lower seal
segments. The upper seal segments press against the
cylinder covers, and the lower seal segments press
against the sides of the cylinder slot to prevent the loss
of steam pressure from behind the steam pistons as the
piston assemblies move through the cylinders during the
power stroke. The connector and the strip guide are
bolted to the top of the barrel (fig. 4-6). The connector
lifts the sealing strip off its seat to permit passage of
the shuttle assembly along the cylinder. The strip guide
returns the sealing strip to its seat after the connector
passes under it, minimizing loss of steam pressure as
the piston assembly advances through the power stroke.
In addition (see figs. 4-6 and 4-10), the connector has
interlocking “dogs,” which couple with matching
“dogs” on the shuttle assembly to effect the connection
between the connectors and the shuttle assembly.
The tapered spear and bronze piston guide are
bolted to the forward end of the barrel. The piston
guide acts as a bearing surface for the piston assembly
and keeps it centered with respect to the cylinder walls.
The tapered spear works in conjunction with the
water-brake cylinder assemblies to stop the piston
assemblies and shuttle at the end of the power stroke.
Shuttle
The shuttle (fig. 4-10) carries the forward motion of
the pistons to the aircraft by means of a launch bar
attached to the aircraft nose gear and connected to the
nose gear launch shuttle spreader. The shuttle and the
piston assemblies are connected by the meshing of
interlocking “dogs” of the piston assembly connectors
and the shuttle frame (fig. 4-10).
The shuttle is essentially a frame mounted on
rollers. Two pairs of rollers fitted with roller bearings
are installed on hubs mounted at each end of the shuttle
frame. The shuttle is installed in a track between and
above the launching engine cylinders. The trough
covers form the shuttle track, which supports and
guides the shuttle.
The bearings of the rollers are lubricated through
fittings, which are accessible through the slot in the
shuttle track. The shuttle blade is part of the shuttle
frame and is the only part that protrudes above the
4-9
