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Basic Fire Control Mechanisms Maintenance, OP 1140A, 1946, has maintenance procedures for the mechanical computing elements used in U.S. Navy fire control systems. These components are the building blocks of some of the most successful analog mechanical computers ever built.

This online version of the manual is provided in PDF format. This means that the files are large and you consider saving them to your local hard disk for repeated viewings to avoid long downloads.

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Please report any typos, or particularly annoying layout issues with the Mail Feedback Form for correction.

Richard Pekelney

OP 1140 A
Basic Fire Control Mechanisms Maintenance
A Bureau of Ordnance Publication


Table of Contents
Manufacturer's Practices
Tools and Materials
Basic Repair Operations
Pages 1-79
op1140a-1.pdf (11.7 MB PDF)
Non-Computing Mechanisms
Shaft Lines
Shaft Line Devices
Dial Assemblies and Counters
The Intermittent Drive
The Shock Absorber
Pages 80-173
op1140a-2.pdf (13.6 MB PDF)
Computing Mechanisms
Bevel Gear Differential
Jewel Differential
Screw Type Multiplier
Rack Type Multiplier
Sector Type Multiplier
Cam Type Multiplier
Cam Type Component Solver
Screw Type Component Solver
Pages 174-273
op1140a-3.pdf (16.7 MB PDF)
Computing Mechanisms Continued
Vector Solver
Disk Integrators
Component Integrators
Ballistic Computer
Computing Cams
Pages 274-379
op1140a-4.pdf (46.4 MB PDF)
Electromechanical Mechanisms
Servo Motor
Synchro Receivers
Pages 380-489
op1140a-5.pdf (17.5 MB PDF)
Electromechanical Mechanisms Continued
Time Motor Regulator
Time of Flight Mechanism
Solenoid Lock and Clutch
Solenoid Signal
Pages 490-562
op1140a-6.pdf (11.2 MB PDF)
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