Description
U.S. Army Technical Manual TM 9-1290-263-34 for M28/T28 and M28A1/T28E1 Azimuth Indicators, October 1959
Item Overview
This U.S. Army technical manual covers higher-level maintenance for the M28/T28 and M28A1/T28E1 Azimuth Indicators. Issued as TM 9-1290-263-34 in October 1959, it supported trained personnel responsible for maintaining these mechanical tank fire-control instruments. This listing is for the technical manual only. It does not include an azimuth indicator, tank, turret, gun, fire-control system, test equipment, or other components.
Publication Details
This manual was prepared to help military maintenance personnel inspect, troubleshoot, repair, adjust, and test the covered azimuth indicators.
- Manual number: TM 9-1290-263-34
- Publication date: October 1959
- Equipment: M28/T28 and M28A1/T28E1 Azimuth Indicators
- Manual type: Direct and general support maintenance
- Equipment class: Mechanical tank fire-control equipment
- Primary historical application: M48-series Patton tanks
- Issuing authority: Headquarters, Department of the Army
- Country of origin: United States
- Item included: Technical manual only
Manual Coverage
The “34” suffix identifies this as a higher-level maintenance publication intended for work beyond normal crew and organizational care. Its subject matter includes inspection, troubleshooting, disassembly, cleaning, repair, reassembly, adjustment, and testing. The manual helps explain how the indicator’s dial, pointers, gearing, housing, drive connections, and related mechanical parts worked together. It is a maintenance manual rather than an operator’s guide or a parts-only publication.
M28 and T28 Designations
The T28 designation identifies the developmental version associated with the standardized M28 Azimuth Indicator. The T28E1 represented an improved development configuration that became the M28A1. Listing both designations helped technicians connect experimental drawings and early records with the standardized equipment. This manual concerns tank azimuth indicators and should not be confused with the unrelated M28 commander’s periscope or other military items that used the same model number.
About the Azimuth Indicator
An azimuth indicator is a mechanical instrument that displays the direction of a tank turret in relation to the vehicle’s hull. Its dial and pointers allowed the gunner to follow large and small changes in turret rotation. This information was especially useful when returning the turret to a known direction, checking fire-control settings, and aiming the main gun during indirect-fire missions.
M48 Patton Weapon-System History
The M48 Patton entered U.S. service during the 1950s as a new generation of medium tank. Early models carried the 90mm M41 tank gun and used a mechanical fire-control system that combined a rangefinder, ballistic computer, ballistic drive, gunner’s sight, elevation quadrant, and azimuth indicator. The T28 and M28 indicators were associated with early M48 fire-control arrangements, while the improved M28A1 appeared in later configurations such as the M48A2.
Later Weapon-System Applications
The M28A1 remained useful after this manual was published. It became part of fire-control arrangements used in the M60 tank family and was later associated with the 105mm M48A5 and the M728 Combat Engineer Vehicle. The M728 used an M60-based chassis and carried a short-barreled 165mm demolition gun. These later applications show how a proven mechanical indicator could remain in service while tank guns, sights, and ballistic equipment continued to change.
History of Use
Tank crews used M28-series indicators to track turret direction and support gun laying. When firing from a concealed position, the azimuth indicator worked with an elevation quadrant and firing data to aim the main gun without a direct view of the target. M48 and M60-family vehicles served during the Cold War, and several variants saw combat during the Vietnam War and later operations. The indicators also supported routine training, fire-control checks, and turret-maintenance work.
Historical Background
The October 1959 date places this manual near the transition from the M48 to the new M60 tank. Mechanical fire-control instruments were still essential even as more advanced rangefinders, stabilization systems, and ballistic computers entered service. The manual records the maintenance methods needed to keep a precise geared indicator accurate under the vibration, shock, dust, and heavy use found inside an armored vehicle.
Collector and Research Value
TM 9-1290-263-34 is a specialized reference for studying early Patton tank fire-control equipment and the development of the M28 Azimuth Indicator. It can help identify components, explain maintenance practices, and support research involving M48 and early M60-series turret interiors. The combined T and M designations also make it useful for studying the change from experimental equipment to standardized Army service.
Condition
This vintage military technical manual may show cover wear, edge wear, folds, yellowing, stains, writing, stamps, punched holes, loose pages, or other signs of age and storage. Printing details and condition may vary between available copies. Please check the pictures for the general condition of the item.
Ideal For
This manual is well suited for collectors, researchers, restorers, and museums interested in Cold War tanks and mechanical fire-control equipment.
- U.S. Army technical-manual collections
- M48 Patton tank research and restoration
- Early M60 tank fire-control research
- M28 and M28A1 azimuth indicator displays
- Cold War armored-vehicle exhibits
- Museum and archival collections
Approx length 8", Approx width 10", Approx height .15", Approx weight .2lbs.
Pictures are stock images of our inventory. Unless otherwise noted, you will not be receiving the exact item shown in the pictures. The pictures are representative of the item’s general condition. The item you receive might be slightly better, or worse, condition than was shown in the pictures.
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