Description
U.S. Army Technical Manual TM 9-1290-276-35 for M9 Periscope Drive Mount, August 1961
Item Overview
This vintage U.S. Army technical manual covers field and depot maintenance for the M9 Periscope Drive Mount. Issued as TM 9-1290-276-35 in August 1961, it supported trained personnel responsible for maintaining this mechanical part of the M103A1 heavy tank’s fire-control system. The M9 held and controlled the gunner’s M29 Periscope and was retained with the related sighting equipment on the later M103A2. This listing is for the technical manual only. It does not include a drive mount, periscope, ballistic computer, gun, tank, or other equipment.
Publication Details
The “35” suffix identifies this publication as a field-and-depot maintenance manual. It covered technical work beyond normal crew and organizational care.
- Manual number: TM 9-1290-276-35
- Publication date: August 1961
- Primary subject: M9 Periscope Drive Mount
- Related periscope: M29 Gunner’s Periscope
- Primary application: M103A1 Heavy Tank
- Later application: M103A2 Heavy Tank
- Associated weapon: 120mm M58 Tank Gun
- Manual level: Field and depot maintenance
- Issuing authority: Headquarters, Department of the Army
- Country of origin: United States
- Item included: Technical manual only
Manual Coverage
TM 9-1290-276-35 provides illustrated guidance for inspecting, troubleshooting, disassembling, cleaning, repairing, assembling, adjusting, and testing the M9 drive mount. The equipment included a mounting structure, shield, headrest, input shaft, arm assemblies, and mechanical linkages. Instructions at this level helped maintenance shops restore the mount’s accuracy and dependable movement before returning it to service.
About the M9 Periscope Drive Mount
The M9 was more than a fixed holder for the M29 Periscope. It connected the gunner’s sight to the tank’s ballistic computer and gun-elevation system. Range and ammunition information entered the M14 or M14A1 Ballistics Computer, which calculated the required superelevation for the selected 120mm round. The computer then sent mechanical movement to the M9. The drive mount shifted the periscope’s line of sight so that when the gunner brought the sight back onto the target, the main gun moved to the corrected firing angle.
Associated Fire-Control Equipment
The M9 worked as one part of a larger fire-control installation. The M103A1 used the M29 Periscope and M102 Telescope for the gunner, the M15 Stereoscopic Range Finder for the commander, and the M14 Ballistics Computer. The M103A2 retained the M29 Periscope while adding an improved M102C Telescope and M24 Coincidence Range Finder. These instruments helped the crew measure range, select ammunition data, calculate elevation, and aim the 120mm gun.
M103 Heavy-Tank History
The M103 began as the T43 heavy-tank program during the early Cold War. It was developed to defeat heavily armored Soviet tanks at long range. About 300 tanks were built during 1953 and 1954, but testing led to many improvements before the design was standardized as the M103. The improved M103A1 entered service in 1959 with a better turret layout and fire-control system. Beginning in 1964, selected tanks were rebuilt as the diesel-powered M103A2. All versions carried the powerful rifled 120mm M58 gun and required two loaders to handle its separate-loading ammunition.
History of Use
The August 1961 date places this manual during the M103A1’s active Cold War service. The U.S. Army stationed M103 heavy tanks in West Germany to strengthen NATO forces against possible Soviet armored attacks. The Marine Corps operated most of the M103A1 fleet and later received the improved M103A2. Marine tanks also performed defense and training duties at Guantanamo Bay during the 1960s and early 1970s. The M103 family never fired its main gun in combat and was not deployed to Vietnam. The Army replaced its heavy tanks with the M60 series, while the Marine Corps kept the M103A2 in service until the early 1970s.
Collector and Research Value
This manual documents an uncommon fire-control component from America’s last operational heavy-tank family. It is useful for studying the M103A1 and M103A2, the M29 Periscope, the M14 Ballistics Computer, mechanical superelevation systems, and Cold War tank-maintenance practices. It can also support museum research, vehicle restoration, and military technical-manual collections.
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 specialized manual is well suited for collectors, restorers, researchers, and exhibits covering American heavy tanks and mechanical fire-control equipment.
- U.S. Army technical-manual collections
- M103A1 and M103A2 restoration projects
- M9 Periscope Drive Mount research
- M29 Periscope and M14 Ballistics Computer studies
- 120mm M58 gun-system displays
- Cold War armored-vehicle exhibits
- Museum and archival collections
Approx length 8", Approx width 10", Approx height .2", Approx weight .25lbs.
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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