Description
U.S. Army Technical Manual TM 9-1290-322-35 for M15/T23E2 Fire Control Quadrant, December 1962
Item Overview
This U.S. Army technical manual covers field and depot maintenance for the M15 Elevation Fire Control Quadrant, formerly designated T23E2. Issued as TM 9-1290-322-35 in December 1962, it supported trained personnel responsible for maintaining this precision artillery instrument. This listing is for the technical manual only. It does not include an M15 quadrant, sight, gun, howitzer, vehicle, or other equipment.
Publication Details
This early Cold War manual was published as several new self-propelled artillery systems were entering Army service.
- Manual number: TM 9-1290-322-35
- Publication date: December 1962
- Equipment: M15 Elevation Fire Control Quadrant
- Development designation: T23E2
- Federal Stock Number: 1290-896-2236
- Later National Stock Number: 1290-00-896-2236
- Army part number: 8247683
- 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
The “35” suffix identifies this as a higher-level maintenance publication for work beyond routine crew and organizational care. Manuals at this level supported inspection, troubleshooting, disassembly, cleaning, repair, reassembly, adjustment, and final testing. The subject matter is useful for understanding the quadrant’s housing, counters, knobs, gear system, level vials, lighting parts, and alignment requirements.
About the M15/T23E2 Quadrant
The T23E2 designation identifies the instrument’s development-stage configuration before it was standardized as the M15. The quadrant was mounted to the weapon system and measured the gun tube’s elevation in mils. An elevation counter displayed the setting, while level vials helped the crew position the instrument correctly. A cross-level mechanism corrected for a vehicle or gun carriage that was leaning to one side, and a separate correction control allowed small changes to firing data. These features helped the crew lay the weapon at the elevation ordered by the fire-direction center.
Documented Weapon Applications
The M15 became a common elevation instrument on several American self-propelled artillery systems introduced during the early 1960s. Applications documented in military publications include the following vehicles.
- M108: 105mm self-propelled howitzer
- M109 series: 155mm self-propelled howitzer
- M107: 175mm self-propelled gun
- M110 series: 8-inch self-propelled howitzer
Self-Propelled Artillery History
The Army developed these tracked weapons to give artillery units better mobility during the Cold War. The M108 and M109 shared a related chassis, but the M109’s more powerful 155mm weapon made it the more successful design. The M107 and M110 formed another related family, with the M107 carrying a long-range 175mm gun and the M110 carrying a heavy 8-inch howitzer. The M15 quadrant could be used with both direct- and indirect-fire procedures by helping crews set and check gun elevation.
History of Use
The December 1962 date places this manual at the beginning of service for these new artillery vehicles. The M108, M109, M107, and M110 all served during the Vietnam War. The M108 was withdrawn from regular U.S. service after a shorter career, while the M109 developed into one of the longest-serving American self-propelled howitzer families. The M107 and M110 provided heavy, long-range fire support, and improved M110 models remained in service for many years. Later Army publications continued to list the M15 quadrant for M109 and M110-series weapons.
Collector and Research Value
TM 9-1290-322-35 is a useful reference for collectors, restorers, museums, and historians studying early Cold War artillery. Its T23E2 designation also makes it valuable for research into the development and standardization of Army fire-control equipment.
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 collections, restoration projects, research, and displays covering American artillery and mechanical fire-control equipment.
- U.S. Army technical-manual collections
- M15 and T23E2 quadrant research
- M108 and M109 howitzer restoration
- M107 and M110 artillery displays
- Vietnam War artillery collections
- Museum and archival research
Approx length 8", Approx width 10", Approx height .25", Approx weight .4lbs.
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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