Description
U.S. Army Technical Manual TM 9-1240-324-34&P for M1 and M1A1 Infinity Aiming Reference Collimator, June 1975
Item Overview
This original U.S. Army technical manual covers direct-support and general-support maintenance for the M1 and M1A1 Infinity Aiming Reference Collimators. Issued as TM 9-1240-324-34&P in June 1975, it also includes repair-parts and special-tools information for these field-artillery optical instruments. This listing is for the technical manual only. It does not include a collimator, tripod, panoramic telescope, weapon, vehicle, power supply, or other equipment.
Identification and Features
The “34&P” suffix identifies this as a combined direct-support and general-support maintenance manual with repair-parts and special-tools lists. The publication covers both the electrically illuminated M1 and the radioactively illuminated M1A1.
- Manual number: TM 9-1240-324-34&P
- Publication date: June 1975
- Subject: M1 and M1A1 Infinity Aiming Reference Collimators
- M1 part number: 8644275
- M1 NSN: 1240-00-066-6065
- M1A1 part number: 10556235
- M1A1 NSN: 1240-00-332-1780
- Official equipment type: Collimator, Infinity Aiming Reference
- Federal Supply Class: 1240, Optical Sighting and Ranging Equipment
- Manual type: Direct-support and general-support maintenance, repair parts, and special tools
- Primary application: Indirect laying of field-artillery weapons
- Associated sighting equipment: Panoramic telescope
- Known weapon-system family: M109 self-propelled howitzer series
- Issuing authority: Headquarters, Department of the Army
- Country of origin: United States
- Item included: Technical manual only
Manual Coverage
This manual provides higher-level guidance for inspecting, troubleshooting, disassembling, repairing, adjusting, assembling, and testing the M1 and M1A1 (radioactive) collimators. It also includes illustrated parts information, official nomenclature, stock and part numbers, maintenance codes, quantities, and special-tool references. Depot-maintenance repair parts are included where required.
How the Collimator Worked
The collimator created an optical reference that appeared to the gunner as though it were located at an infinite distance. The instrument was placed on its tripod a short distance from the artillery piece and aimed toward the weapon’s panoramic telescope. The gunner matched the telescope reticle with the numbered pattern inside the collimator. After the weapon moved from recoil or was given a new deflection, the gunner traversed it until the reticle patterns matched again.
Advantages in Field Use
The infinity aiming reference collimator replaced the need to place two traditional aiming posts far in front of the weapon. It could be positioned close to the gun, often inside a gun position or beneath camouflage. Its illuminated reticle also supported operation at night and during rain, fog, snow, or other poor visibility. The numbered pattern helped crews correct for weapon displacement with greater precision than visually aligning ordinary aiming posts.
Weapon-System Applications
The M1-series collimator was not limited to one artillery model. It supported indirect-fire laying on towed and self-propelled field-artillery weapons equipped with compatible panoramic telescopes. The system was documented with the M109 family of self-propelled howitzers, where it provided a fixed reference point near the vehicle. Towed artillery units could operate the illuminated system from a portable battery supply, while self-propelled weapons could provide electrical power from the vehicle.
Historical Background
The design began as the experimental T6E1 during early 1960s Army testing. It offered a faster and more accurate alternative to the older method of placing striped aiming posts at a distance from each howitzer. The design was later standardized as the M1, followed by the M1A1 with a self-illuminating radioactive reticle. By the time this manual was issued in 1975, M1-series collimators had become established artillery fire-control equipment and continued to support later versions of the M109 self-propelled howitzer.
Condition
Please check the pictures for the general condition of the item. This listing is for one TM 9-1240-324-34&P technical manual only; the M1 or M1A1 collimator, tripod, light controls, power supply, panoramic telescope, weapons, and vehicles are not included.
Ideal For
This specialized manual is useful for collectors, museums, restorers, and researchers studying U.S. Army artillery optics and indirect-fire equipment.
- U.S. Army technical-manual collections
- M1 collimator restoration references
- M1A1 collimator parts research
- M109 self-propelled howitzer displays
- Field-artillery fire-control collections
- Panoramic telescope research
- Cold War artillery exhibits
- Military museum and archival collections
Approx length 8", Approx width 11", Approx height .3", Approx weight .5lbs.
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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