Description
Technical Manual (TM 9-1240-287-34) for M53 Sight Unit March 1963
Technical Manual (TM 9-1240-287-34) for M53 Sight Unit – March 1963
Item Overview
This original U.S. Army technical manual covers direct-support and general-support maintenance for the M53 Sight Unit. Issued in March 1963, it was written for trained personnel responsible for advanced inspection, calibration, repair, and rebuilding.
The M53 was a standard mortar sight used to set weapon elevation and deflection. It was associated with systems such as the 81-mm M29/M29A1 mortar and 4.2-inch M30 mortar.
This listing is for the technical manual only. It does not include the M53 Sight Unit, mortar, instrument light, carrying case, tools, or other equipment.
Manual Purpose
TM 9-1240-287-34 provided maintenance instructions beyond the work normally performed by mortar crews and organizational maintenance personnel. Its procedures helped support shops return damaged or inaccurate sight units to service.
The manual covers subjects such as:
- Description and technical data
- Inspection upon receipt
- Troubleshooting
- Disassembly and cleaning
- Inspection of optical and mechanical parts
- Repair and replacement procedures
- Assembly and adjustment
- Deflection and elevation calibration
- Level-vial inspection
- Final testing
- Preparation for storage or shipment
Technical illustrations help identify the sight’s controls, internal assemblies, and repair procedures.
About the M53 Sight Unit
The M53 combined two major components into one complete fire-control instrument:
- M109 Elbow Telescope, part number 8588780
- M128 Telescope Mount, part number 8245970
The M109 is a lightweight, fixed-focus telescope with 4x magnification and a 10-degree field of view. Its reticle provides the optical reference used to aim a mortar in elevation and deflection. The eyepiece can be positioned to the left, right, or upward.
The M128 mount holds the telescope in relation to the mortar’s elevation and azimuth axes. Its scales, knobs, level vials, and locking controls allow the gunner to enter fire-control settings and level the weapon.
The complete M53 Sight Unit weighs approximately 5.25 lbs. Its reticle and scales could be illuminated for night operations with the related instrument-light equipment.
Historical Background
The M53 was introduced during the Cold War as the Army modernized its mortar fire-control equipment. It became a standard sight for the 81-mm M29-series and 4.2-inch M30 mortars.
These mortars were used in ground-mounted and vehicle-mounted roles. Documented applications include the M125-series 81-mm mortar carrier and the M106-series 4.2-inch mortar carrier.
Published in March 1963, this manual dates from the early Vietnam War era. The M53 family remained in military use for decades and was later joined by the improved M53A1.
Identification
- Manual number: TM 9-1240-287-34
- Equipment: Sight Unit M53
- Publication date: March 1963
- Maintenance level: Direct support and general support
- M53 Sight Unit
- Part number: 8245971
- NSN: 1240-00-856-9452
- M109 Elbow Telescope
- Part number: 8588780
- NSN: 1240-00-823-5612
- M128 Telescope Mount
- Part number: 8245970
- NSN: 1240-00-823-5613
- Documented applications: M29/M29A1 81-mm mortar and M30 4.2-inch mortar
Collector and Research Value
This manual is a useful reference for identifying, maintaining, and displaying original M53 components. It also provides historical information for mortar restorations, fire-control collections, and Vietnam-era military exhibits.
Ideal For
- U.S. Army technical-manual collections
- M53 Sight Unit restoration research
- M29 and M29A1 81-mm mortar displays
- M30 4.2-inch mortar displays
- M106 and M125 mortar-carrier research
- Military optics and fire-control archives
Approx length 8", Approx width 10", Approx height .2", 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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