Description
Technical Manual Change 2 (TM 9-1240-287-34) for M53 Sight Unit May 1986
Technical Manual Change 2 (TM 9-1240-287-34) for M53 Sight Unit – May 1986
Item Overview
This original U.S. Army Change 2 publication updates TM 9-1240-287-34, the direct-support and general-support maintenance manual for the M53 Sight Unit.
Change 2 was issued in May 1986. It applies to the original technical manual dated March 5, 1963 and follows Change 1 from January 1969.
This listing is for the Change 2 update only. It is not the complete March 1963 base manual, Change 1, or a complete updated set. The M53 Sight Unit, mortar, instrument light, carrying case, and tools are not included.
About the Original Manual
TM 9-1240-287-34 provided advanced maintenance instructions for the M53 Sight Unit. It was written for trained support personnel performing work beyond the duties of a mortar crew.
The base manual covered subjects such as:
- Inspection and troubleshooting
- Disassembly and cleaning
- Optical and mechanical repair
- Assembly and adjustment
- Elevation and deflection calibration
- Level-vial inspection
- Final testing
- Preparation for storage or shipment
About the M53 Sight Unit
The M53 combines an M109 Elbow Telescope with an M128 Telescope Mount.
The M109 is a fixed-focus optical instrument with 4x magnification and a 10-degree field of view. It provides the line of sight used to aim a mortar. The M128 mount contains the scales, level vials, knobs, and locking controls used to set elevation and deflection.
The complete sight unit weighs approximately 5.25 lbs. Related lighting equipment allowed the reticle and scales to be viewed during night operations.
Historical Background
The M53 entered service during the Cold War and became a standard sight for several U.S. mortar systems. Documented applications include the 81-mm M29/M29A1 mortar and the 4.2-inch M30 mortar.
These weapons were also installed in armored mortar carriers. The M125 series carried the 81-mm mortar, while the M106 series carried the 4.2-inch M30.
The original manual was issued in 1963, followed by Change 1 in 1969 and Change 2 in 1986. This long update history shows the continued need to support the M53 after more modern equipment entered service.
Identification
- Publication: Change 2
- Manual number: TM 9-1240-287-34
- Equipment: Sight Unit M53
- Change date: May 1986
- Original manual date: March 5, 1963
- Previous update: Change 1, January 1969
- Maintenance level: Direct support and general support
- M53 part number: 8245971
- M53 NSN: 1240-00-856-9452
- Telescope: M109 Elbow Telescope, part number 8588780
- Mount: M128 Telescope Mount, part number 8245970
- Documented applications: M29/M29A1 81-mm mortar and M30 4.2-inch mortar
Collector and Research Value
Later change publications can be difficult to locate after they have been installed in base manuals. This Change 2 update is useful for comparing editions, researching the M53’s long service history, or assembling a complete technical-manual set.
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
- Collectors assembling a complete manual set
Approx length 8", Approx width 10", Approx height .1", Approx weight .1lbs.
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.
Please visit our page about order lead times here: Order Lead Times