Description
TM 9-3064 Change 3 - 81mm M29 and M29E1 Mortar Cannons, M23 and M23A1 Mounts with Baseplate - April 1965
Item Overview
This April 1965 Change 3 supplement updates TM 9-3064 for the 81mm M29 and M29E1 mortar cannons and M23 and M23A1 mounts with baseplate. It belongs with the original manual issued on August 15, 1957. This publication adds a Vietnam-era update to a reference collection covering American infantry mortars and their supporting equipment.
Identification and Features
The publication number, change designation, and original issue date identify the correct place for this supplement within a technical manual set.
- Publication: TM 9-3064, Change 3
- Change date: April 1965
- Original manual date: August 15, 1957
- Cannons covered: 81mm M29 and M29E1
- Mounts covered: M23 and M23A1 with baseplate
- Manual category: Operation and organizational maintenance
- Publication type: Change supplement for use with the base manual
Function and Manual Contents
Change 3 revises material in the Army's operation and organizational maintenance reference for this mortar family. The parent publication addresses operation, lubrication, and maintenance performed by the unit using the equipment. Read with the base manual, this supplement helps researchers follow the revised guidance available to mortar crews and unit maintenance personnel.
Publication History
The original TM 9-3064 carried the earlier publication number TM 9-260 on its cover. This third change became part of the continuing support record for the 1957 manual. The Army's April 1967 issue of PS Magazine specifically cited TM 9-3064 with three changes, documenting the updated publication's continued use during the Vietnam War period.
Documented End-Item Application
Army equipment data lists the M29E1 cannon with either the M23 or M23A1 mount. In this naming system, cannon refers to the mortar's barrel assembly. The complete ground-mounted weapon combines that assembly with its supporting mount, baseplate, and sighting equipment. These separate component identities are useful when matching period equipment to its documentation.
Equipment History
The M29 began replacing the wartime M1 mortar in U.S. service in 1952. Its lighter construction and greater range advanced the Army's portable infantry fire-support equipment. Grooves around the cannon's exterior reduced weight and helped release heat. The M29E1 remained within this weapon family and could use the established M23-series mounts, linking cannon development with existing support equipment.
M23 and M23A1 Mount Background
The mounts used a bipod with elevating and traversing mechanisms and a spring shock absorber. Their cross-leveling arrangements differed. The M23 used a turnbuckle and clamp, while the M23A1 used a sliding adjustment on its left leg. Cross-leveling kept the mounting system level from side to side. These mechanical differences help collectors identify the two mount versions.
Baseplate Background
The circular baseplate supported the cannon and spread firing forces into the ground. Period Army data describes inner and outer ring assemblies that supported and aligned the barrel. This component formed the lower anchor of the mortar's ground setup. Its construction explains why the baseplate had its own identification and maintenance needs within the complete system.
Weapon-System Background
The M29 family consisted of smoothbore, muzzle-loading weapons designed for high-angle fire. Their curved firing path supported infantry against positions hidden behind terrain or cover. The system could be carried in separate cannon, mount, and baseplate loads. Its infantry role continued the mortar tradition established by earlier weapons such as the French Brandt-derived M1.
History of Use
The M29 family served U.S. and allied forces during the Cold War and Vietnam War. A 1967 field sketch preserved by the Australian War Memorial records an M29 in a South Vietnamese Army bunker at Trieu Phong in Quang Tri Province. The family remained in service through later improvements, before the M252 began replacing it in U.S. service in 1987. This 1965 supplement documents an earlier stage of that long support history.
Ideal For
This supplement adds publication history and technical context to a mortar collection, museum library, or period infantry equipment display.
- Collectors of M29 and M29E1 mortar publications
- Researchers studying M23 and M23A1 mounting equipment
- Museums and military history archives
- Owners of the August 15, 1957 base manual seeking Change 3
- Historians of Cold War and Vietnam-era infantry weapons
Approx length 8", Approx width 10", Approx height .1", Approx weight .15lbs.
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