Description
Technical Manual (TM 9-1240-247-35) for M102/T172 Telescope October 1960
This Technical Manual TM 9-1240-247-35 covers the M102/T172 Telescope and is dated October 1960.
The publication is a field- and depot-maintenance reference for the articulated gunner’s telescope used in the fire-control system of the M103A1 Heavy Tank.
Historical Significance
The M102 Telescope was part of the Cold War-era fire-control equipment fitted to the M103A1 Heavy Tank, a vehicle armed with the 120 mm Gun M58. It provided the gunner with a direct-fire optical sight for aiming the tank’s main armament.
Within the M103A1 fire-control system, the M102 worked alongside the commander’s M15 stereoscopic range finder, the M14 ballistics computer, and the gunner’s M29 periscope. Together, these instruments supported target ranging, ballistic computation, and precise gun laying.
M103A1 Heavy Tank Application
The M102 was an articulated telescope installed at the gunner’s station. Its optical assembly moved with the weapon’s elevation, allowing the gunner to maintain a direct sight picture while laying the 120 mm gun.
The telescope provided 8-power magnification with a 7.5-degree field of view. Selectable reticles supported the M358 armor-piercing tracer and M356 high-explosive tracer rounds used with the 120 mm Gun M58.
What This Manual Covers
The -35 designation identifies this publication as a field- and depot-maintenance manual. It supports higher-level inspection, troubleshooting, repair, adjustment, servicing, and reassembly of the M102/T172 Telescope beyond routine operator and organizational maintenance.
Its focus is the maintenance of the telescope’s optical, mechanical, and articulated assemblies so the instrument can remain aligned and serviceable within the M103A1 fire-control system.
Key Features
- Official publication number: TM 9-1240-247-35
- Publication date: October 1960
- Equipment covered: M102/T172 Telescope
- Publication scope: field and depot maintenance
- Vehicle application: M103A1 Heavy Tank
- Weapon system context: 120 mm Gun M58
- Equipment function: articulated gunner’s direct-fire telescope
Why This Manual Matters
This manual preserves the Army’s higher-level maintenance guidance for a specialized optical component of the M103A1 fire-control system. It is useful for understanding how the gunner’s primary direct-fire telescope was supported, adjusted, and repaired in service.
The publication also provides important technical context for researchers and restoration specialists studying the M103 heavy-tank family and the optical instruments used with the 120 mm Gun M58.
About This Manual
Published by the Department of the Army in October 1960, TM 9-1240-247-35 is the field- and depot-maintenance manual for the M102/T172 Telescope. It is distinct from TM 9-1240-247-35P, the companion repair-parts and special-tools publication for the M102 Telescope.
Ideal For
This manual is a strong fit for:
- U.S. Army technical-manual collectors
- M103 and M103A1 Heavy Tank researchers
- Military optics and fire-control historians
- Armor museums and reference libraries
- Restoration projects involving M103A1 fire-control equipment
Approx length 8", Approx width 10", Approx height .25", Approx weight .3lbs.
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