Description
U.S. Army T-159 (M99) Direct-Fire Telescope for M53 and M55 Self-Propelled Artillery
Item Overview
This U.S. Army Telescope T-159 is the developmental version of the standardized M99 direct-fire telescope used with the 155mm M53 Self-Propelled Gun and 8-inch M55 Self-Propelled Howitzer. The 4x elbow-style optical sight gave the gunner a magnified view of visible targets through a compact body suited to the crowded turret. It is an original military optical component for collecting, study, display, or restoration. This listing is for the telescope only, not a complete sighting system.
Identification and Features
Army references identify the T-159 and T-159E1 as development designations in the line standardized as Telescope M99. The telescope has 4x magnification and a 10-degree field of view. Its angled optical path allowed the gunner to look through the eyepiece while the sight remained aligned with the cannon. A raised number on this example appears to read 8206253, but that number has not been confirmed as the complete telescope part number. The separate M101 mount, originally designated T181, and the rubber accordion-style eyeshield do not appear to be included.
- Developmental designation: Telescope T-159
- Standardized designation: Telescope M99
- Optical type: Elbow-type direct-fire telescope
- Magnification: 4x
- Field of view: 10 degrees
- Documented applications: M53 155mm Self-Propelled Gun and M55 8-inch Self-Propelled Howitzer
- Original mount: Telescope Mount M101, formerly T181; not included
- Apparent raised housing number: 8206253; not independently verified
- Eyeshield: Rubber accordion-style eyeshield appears to be missing
- Status: Surplus optical component; operation and optical clarity are not guaranteed
Original Service Function
The T-159 was the gunner's telescope for direct fire against targets that could be seen from the vehicle. Its reticle combined a central boresight cross with range and deflection marks, allowing the gunner to place the correct range and lead on a stationary or moving target. The telescope normally clamped into the M101 mount beside the gun. That mount supplied elevation and azimuth boresight adjustments, a locking system, and a cant-correction level and control. Cant correction kept the reticle upright when the vehicle stood on sloping ground. The telescope was therefore one part of an installed sighting unit and did not provide all adjustment functions by itself.
Weapon Applications
The T-159/M99 served the closely related M53 and M55 tracked artillery vehicles. The M53 carried the long 155mm Gun M46, while the M55 mounted the heavier 8-inch Howitzer M47. Both weapons were installed in the M86 mount inside a large rear turret, and both vehicles used a rear recoil spade when firing. The direct-fire telescope was fitted near the gunner's station, to the right of the recoil-system replenishers. The telescope supported direct engagement of visible point targets; the separate M100 panoramic telescope and other fire-control instruments were used for indirect artillery missions.
Reticle and Configuration Identification
The telescope carries the M53. Army illustrations show a similar pattern for each weapon, but the wording visible through the eyepiece identifies the application.
- M53 configuration: Reticle marked “155 HE M101 SUPER”
- M55 configuration: Reticle marked “8 IN HOW HE M106 / CHARGE 7”
- Shared markings: Central boresight cross, vertical range scale, and horizontal deflection scale
M53 and M55 Historical Background
The M53 was developed after World War II to give heavy artillery the protection and mobility of a fully tracked vehicle. Their automotive design used parts related to the M47 Patton tank, but the engine and drive components were placed at the front so the large turret could sit at the rear. The M53 began as the T97 155mm self-propelled gun. The Army began converting M53 vehicles to the more useful M55 configuration in 1956, while the Marine Corps continued to operate the 155mm M53.
Historical Service Use
These vehicles served during the early Cold War, when the Army wanted armored artillery able to move with tracked combat formations. The M53 provided long-range 155mm fire. Most missions were fired indirectly from map data and observer corrections, but the M99 telescope gave crews a direct-fire option for visible threats or point targets.
Condition
This is an unrestored surplus telescope and may show scratches, worn finish, oxidation, dirt, dents, aged seals, faded markings, or other evidence of service and storage. The rubber accordion eyeshield appears to be missing, and the separate M101/T181 telescope mount is not included. Lens clarity, reticle condition, internal illumination, adjustment, completeness, and optical alignment have not been tested or guaranteed. This listing includes one T-159/M99 telescope only; the mount, weapon, vehicle, tools, covers, and other accessories are not included unless specifically stated. Please check the pictures for the general condition of the item.
Ideal For
This telescope is a strong display and restoration component for collections focused on Cold War artillery, armored vehicles, military optics, and Vietnam-era equipment. Its link to both the M53 and M55 makes it useful for showing how one fire-control component supported two related heavy artillery systems.
- M53 155mm Self-Propelled Gun restorations
- Cold War U.S. Army collections
- Vietnam War artillery exhibits
- Military optical-instrument collections
- Museum and educational displays
Approx length 29", Approx width 18", Approx height 8", Approx weight 38lbs.
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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