Electronically timed fuzes

M762, M762A1, and M767 are electronically timed fuzes used with calibers ranging from 75 mm to 155 mm for initiating airbursts at a specified time.

Characteristics:

• Type: Electronic, clock-type fuzes
• Applications: Used with various calibers, including high-explosive (HE), illumination, and smoke projectiles. The M767, in particular, is suitable for fragmentation and HE shells.
• Compatibility: Calibers from 75 mm to 155 mm.

Features:

1. M762/M762A1:

   • These are electronic time fuzes that provide precise detonation at a preset time after firing, commonly used for airburst effects such as illumination and smoke.

2. M767:

   • The M767 fuze also features an additional explosive charge at the base, allowing it to function with high-explosive fragmentation shells. However, it has shown a high rate of failure to detonate in the “PD” (Point Detonating) mode.
   • In practice, some users recommend subtracting 0.2-0.3 seconds from the flight time for airburst above the target, gradually reducing the height of airbursts by adjusting the fuze timing to closely match the projectile’s flight time. However, accurately determining the exact time to impact is challenging, especially considering necessary firing corrections.

These electronically timed fuzes provide greater precision and versatility compared to traditional mechanical fuzes, although their effectiveness can depend on careful timing adjustments, particularly for airburst applications.

• Overall length: 13.4 cm
• Thread length: 9.9 cm
• Overall diameter: 6.1 cm
• Thread diameter: 51 mm
• Weight: 510 g
• Temperature range: -43°C to +63°C
• Self-destruct mechanism: Absent
• Fuze activation: 50 m after leaving the barrel
• Compatible with projectiles: M864, M883, M449, M718, M741, and many others.

The fuze’s scale allows settings from 0.5 to 199.9 seconds.

To operate fuzes with electronic displays, the battery must be activated. If the battery is not activated, the fuze will not function, and the projectile will not detonate upon impact.

To activate the fuze, rotate the setting ring until zeros appear on the display. Next, press the button located on the nose section and rotate the setting ring until dashes appear on the display.

By pressing the button again, four zeros will be displayed. Under the first zero, a triangular index will appear. By turning the setting ring, you can change the zero position to a value in seconds.

The first three values represent time in seconds, and the fourth value represents tenths of a second. The index is moved by pressing the button.

Example: To set the time to 45.1 seconds, the display should show “0451”.

Warning: Heavy rain may lead to premature activation of the fuze during firing.

Do not use the fuze in impact action mode.

After the fuze is activated, its “life” is limited to 15 days.

For the first shot, reduce the time setting by 0.2 seconds to ensure an airburst. Then observe the dispersion pattern and adjust the burst height accordingly.

Note that if you reduce the time, the burst may fall short of the target.

The M782 is a multi-functional artillery fuze, also known as the Multi-Option Artillery Fuze (MOFA), used for high-explosive (HE) 105 mm and 155 mm shells.

Modes of Operation:

The M782 fuze has four modes of operation:

1. Variable Time (VT)
2. Time (TIME)
3. Point Detonating (PD)
4. Delayed Impact (DLY)

Features:

• The M782 contains an electronic timing system that can operate from 0.5 to 199.9 seconds with increments of tenths of a second.
• The fuze is set using an induction key.
• During firing, the fuze’s internal battery is activated, and a microcomputer is initialized.
• The microcomputer loads firing data from the EPROM into one of its registers, verifies the validity of the data, and begins countdown timing.
• The mechanical Safety & Arming (S&A) device is removed after the projectile travels a distance of 400 calibers.

Setting and Activation:

• Electronic Arming: The arming time will depend on the selected mode and the set timing.
• Point Detonating (PD) Mode: If set to PD mode, the detonator activates when the impact switch closes the contacts.
• Delay Mode (DLY): In this mode, detonation is initiated approximately 8 milliseconds after the impact switch closes.
• Time Mode (TIME): The detonator’s primer is activated based on the user-programmed time. If impact occurs before the preset time, the impact switch will close and initiate detonation.
• Variable Time (VT) Mode: In VT mode, the microcomputer enables the proximity sensor relay 4 seconds before the preset time. The microcomputer ignores any signals for the first 200 milliseconds while the signal processor stabilizes. The detonator is activated when the microcomputer receives the fire signal from the signal processor. If impact occurs before the proximity sensor provides a signal, the impact switch will close and initiate detonation.

Characteristics:

• Overall Length: 13.4 cm
• Thread Length: 9.9 cm
• Overall Diameter: 6.1 cm
• Thread Diameter: 51 mm
• Weight: 510 g
• Temperature Range: -43°C to +63°C
• Self-Destruct Mechanism: Absent
• Fuze Activation: 50 m after leaving the barrel
• Compatible with Projectiles: M864, M883, M449, M718, M741, and many others.

The M782 is versatile, capable of supporting multiple detonation functions, including airburst (VT), time-based detonation (TIME), instant impact (PD), and delayed detonation (DLY). It offers a sophisticated electronic control system for precise operation, improving the effectiveness of artillery fire across various mission profiles.

Characteristics

• Overall Length: 12.7 cm
• Thread Length: 12.7 cm
• Overall Diameter: 6.1 cm
• Thread Diameter: 51 mm
• Weight: 454 g
• Setting time range: 2 to 200 seconds
• Temperature Range: -43°C to +63°C
• Self-Destruct Mechanism: Absent
• Fuze Activation: 50 m after leaving the barrel
• Compatible with Projectiles: M864, M883, M449, M718, M741, and many others.

The M782 is versatile, capable of supporting multiple detonation functions, including airburst (VT), time-based detonation (TIME), instant impact (PD), and delayed detonation (DLY). It offers a sophisticated electronic control system for precise operation, improving the effectiveness of artillery fire across various mission profiles.

The fuze is set remotely before launch via an inductive communication line (e.g., using a portable inductive fuze setter M1155, TM 9-1290-210-12&P).

DM 34 is a German multi-purpose fuze for high-explosive (HE) shells, used as a proximity fuze with the capability to detonate at a set height. It can also be used in point-detonating and delayed impact modes with 155 mm and 203 mm caliber shells (fragmentation and high-explosive effects). Additionally, the fuze can be set to initiate at a specific point along the projectile’s trajectory (airburst), which is achieved by setting the built-in timer for a specific duration.

The primary setting for the fuze is the proximity height setting, as it offers the highest effectiveness. The point-detonating and delayed impact modes are used as backup settings in case the proximity height or airburst setting fails to function.

Fuze Type: Proximity height, airburst, fragmentation, and high-explosive action.
Primary Purpose: Proximity height.

• Delay time for impact detonation: 0.01 sec
• Setting: Inductive key and manual setting
• Length: 15.06 cm
• Weight: 900 g

The fuze is set using an inductive key, and manual adjustment is also available for selecting the impact and delayed impact modes.

The fuze is set using an inductive key, which allows adjustment of the burst height above the target.

For setting the fuze to impact or delayed impact action, the time on the built-in timer must be set using the inductive key. The time set should be longer than the projectile’s flight time along the trajectory.

To set the fuze for “airburst” initiation, use the programmer to set the time on the built-in timer that corresponds to the desired position of the projectile along its trajectory.

Manual adjustment allows you to select either impact action or delayed impact action (10 ms). To do this, the plunger located on the fuze body must be moved to position “OV” or “MV,” respectively, using a special wrench or a flathead screwdriver.

If the fuze fails to function in the “proximity height” or “airburst” settings, it will initiate upon impact with an obstacle, either in impact or delayed action mode, depending on the position of the plunger.

For setting the programmer, take the projectile’s flight time from “Kropyva,” and subtract 0.2 seconds (for the first shot). This will roughly correspond to a height of 60 m above the target. Analyze the first burst and adjust the fuze setting time to achieve an airburst at a height of 10-30 m.

DM52A2 is an electronic fuze with an inductive delayed action setting. It is designed for use with 105 mm and 155 mm projectiles and is suitable for all weapon systems, including those with a barrel length of 52 calibers. This fuze is compatible with smoke and illumination munitions, as well as SMArt 155 mm type munitions. The latest variant of the DM52A2 fuze is the L163A1.

The fuze timing can be set inductively from 2 to 199.9 seconds (in 0.1-second increments), either during automatic loading or using a fuze setting device.

The fuze setting is retained permanently but can be reprogrammed at any time before firing.

The fuze complies with STANAG 4187 and provides a safe distance of 150 m for 105 mm systems and 200 m for 155 mm systems. Additionally, it ensures a high level of safety during flight, as its capacitor charges 2 seconds before the set activation time.

• Fuze activation from muzzle: For 155 mm howitzer > 200 m
  Electronic activation: T*-2 sec (T* = programmed flight time)
• Required rotation speed for arming: ≥ 2900 rpm
• Maximum rotation speed: < 25,000 rpm
• Storage temperature range: -54°C to +71°C
• Operating temperature range: -46°C to +63°C
• Visible length: 95.1 mm
• Overall length: 133.4 mm
• Weight: 420 ± 20 g
• Shelf life: 10 years

The fuze timing is set inductively from 2 to 199.9 seconds (in 0.1-second increments) either during automatic loading or using a fuze setting device designed in accordance with STANAG 4369 and AOP 22. The fuze setting is retained permanently but can be reprogrammed at any time before firing. The impact function is available as an option.

The DM74 is a German multi-purpose fuze for high-explosive (HE) shells, used as a proximity fuze capable of detonation at set heights of 3, 6, or 12 meters. It can also function in point-detonating (PD) mode and delayed impact mode with 155 mm and 203 mm HE shells. Additionally, the fuze can be set for initiation at a specific point in the projectile’s trajectory (airburst), which is achieved by setting the built-in timer for a duration from 2 to 199.9 seconds.

The primary setting for the DM74 is proximity height, as this setting offers the highest effectiveness. The impact and delayed impact modes are used as backup options if the proximity height or airburst setting fails to function.

Primary Purpose: Proximity height
Height for Proximity Action: 3, 6, 12 m
Airburst Timing Setting: From 2 to 199.9 seconds
Delay Time for Impact Detonation: 0.01 sec
Length: 151.1 mm
Weight: 395 g
The fuze is set using an inductive key, with manual adjustment also available for selecting impact and delayed impact modes.

DM84, L166 is an electronic, multi-functional artillery fuze with inductive setting, designed and suitable for use with 105 mm and 155 mm high-explosive artillery shells, including extended-range types. The fuze is compatible with artillery systems with barrel lengths of 39, 45, and 52 calibers.

Additionally, it can be used with 120 mm rifled mortars, providing effective use with all charges, including with propellant expulsion.

The fuze body is made of steel to enhance reliability when used with high charges. One of the safety improvements incorporated in the DM84 fuze is its ability to differentiate between different acceleration impulses, such as those generated by a dropped fuze or projectile and those during firing from the barrel. This is achieved through the inclusion of a specially designed battery and a corresponding safety and arming mechanism.

The fuze has the following configurable settings:

• Maximum activation height: 12 m
• Minimum activation height: 6 m
• Time setting: 1 sec – 199.9 sec
• Foliage (tree canopy): 3 m below canopy
• Activation time when set to fragmentation action (SQ): ≤ 250 µs
• Activation time when set to high-explosive action (delay): 16 ms
• Shelf life: 15 years

Fuze Installation:

The fuze can be set automatically by the gun, if the system is equipped for this purpose, or using the DM10 programmer (a standard inductive key). Once set, the fuze setting is retained permanently, but it can be reprogrammed at any time before firing.

The DM84 provides a high level of safety during flight. It is armed approximately 3 seconds before the programmed flight time. The DM84, L166 is also highly resistant to electronic countermeasures.

M8611A1 – a High-Explosive (HE) Electronic Time Fuze (ETF) developed in South Africa. It is equipped with a Point-Detonating Super-Quick (PDSQ) backup impact function, designed to ensure maximum target effectiveness.

Main Characteristics:

• Type of Fuze: Electronic Time Fuze (ETF) with a backup Point-Detonating Super-Quick (PDSQ) function.
• Purpose: Designed for 155 mm artillery shells, optimized for precision firing and engaging various target types.
• Compatibility: Complies with JBMoU standards, enabling use with diverse artillery systems.

The fuze is suitable for artillery systems with barrel lengths of 39, 45, and 52 calibers. Additionally, it can be used with 120 mm rifled mortars and supports shell activation on all charges, including base-bleed ones.
Key Design Features:

1. Activation Device M125A2:
   • Ensures fuze activation at a distance of 50 meters from the gun after firing.
   • Provides a safe arming delay before activation.
2. Electronic Safety Delay:
   • Additional safety layer to minimize the risk of premature activation before reaching the required distance.
3. Time Setting:
   • Adjustment range: 4 to 199.9 seconds, with an increment of 1 second.
   • Offers flexibility in selecting precise detonation time.
4. Program Duration:
   • Minimum operational duration: 30 minutes after activation.
5. Backup Function:
   • PDSQ (Point-Detonating Super-Quick): Ensures instant activation in case of primary function failure.
   • Backup battery is only activated upon projectile rotation and acceleration.

Technical Specifications:

• Maximum Range: Compliant with the parameters of 155 mm caliber shells.
• Length: 151.45 mm
• Diameter: 61.25 mm
• Time Setting Range: From 4 to 199.9 seconds with a 1-second increment.
• Temperature Range: From -40°C to +60°C.
• Programming Time: Up to 30 minutes after activation. The M125A2 activation device ensures a safe arming distance of 50 m from the gun.
• Waterproofing: Resistant to high humidity and rain.

Fuze Installation:

The M8611A1 fuze can be configured autonomously by the gun if equipped with an integrated system, or manually using the DM10 programmer (a standard-purpose inductive key). The fuze settings are retained for up to 30 minutes after programming but can be reprogrammed at any time prior to firing.

In the event of inductive programming failure, the fuze will function as a PDSQ (Point-Detonating Super-Quick), triggering instant detonation upon impact.

Additional Advantages:

• Resistance to vibrations and mechanical impacts during transportation.
• Versatility: compatibility with most artillery platforms.
• Enhanced crew safety due to a multi-level activation system.