pzgr40
Well-Known Member
Cutaway models of the BLU-91/B anti-tank mine and the BLU-92/B anti-personnel mine.
Both the BLU-91/B and the BLU-92/B are air delivered, free fall, Bidirectional mines, delivered by CBU’s under aircraft. The mines are meant for rapid, large scale mining and temporary area denial, with the potential to be delivered deep behind enemy lines. It will disrupt and disorganize troops, denies usage of key area’s and disrupt mine clearing operations.
The mine belongs to a family of mines that have the same basic mine mechanism, but slight differences due to the way of delivery. These are:
-The M76 AT scaterable mine and the M77 AP mine , as used in the M-131 MOPMS (Modular Pack Mine System)
-The 155mm M718 projectile , containing 9 pcs of Long delay self-destruct M70 AT mines. The 155mm M741 projectile , containing 9 pcs of short delay self-destruct M73 AT mines.
-The GEMSS (Ground Emplacement Mine Scattering System) and it’s follow up the M-128 Frisbee slinger, as well as the Volcano system which use the M74 and M75 mines.
-The Gator sytem used by the US airforce and US navy, where the mine has an aero ballistic adapter to make it suitable for air delivery.
Due to the different launching conditions there are some differences in arming time.
The US air force used the mines in the CBU-89/B (Cluster Bomb Unit) containing 72 anti-tank and 22 anti-personnel mines. The CBU housing is known as the SUU-64 Tactical munitions dispenser, which uses the FZU-39 Proximity sensor.
The US navy uses the CBU-78/B , containing 45 anti-tank and 15 anti-personnel mines. It uses the same dispenser as the Rockeye.
As dispensers are loaded with both mine types one should consider that if one type of these mines is found the presence of the other type can be suspected.
Before taking off, the CBU self-destruct time is programmed by rotating a dial on the dispenser to one of three numbered positions.
-T1 ; 3,2 to 4 hours.
-T2 ; 32,8 to 40 hours.
-T3 ; 228 to 360 hours.
If the self-destruct timer does not function, the mines will become dysfunctional after 40 days when the battery’s are fully discharged.
During the first gulf war the Us Air Force deployed 1.105 CBU-89’s, mainly to hamper the movement of the scud missile launchers.
After this war EOD personnel found out that the dud rate was between 0,5 and 2% for the BLU-91 and between 6 to 21% for the BLU-92B. It was also noted that mines detonated spontaneously, which was speculated to be caused by the extreme heat of the Kuwait desert.
Description and functioning of the BLU-91/B anti-tank mine:
The mine resembles a rectangular box 143x127x69mm, with a cylindrical part (120mm dia.) in the middle which is the mine itself. The square PVC box which is placed around it forms the aero ballistic adapter which retards the mine when falling , and disperses the mines due to the Fletner rotor effect. This effect is caused by two opposite sides of the adapter which have a vane that scoops air while travelling through the air, forcing the mine to rotate. After landing, the aero ballistic adapter may break away from the mine, leaving a cylinder only. When stacked, a bore rider safety plate (P01-1) -on one side of the mine- pushes the spring loaded bore rider safety pin (P01/P03 -2) inward, keeping the mine in an unarmed position.
The colour of the mine is olive green overall.
The mine is comprised of two mirrored ballistic discs (P01-3) (EFP’s / SFF), functioning according to the Misznay-Shardin effect). In the centre the safety and arming mechanism is placed (P03). In the hollow space of one of the ballistic discs, the cast in electronics, battery’s, metal detector / magnetic sensor (P02-4) and clearing charge are placed (P01-5); the opposite side houses a white PVC spacer (P01-6), housing a clearing charge only (P07 / P01-5). The main explosive charge is a 590 grams RDX charge (P01-7) which is placed between the two ballistic discs, with a 14 grams PBXN-5 ring shaped booster charge (P01-8) around the S&A unit (P03 / P04).
The mines receive an electric arming and self destruct pulse signal at the opening of the dispenser. This pulse is induced to the MCS (Magnetic Coupling System ( P01-9), simultaneously initiating the battery primer, opening the self destruct fusible links, mechanically locks out the bore rider safety mechanism (P01-2), and opening a short circuit on a firing capacitator (condensator). When initiated, the battery primer activates two Lithium battery cells (P05-10), providing a nominal 6,4 volts.
Subsequent battery power starts electronic timing circuits in the electronics assembly (P01-11) that that controls arming and -one of three; T1,T2,T3- self destruct times.
When packed in the CBU, the mines are stacked, the bore rider safety plate (P01-1) kept in locked position by the mine below and above.
Upon release from the CBU, the bore rider safety plate is blown off by the air stream, allowing the spring loaded bore rider pin (P01-2) to rise and release one of two restraints (P03-12) in the safety and arming mechanism, enabling the mine to complete it’s arming cycle after the mine has come to rest on the ground.
Approximately 105 seconds after the initial arming pulse, a micro piston actuator (P04-13) fires, breaking the slider release pin (P04-14) and removing the slider release (P04-15) away from the slider, allowing the spring loaded slider (P04-16) to move into explosive alignment.
Ten seconds later, a firing circuit charges the firing capacitator, and electrically places it in line with the magnetic sensor (magnetometer / sort of metal detector). The mine is now armed.
The mine can be activated in several ways:
-When the magnetometer senses a valid target of proper signature using the magnetometer and digital circuitry.
-anti disturbance; when the magnetometer senses detection of ambient field change by movement. of the mine.
-The self destruct time setting (T1,T2,T3) expires.
-The electronic timer circuit malfunctions.
Upon activation the firing circuit initiates the M100 detonator (P04-17) through selector switch to the transfer lead (P04-18) and mild detonation fuze assembly (P04-19) which detonates the clearing charge (P07 / P02-5) on the upside of the mine. The selector switch is a rectangular machined surface in the S&A unit with two holes, a top and a bottom one. An interrupter disc (P03-P04-20) , locking off one of both holes is placed in a rectangular frame called the interrupter retainer (P03-P04-21), placed behind the holes. After the mine has landed, the disc falls down, always locking off the lower of both holes, ensuring it is always the top cover that is blown off (P08).
The millisecond delay detonator (P04-22) is initiated by the M100 micro detonator (P04-17) , which ignites the centre lead (P04-23) and the four main charge output leads (P03/P04-24) in the S&A mechanism. This ignites the ring shaped PBXN-5 charge around the S&A unit (P01-8), which ignites the main charge, throwing away both discs (P01-3), according to the Misznay-Shardin effect.
Penetration of the mine is stated to be 61mm (2,4 inch) of armour steel plate.
The mine weighs 1,91 Kg (4,20 pounds).
An interesting you tube movie showing the BLU-91-B AT mine in use can be found here: https://www.youtube.com/watch?v=OBqdtq-6gcw
Description and functioning of the BLU-92/B anti-personnel mine:
The BLU-92B closely resembles the BLU-91B anti tank mine in outer appearance. It has the same dimensions as the BLU-91-B. The easiest observable difference are the four oval shaped ports (P10-25) -at 90 degrees each- in the top and base plate of the cylindrical part of the mine, which house the eight trip wire assembly’s . A sheet metal top and base plate (P10-26) locks up all inner parts and is connected with the scored (P10-27) steel fragmentation sleeve by means of a rolled seam.
The BLU-92B is an air delivered , free fall, bidirectional , electromechanically armed anti personel mine. It is detonated by means of 12 meters long tripwires or self destruct (T1,T2,T3) . Some mines have an additional anti disturbance switch, which detonates the mine if moved.
The mine is constructed as follows:
The centre of the mine houses the same S&A mechanism (P03,P04) as the BLU-91B . Around it, two mirrored black PVC tripwire assemblies are placed, (P09-, P11-28) each housing four tripwire assembly’s at 90 degrees each. Between the two assemblies a cast in electronics disc is placed (P11-29), housing the self destruct timer mechanism, the additional anti disturbance fuze (with some mines) and the firing circuit electronics. One of both tripwire sensor assembly’s houses the two lithium battery cells (P09/P10-30) delivering 6,4 volts. Below the battery, the MCS (Magnetic Coupling Sensor) assembly (P09/P10-31) is placed. Four detonators (P09-32), -at 90 degrees each- are placed in the explosive charge (P09-35), each connected to the S&A device with a connection pipe (P09-33) filled with explosives. Around the black PVC tripwire assemblies an aluminium ring shaped container (P09-34) is placed housing the 400 grams (14,1 Oz) Composition B4 explosive charge (P09-35).
Around the explosive charge the ring shaped scored steel fragmentation sleeve (P10-27) is placed. The mine is completed with the aero ballistic adapter. After landing, the aero ballistic adapter may break away from the mine, leaving a cylinder only.
The mines receive an electric arming and self destruct pulse signal at the opening of the dispenser. This pulse is induced to the MCS (P09/P10-31) (Magnetic Coupling System), simultaneously initiating the battery primer, opening the self destruct fusible links, mechanically locks out a bore rider safety mechanism, and opens a short circuit on a firing capacitator (condensator). When initiated, the battery (P10-30) primer activates two Lithium battery cells, providing the 6,4 volts.
Subsequent battery power starts electronic timing circuits in the electronics assembly, that controls arming and -one of three; (T1,T2,T3) self destruct times.
When packed in the CBU, the mines are stacked, the bore rider safety plate (P09-36) kept in locked position by the mine below and above.
Upon release from the CBU, the bore rider safety plate is blown off by the air stream, allowing the spring loaded bore rider pin (P03-2) to rise and release one of two restraints (P03-12) in the safety and arming mechanism, enabling the mine to complete its arming cycle after the mine has come to rest on the ground.
Approximately 105 seconds after the initial arming pulse, a micro piston actuator fires (P04-13) , breaking the slider release pin (P04-14) and removing the slider release (P04-15) away from the slider , allowing the spring loaded slider (P04-16) to move into explosive alignment.
Simultaneously, the electronics fires the pressure cartridge which releases the restraints on the tripwire springs. The pressure cartridge is a bidirectional gravity switch that senses which tripwire assembly disc is facing upward. Each tripline sensor is series connected to an electronic firing circuit.
Each tripwire assembly is a pressed aluminium cup (P10-37), housing a strong spring (P10-38). A cup with four hooks (P10-39) is placed in this cup pushing the spring inward tight. A spool (P10-40) housing 12 mtrs of fine green wire is riveted to the cup with the hooks. The lower portion of the spool is connected to the small ejection (P10-41) charge. The ejection charge is meant more to release the trip wire spool from it’s impact safe position than to launch the tripwire, which is done by the spring.
The wire is 12 mtrs long, so when fully used the four wires (at 90 degrees each) form a square of 17x17 mtrs in which one will encounter a tripwire.
When the tripwire is pulled with a force between 4,8 and 14 ounces (136 and 379 grams) , a breakwire in the bottom of the tripwire cup breaks, activating the detonator in the S&A mechanism.
Regards, DJH
Sources:
http://fas.org/man/dod-101/sys/land/fascam.htm
-TM U.S. Landmine APERS, BLU-92/B (Gator).
-TM U.S. Landmine AT/AV, BLU-91/B (Gator).
Both the BLU-91/B and the BLU-92/B are air delivered, free fall, Bidirectional mines, delivered by CBU’s under aircraft. The mines are meant for rapid, large scale mining and temporary area denial, with the potential to be delivered deep behind enemy lines. It will disrupt and disorganize troops, denies usage of key area’s and disrupt mine clearing operations.
The mine belongs to a family of mines that have the same basic mine mechanism, but slight differences due to the way of delivery. These are:
-The M76 AT scaterable mine and the M77 AP mine , as used in the M-131 MOPMS (Modular Pack Mine System)
-The 155mm M718 projectile , containing 9 pcs of Long delay self-destruct M70 AT mines. The 155mm M741 projectile , containing 9 pcs of short delay self-destruct M73 AT mines.
-The GEMSS (Ground Emplacement Mine Scattering System) and it’s follow up the M-128 Frisbee slinger, as well as the Volcano system which use the M74 and M75 mines.
-The Gator sytem used by the US airforce and US navy, where the mine has an aero ballistic adapter to make it suitable for air delivery.
Due to the different launching conditions there are some differences in arming time.
The US air force used the mines in the CBU-89/B (Cluster Bomb Unit) containing 72 anti-tank and 22 anti-personnel mines. The CBU housing is known as the SUU-64 Tactical munitions dispenser, which uses the FZU-39 Proximity sensor.
The US navy uses the CBU-78/B , containing 45 anti-tank and 15 anti-personnel mines. It uses the same dispenser as the Rockeye.
As dispensers are loaded with both mine types one should consider that if one type of these mines is found the presence of the other type can be suspected.
Before taking off, the CBU self-destruct time is programmed by rotating a dial on the dispenser to one of three numbered positions.
-T1 ; 3,2 to 4 hours.
-T2 ; 32,8 to 40 hours.
-T3 ; 228 to 360 hours.
If the self-destruct timer does not function, the mines will become dysfunctional after 40 days when the battery’s are fully discharged.
During the first gulf war the Us Air Force deployed 1.105 CBU-89’s, mainly to hamper the movement of the scud missile launchers.
After this war EOD personnel found out that the dud rate was between 0,5 and 2% for the BLU-91 and between 6 to 21% for the BLU-92B. It was also noted that mines detonated spontaneously, which was speculated to be caused by the extreme heat of the Kuwait desert.
Description and functioning of the BLU-91/B anti-tank mine:
The mine resembles a rectangular box 143x127x69mm, with a cylindrical part (120mm dia.) in the middle which is the mine itself. The square PVC box which is placed around it forms the aero ballistic adapter which retards the mine when falling , and disperses the mines due to the Fletner rotor effect. This effect is caused by two opposite sides of the adapter which have a vane that scoops air while travelling through the air, forcing the mine to rotate. After landing, the aero ballistic adapter may break away from the mine, leaving a cylinder only. When stacked, a bore rider safety plate (P01-1) -on one side of the mine- pushes the spring loaded bore rider safety pin (P01/P03 -2) inward, keeping the mine in an unarmed position.
The colour of the mine is olive green overall.
The mine is comprised of two mirrored ballistic discs (P01-3) (EFP’s / SFF), functioning according to the Misznay-Shardin effect). In the centre the safety and arming mechanism is placed (P03). In the hollow space of one of the ballistic discs, the cast in electronics, battery’s, metal detector / magnetic sensor (P02-4) and clearing charge are placed (P01-5); the opposite side houses a white PVC spacer (P01-6), housing a clearing charge only (P07 / P01-5). The main explosive charge is a 590 grams RDX charge (P01-7) which is placed between the two ballistic discs, with a 14 grams PBXN-5 ring shaped booster charge (P01-8) around the S&A unit (P03 / P04).
The mines receive an electric arming and self destruct pulse signal at the opening of the dispenser. This pulse is induced to the MCS (Magnetic Coupling System ( P01-9), simultaneously initiating the battery primer, opening the self destruct fusible links, mechanically locks out the bore rider safety mechanism (P01-2), and opening a short circuit on a firing capacitator (condensator). When initiated, the battery primer activates two Lithium battery cells (P05-10), providing a nominal 6,4 volts.
Subsequent battery power starts electronic timing circuits in the electronics assembly (P01-11) that that controls arming and -one of three; T1,T2,T3- self destruct times.
When packed in the CBU, the mines are stacked, the bore rider safety plate (P01-1) kept in locked position by the mine below and above.
Upon release from the CBU, the bore rider safety plate is blown off by the air stream, allowing the spring loaded bore rider pin (P01-2) to rise and release one of two restraints (P03-12) in the safety and arming mechanism, enabling the mine to complete it’s arming cycle after the mine has come to rest on the ground.
Approximately 105 seconds after the initial arming pulse, a micro piston actuator (P04-13) fires, breaking the slider release pin (P04-14) and removing the slider release (P04-15) away from the slider, allowing the spring loaded slider (P04-16) to move into explosive alignment.
Ten seconds later, a firing circuit charges the firing capacitator, and electrically places it in line with the magnetic sensor (magnetometer / sort of metal detector). The mine is now armed.
The mine can be activated in several ways:
-When the magnetometer senses a valid target of proper signature using the magnetometer and digital circuitry.
-anti disturbance; when the magnetometer senses detection of ambient field change by movement. of the mine.
-The self destruct time setting (T1,T2,T3) expires.
-The electronic timer circuit malfunctions.
Upon activation the firing circuit initiates the M100 detonator (P04-17) through selector switch to the transfer lead (P04-18) and mild detonation fuze assembly (P04-19) which detonates the clearing charge (P07 / P02-5) on the upside of the mine. The selector switch is a rectangular machined surface in the S&A unit with two holes, a top and a bottom one. An interrupter disc (P03-P04-20) , locking off one of both holes is placed in a rectangular frame called the interrupter retainer (P03-P04-21), placed behind the holes. After the mine has landed, the disc falls down, always locking off the lower of both holes, ensuring it is always the top cover that is blown off (P08).
The millisecond delay detonator (P04-22) is initiated by the M100 micro detonator (P04-17) , which ignites the centre lead (P04-23) and the four main charge output leads (P03/P04-24) in the S&A mechanism. This ignites the ring shaped PBXN-5 charge around the S&A unit (P01-8), which ignites the main charge, throwing away both discs (P01-3), according to the Misznay-Shardin effect.
Penetration of the mine is stated to be 61mm (2,4 inch) of armour steel plate.
The mine weighs 1,91 Kg (4,20 pounds).
An interesting you tube movie showing the BLU-91-B AT mine in use can be found here: https://www.youtube.com/watch?v=OBqdtq-6gcw
Description and functioning of the BLU-92/B anti-personnel mine:
The BLU-92B closely resembles the BLU-91B anti tank mine in outer appearance. It has the same dimensions as the BLU-91-B. The easiest observable difference are the four oval shaped ports (P10-25) -at 90 degrees each- in the top and base plate of the cylindrical part of the mine, which house the eight trip wire assembly’s . A sheet metal top and base plate (P10-26) locks up all inner parts and is connected with the scored (P10-27) steel fragmentation sleeve by means of a rolled seam.
The BLU-92B is an air delivered , free fall, bidirectional , electromechanically armed anti personel mine. It is detonated by means of 12 meters long tripwires or self destruct (T1,T2,T3) . Some mines have an additional anti disturbance switch, which detonates the mine if moved.
The mine is constructed as follows:
The centre of the mine houses the same S&A mechanism (P03,P04) as the BLU-91B . Around it, two mirrored black PVC tripwire assemblies are placed, (P09-, P11-28) each housing four tripwire assembly’s at 90 degrees each. Between the two assemblies a cast in electronics disc is placed (P11-29), housing the self destruct timer mechanism, the additional anti disturbance fuze (with some mines) and the firing circuit electronics. One of both tripwire sensor assembly’s houses the two lithium battery cells (P09/P10-30) delivering 6,4 volts. Below the battery, the MCS (Magnetic Coupling Sensor) assembly (P09/P10-31) is placed. Four detonators (P09-32), -at 90 degrees each- are placed in the explosive charge (P09-35), each connected to the S&A device with a connection pipe (P09-33) filled with explosives. Around the black PVC tripwire assemblies an aluminium ring shaped container (P09-34) is placed housing the 400 grams (14,1 Oz) Composition B4 explosive charge (P09-35).
Around the explosive charge the ring shaped scored steel fragmentation sleeve (P10-27) is placed. The mine is completed with the aero ballistic adapter. After landing, the aero ballistic adapter may break away from the mine, leaving a cylinder only.
The mines receive an electric arming and self destruct pulse signal at the opening of the dispenser. This pulse is induced to the MCS (P09/P10-31) (Magnetic Coupling System), simultaneously initiating the battery primer, opening the self destruct fusible links, mechanically locks out a bore rider safety mechanism, and opens a short circuit on a firing capacitator (condensator). When initiated, the battery (P10-30) primer activates two Lithium battery cells, providing the 6,4 volts.
Subsequent battery power starts electronic timing circuits in the electronics assembly, that controls arming and -one of three; (T1,T2,T3) self destruct times.
When packed in the CBU, the mines are stacked, the bore rider safety plate (P09-36) kept in locked position by the mine below and above.
Upon release from the CBU, the bore rider safety plate is blown off by the air stream, allowing the spring loaded bore rider pin (P03-2) to rise and release one of two restraints (P03-12) in the safety and arming mechanism, enabling the mine to complete its arming cycle after the mine has come to rest on the ground.
Approximately 105 seconds after the initial arming pulse, a micro piston actuator fires (P04-13) , breaking the slider release pin (P04-14) and removing the slider release (P04-15) away from the slider , allowing the spring loaded slider (P04-16) to move into explosive alignment.
Simultaneously, the electronics fires the pressure cartridge which releases the restraints on the tripwire springs. The pressure cartridge is a bidirectional gravity switch that senses which tripwire assembly disc is facing upward. Each tripline sensor is series connected to an electronic firing circuit.
Each tripwire assembly is a pressed aluminium cup (P10-37), housing a strong spring (P10-38). A cup with four hooks (P10-39) is placed in this cup pushing the spring inward tight. A spool (P10-40) housing 12 mtrs of fine green wire is riveted to the cup with the hooks. The lower portion of the spool is connected to the small ejection (P10-41) charge. The ejection charge is meant more to release the trip wire spool from it’s impact safe position than to launch the tripwire, which is done by the spring.
The wire is 12 mtrs long, so when fully used the four wires (at 90 degrees each) form a square of 17x17 mtrs in which one will encounter a tripwire.
When the tripwire is pulled with a force between 4,8 and 14 ounces (136 and 379 grams) , a breakwire in the bottom of the tripwire cup breaks, activating the detonator in the S&A mechanism.
Regards, DJH
Sources:
http://fas.org/man/dod-101/sys/land/fascam.htm
-TM U.S. Landmine APERS, BLU-92/B (Gator).
-TM U.S. Landmine AT/AV, BLU-91/B (Gator).
Attachments
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P01 - BLU-91B AT mine cutaway model detector at base.JPG -
P02 - BLU-91B AT mine cutaway model detector in top.JPG -
P03 - BLU-91B & BLU-92B fuzing system.JPG -
P04 - BLU-91B & BLU-92B fuzing system.jpg -
P05 - BLU-91B AT mine electronics and Detector spool bottom.JPG -
P06 - BLU-91B AT mine electronics and Detector spool top.JPG -
P07 - BLU-91B AT mine expulsion charge.JPG -
P08 - BLU-91B AT mine blowing cover for EFP.JPG -
P09 - BLU-92B AP mine cutaway model with safety flap.JPG -
P10 - BLU-92B AP mine as laid and activated.JPG
