Recoilless Flashcards
551 Rocket Motor Assembly (RMA) components
Body
Propelling charge
Aft closure
Delay charge
Intermediate charge
Ignition charge
551 How is the RMA secured to the projectile body in the 551
Secured to the projectile body by an internal
thread
551 Tail fin assembly 551
Six cold extruded aluminium fins
A plunger (incorporating two throttling orifices)
551 What do the fins achieve on the 551
Reducing the spin rate to approx 450 rpm
551 Arming distance
The arming spring then moves the rotor through 270 degrees to the armed position (5 to 15 metres into the flight)
Muzzle velocity of FFV551
255 m/s
Angle of Impact FFV551
10 deg minimum
Range HEAT 551
150m-700m
Operating limitations General FFV551
Temperature : -40ºC to +71ºC
Firing from within enclosed positions prohibited
Double hearing protection pers within 25m
Wearing of hearing protection within 100m of firing
There should be no range obstructions to 30m from the firing point
Targets to be @ > than 150m
*Ricochet Distance FFV551
350m normal target Hard Target 700m
Operating Limitations Cook Off FFV551
A platform temperature of 115ºC should not be exceeded
A maximum of ten rounds may be fired in close sequence
A maximum of twenty five rounds can be fired at a rate of fire of six rounds per minute
Rate of fire for prolonged firings is to be considerably less than five rounds per minute
*Operating Limits Blast Overpressure FFV551
Blast Overpressure: Number of firings per firer per day (peace time):
Standing seven
Kneeling/Sitting one
Prone zero in peacetime
Proof Requirements FFV 551
Proof Requirements
Functional requirements
Penetration of Armour 400mm (approx) and produce behind armour effects
Must function on both direct impact and graze impact on a target
When fired at the centre of a vertical target, at 300+5m the max distance between the MPI and point of aim must not exceed 0.4m
551 What is the RKT MT propellant type & QTY?
AKB 250m Double Based Strip 270g
Critical Performance Parameters (CPP) FFV551
Positions of Impact Points on the target Vertical and horizontal co ordinates of impact points, measured from the lower left hand corner of the target, are to be recorded
Positive values on the horizontal axis are to the right of the lower left hand corner (recorded in metres)
Muzzle Velocity is to be recorded for all tests
Blast Over Pressure is to be recorded for all tests
Rocket Motor Ignition Distance Rounds are to be observed to determine whether a Ignition Distance of at least 13m is achieved.
Recoil Energy Recoil Energy (Joules) is to be recorded for all tests
Weapon system for 545/545C
84mm M1/2 Medium Direct Fire Weapon System Carl Gustaf
84mm M3 Carl Gustaf – replacement variant
545/545C construction
Flare container
Filled: 0.57kg of Magnesium/Sodium Nitrate
Illuminating Composition
Produces 650,000 candlepower
Average burn time: 30 + 5 seconds
Parachute
Connected to Illumination canister by a swivel
Nylon canopy and shroud lines
Asbestos-fabric Flare Shield
Slows candle descent rate to 5m/s
Three short and one long half-casing surround
parachute assembly
545 Combustion time fuze time setting
The ring has graduations from 200 metres to 2300 metres in 50 metre increments and an ‘S’ graduation to indicate safe
Additionally, the ring has three preset catches at the 600, 1100 and 1700 metre graduations to allow setting of the fuze to these distances in total darkness
The fuze is supplied in the ‘S’ position and the ring may only be turned in an anti-clockwise direction where the distance decreases starting at 2300 metres
545 luminosity
650000 candlepower for
30 seconds
545 Muzzle velocity
260 m/s
545 Arming distance
20-70m
545 HOB
200m (approx) - achieved with eleveations of 20° @ 500-1800 and 25° for 300-400 and 1900-2300m using a luminous flare pendulum sight
Cart 84mm 545 has the following functional
requirements:
Time to Burst. At a charge temperature of +21ºC, the time to burst, and corresponding distances are:
600m (short range) 2.6 sec 0.25 sec
1100m (medium range) 5.5 sec 0.30 sec
1700m (long range) 9.4 sec 0.35 sec
545 Critical Performance Parameters (CPP)
a. Time to Burst. Flight times (seconds) before burst
b. Muzzle Velocity. Muzzle Velocity, vm(ms 1),
c. Blast Overpressure (BOP). Blast overpressure (kPa)
d. Recoil Energy. Recoil Energy (joules) is to be recorded for all tests
e. Candle Burn Time.
f. Luminosity.
545 Test Reqs.
Muzzle Velocity and Functioning. Rounds are to be conditioned at 21º C + 2º C for a minimum of 12 consecutive hours
Point of Aim. Quadrant elevation is to be 20º
FFV545C difference from 545
Includes Electronic Fuze F555, has I for impact mode (200 G’s)
545C wait time for UXO?
545C has 60 minute wait time after ground
impact to allow the capacitor to breed down
545C arming distance
40-85m
How many pre selected ranges does the
545C have?
What do they range from?
seven ranges - 300 - 2100m
HE 441B Warhead fill
The steel body encloses two neoprene rubber inserts that contain a total of 800 steel balls (approximately).
The inserts surround the main HE filling of 345g RDX/TNT.
HE 441B MTSQ Fuze FFV 447
It is an MTSQ impact fuze with graze function. The time and impact functions work independently of each other so that in the event of a time function failure the projectile will still detonate on impact, even when set to the safe position.
A mask safety in the fuze allows the projectile to pass through multiple targets equivalent to 40 mm pine planks from 0 to 20m without functioning.
This allows the round to be used in urban combat where it can be fired through doors or similar entry points and function inside a building.
The fuze requires both setback and spin forces to initiate the arming sequence.
The major components of the fuze are the body, nose cap, clockwork mechanism (THIEL) and safety and impact (S and I) unit.
The cap is marked with a setting scale with ranges from 40 to 1250 metres in 10m increments and a safe position indicated with an ‘S’.
20mm sub cal MV and range
Proj exits the barrel at 220m/S and functions
out to a range of 300m (max range 1750m)
20mm sub cal firing limitations
Blast Over Pressure (BOP) limits:
(1) Standing position 100 firings per day
(2) Kneeling/Sitting position one firing per day
(3) Prone position Prohibited
Graze angle of the HE 441B?
5 degrees
HE 441B Ricochet
Ricochet distance (m)
350 normal
700 (hard target)
84mm High Explosive Dual Purpose
(HEDP) 502 main components w/ fill
HEDP 502 Projectile Assembly Shaped charge
590g Octol
Cartridge Case A ssembly 340g NK 1287
propellant
84mm HEDP 502 Cart Case Assembly
consists of:
Base Plate( Laminated paper impregnated
with phenolic resin)
Igniting composition ( Z47B)
Propellant charge (AKB204) NK1287
Cart case (Light metal
Alloy)
Two modes of the HEDP 502?
Delay 0.1 seconds - no SC jet formed (liner crushed) APers frag
Impact - piezo electric, SC jet formed
HEDP 502 ranges
Vehicles 300m
Field Fortifications 500m
Maximum 1650m
HEDP 502 arming distance
Arming Distance (m) 12-40 m
HEDP 502 MV
225m/s
HEDP 502 armour penetration and angle of impact?
Armour Penetration >100mm
Angle of Impact
Minimum 15 degrees normal
Maximum 75 degrees normal
SMK 469B effect
instantaneous screen of white smoke
covering an area of 5 to 7.5m (approx)
SMOKE 469B fuze
Fuze 957B
It is a direct action and graze fuze provided with a safety device. The fuze functions both as the result of direct impact with the nose of the fuze and at low angles of impact (graze). The impact mechanism of the fuze permits the fuze to function down to low angles of impact of approximately 5°. The detonator safety device (Figure 4) is identical to the 447 Fuze in the Cart 84mm HE 441B.
SMOKE 469B fill and burster
Smoke Composition (800gm titanium tetrachloride absorbed by pulverous synthetic calcium silicate)
Burster Charge (12gm RDX/TNT)
SMOKE 469B cartridge composition:
Igniter composition(Z47B)
Base Plate ( Laminated paper impregnated with phenolic resin)
Percussion Primer (Z2A)
Propellent Charge( AKB204) NK1287
469B arming distance
The arming delay permits the projectile to be fired through a mask of 25mm pine plank within a distance of 20 metres, without functioning. Fuze 957B achieves full arming within
the range of 20 - 70 metres.
SMOKE 469B MV
Muzzle Velocity (m/s) 240m/s
SMOKE 469B time of flight
Time of Flight (sec) 1.8s( 400m)
SMOKE 469B range
Range (m) 1300m (effective)
ASM 509 modes
Instananeous (I) - electric initiation (piezoelectric) and Delay (D) pyrotechnic initiation (magnetic intertia pellet - piezoelectric shortcircuited)
ASM 509 delay
30 ms
ASM 509 failsafe
escapement released before driving plunger pressed down, rotor lock turns 260° into failsafe position
ASM 509 targets
structures, also light armoured vehicles. Enhanced blast explosives with splinter effects.
SMOKE 469B purpose
Blind DF weapons e.g. supporting tanks, SP guns, MG’s
ILLUME 545 fill
Illuminate Composition MG/NaNO3 570g
ILLUME 545 firing limits
standing 4 per day
kneeling/sitting one per day
prone prohibited
HE 441B targets
unprotected troops, entrenched troops, field fortifications, soft skinned vehicles or other similar
Blow out disc construction
Laminated paper impregnated with phenolic resin
HE 441B range
150m-1000m (max eff.)
HEDP 502 Targets
Light armoured vehicles (Impact) / Personnel in light cover, field forts, buildings and similar in urban areas (Delay)
TP 552 ranges
150m engagement
700m effective
2900m maximum (at 35° qdnt elev. QE)
TP 552 description
wieght, CoG and ballistics and rocket motor assembly matched to HEAT 551 projectile
