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08
January 2001
RO Defence 120mm tank gun
ammunition
Armament
120 mm L11 tank gun; 120 mm L30A1 (CHARM) tank gun.
Development
British 120 mm tank guns are rifled as opposed to the smoothbores of the
Rheinmetall DeTec and similar 120 mm tank guns. The first service version of the
current 120 mm guns was the L11. The L11 was fitted to the Chieftain series and
Challenger 1 MBTs (the earlier Conqueror used an entirely different gun and
ammunition family) and was developed to the L11A5 stage. Development work was
also carried out on a series of next-generation `Modern Technology' tank guns,
which resulted in the 120 mm L30A1 (CHARM - CHallenger ARMament) gun fitted to
the Challenger 2 MBT and, at one time, destined to be retrofitted to the
Challenger 1.
The L30A1 gun can continue to fire the existing range of Royal Ordnance (now BAE
Systems, RO Defence) 120 mm ammunition (apart from the APDS L15) and new
high-performance APFSDS projectiles. However, the L30 gun uses a new propellant
charge system, the L14, to fire APFSDS. The L14 propellant system, which is
based on rigid Combustible Case Charges (CCC), was modified to allow it to be
used operationally with L11 guns during Operation Granby/Desert Storm. The code
word for this project was Jericho.
Description
All RO Defence 120 mm tank gun ammunition is manually separate loaded, although
the bundled stick propellant charges may be loaded in either calico bags or as
rigid thin-walled CCC; at one time bagged charges were used for all types of
projectile. All charges are ignited electrically via vent tubes fed from a vent
tube loader. The vent tubes may be the L3 for the L11 gun or L4 for the L30 gun.
The main types of projectile involved are as follows:
APFSDS L23 This is the main
projectile used for the attack of armour and involves a monobloc tungsten nickel
copper long rod penetrator carried in a light alloy sabot. The penetrator rod
uses six aluminium fins. The projectile assembly is fired using an L8 CCC
containing 6.65 kg of AX/S64-20 triple-base propellant in stick form. It can
also be fired using a modified L14 CCC. Muzzle velocity is 1,534 m/s and the
maximum effective range is given as 3,500 m.
APFSDS L26 Originally the
XL26E1, this projectile is intended for use in the 55 calibre L30 gun currently
used on the Challenger 2 MBT and, at one time, intended to be retrofitted to the
Challenger 1. The original CHARM 1 system version of this projectile used a
Depleted Uranium (DU) penetrator rod. For the L30 gun the L26 is fired using the
L14A1 or L14A2 CCC which contains RDX-based propellant in stick form. This
projectile can also be fired from L11 guns using the L8 or L12 charges. The
total weight of this projectile is 8.5 kg and it is 525 mm long overall.
APFSDS L27 This is known as
the CHARM 3 APFSDS, with a greater Depleted Uranium (DU) penetrator
length-to-diameter ratio than earlier models and is thus `significantly more
effective'. Integration development of the CHARM 3 round began during the early
1990s but was delayed from 1997 onwards by a lack of ranges suitable for firing
trials within the UK. Even so the APFSDS L27A1 became available for service with
British Army Challenger 2 MBT regiments during 1999, ahead of the planned
schedule. The L27A1 is fired using the L16A1 CCC.
A competition to provide a CHARM 3 Training Round (C3TR) for the L27 was won by
RO Defence at the end of 1999. The 120 mm C3TR consists of a charge and a
saboted projectile assembly and, following development, will be manufactured at
Birtley and Glascoed.
APDS L15 The APDS round was
the original anti-armour element of the 120 mm L11 series tank gun ammunition
family. While it has been largely replaced as the primary anti-armour round by
APFSDS rounds the APDS L15 remains a potent armour-piercing munition with a high
hit probability at combat ranges; it has been estimated that the APDS L15 can
penetrate 355 mm of armour at 1,000 m. The subprojectile is stated to be capable
of penetrating the armour of most current MBTs at battle ranges. The APDS L15
uses a dense tungsten alloy penetrator subprojectile carried in a light alloy
sabot. The projectile assembly is fired using the L4 CCC which contains 8.4 kg
of NQ/S53-12 propellant. Muzzle velocity is 1,370 m/s.
120 mm APDS L15 is not fired from the L30 gun.
DS/T Prac L20A1 This is a
relatively low-cost training projectile with the subprojectile penetrator made
from steel with a light alloy nose. The DS/T Prac L20A1 subprojectile matches
the trajectory of the APDS L15 out to 1,100 m, after which it requires a much
smaller safety trace than the operational L15 subprojectile (the L20A1 also
extends barrel life). The L20A1 can also be used as a training equivalent to the
APFSDS L23 out to a range of 2,000 m. The DS/T Prac L20A1 is fired using the L5
CCC which contains 5.16 kg of NQ/S27-09 propellant. Muzzle velocity is 1,451
m/s.
British Army consumption of the DS/T L20A1 was forecast to run at about 60,000
units per year until 1998.
HESH L31 The HESH L31 is
employed as a general purpose round with a good anti-armour performance as it is
capable of defeating a NATO heavy single target at all ranges up to a maximum of
8,500 m; it can also be used in the indirect fire role. The projectile consists
of a thin-walled projectile with a rounded ogive filled with 4.2 kg of RDX/Wax
explosive detonated by a base percussion fuze. As with other projectiles of its
nature, when the HESH L31 projectile strikes a target the thin walls collapse to
allow the explosive to be spread over the surface of the target before the base
fuze functions. The resultant detonation creates shock waves which force off a
large high-velocity scab of material from the inner surface of the target armour.
The latter capability makes the HESH L31 projectile effective against
fortifications and structures as well as armoured targets. The HESH L31 is fired
using the L3 bag charge containing 3.04 kg of NQ/S27-09 triple-base propellant.
Muzzle velocity is 670 m/s.
SH/Prac L32A6 This training
projectile is used to simulate the operational HESH L31 which it matches
ballistically. The SH/Prac L32A6 is available in a completely inert form, filled
with an inert HE substitute (a composition of calcium sulphate and castor oil),
or an inert HE substitute plus a live fuze and a flash pellet for spotting
purposes. Four small tracers are housed in the projectile base. As with the HESH
L31, the SH/Prac L32A6 is fired using the L3 bag charge containing 3.04 kg of
NQ/S27-09 propellant. Muzzle velocity is 670 m/s.
British Army consumption of the SH/Prac L32A6 was forecast to run at about
20,000 units per year until 1998.
WP Smoke L34 In visual
appearance and ballistic performance, the WP Smoke L34 matches the HESH L31. It
is a bursting type of smoke projectile with which an internal burster charge is
used to break open the projectile's steel walls to release the White Phosphorus
(WP) contents weighing 4.2 kg. The WP then rapidly creates a visually opaque
smoke screen which lasts for at least 30 seconds, depending on the ambient
weather conditions. The WP Smoke L34 is fired using the L3 bag charge containing
3.04 kg of NQ/S27-09 propellant. Muzzle velocity is 670 m/s. If required, the SH/Prac
L32 can be used as a training projectile for the WP Smoke L34.
A Canister projectile was
developed for use with the L11 gun but it was not placed in production. It was
fired using the L3 bag charge and discharged pellets lethal against unprotected
personnel up to a range of 200 m from the gun muzzle.
Drill ammunition, consisting
of inert projectiles and charges, is available.
Specifications
| Type |
APFSDS |
APDS |
HESH |
| Designation |
L23 |
L15 |
L31 |
| Weights: |
|
|
|
| Projectile |
8 kg |
10.36 kg |
17.1 kg |
| Propellant |
6.65 kg |
8.4 kg |
3.04 kg |
| Projectile
length |
512 mm |
|
511 mm |
| Type of
propellant |
AX/S64-20 |
NQ/S53-12 |
NQ/S27-09 |
| Muzzle velocity |
1,534 m/s |
1,370 m/s |
670 m/s |
| Type |
WP Smoke |
DS/T Prac |
SH/Prac |
| Designation |
L34 |
L20 |
L32 |
| Weights: |
|
|
|
| Projectile |
17.3 kg |
5.8 kg |
17.1 kg |
| Propellant |
3.04 kg |
5.16 kg |
3.04 kg |
| Projectile
length |
511 mm |
300 mm |
508 mm |
| Type of
propellant |
NQ/S27-09 |
NQ/S27-09 |
NQ/S27-09 |
| Muzzle velocity |
670 m/s |
1,451 m/s |
670 m/s |
Authorised fuzes
APFSDS and APDS - none involved
HESH and WP Smoke - BD, type not specified
Equivalent rounds
IRAN
Manufacturer
Defence Industries Organisation, Ammunition Division
Type: 120 mm HESH
Description: Understood to be based on HESH L31 but projectile weight given as
16.65 kg containing 3.55 kg of an unspecified explosive. Propellant weight is
2.73 kg and muzzle velocity 670 m/s. Maximum range is 2,530 m. Base fuze given
as BZ 120
RO
Defence 120 mm tank gun projectiles, from left: APFSDS-T L23A1; DS/T
Prac L20A1; HESH L31A7; SH/Prac L32 and WP Smoke L32 (T J Gander)
RO
Defence 120 mm APFSDS-T L26 CHARM 1 projectile
Model
of 120 mm APFSDS-T CHARM 3 projectile
Cross-section
drawing of projectile assembly for 120 mm APFSDS-T L23 produced by RO
Defence (2000)
Cross-section
drawing of Smoke WP L23 projectile produced by RO Defence (2000)
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