RP-3: Difference between revisions
→References: separate notes from refs |
→Rocket engines: format as separate note |
||
Line 201: | Line 201: | ||
;Aircraft rocket motor, 3 in., No. 1, Mk. 4/TH |
;Aircraft rocket motor, 3 in., No. 1, Mk. 4/TH |
||
:The Mk. 4 engines extended the ignition cables to allow for double hanging, were one RP-3 was mounted below another RP-3. During storage the extra length of the ignition cables was held in place by loose metal clips in the [[nozzle]].<ref name="AP2802"/> |
:The Mk. 4 engines extended the ignition cables to allow for double hanging, were one RP-3 was mounted below another RP-3. During storage the extra length of the ignition cables was held in place by loose metal clips in the [[nozzle]].<ref name="AP2802"/> |
||
===Comparison=== |
|||
{| class="wikitable" |
{| class="wikitable" |
||
|- |
|- |
||
|+ |
|+Comparison of warheads{{refn|Unless specified, data is from the [[Swedish Air Force]] 1950 manual "Bestämmelser för rakettjänst".<ref name="rakettjänst">{{Cite book|title=Bestämmelser för rakettjänst |trans-title=Provisions for rocket-use|publisher=Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration)|year=1950|location=Stockholm, Sweden|page=2|language=sv}}</ref> This manual uses original data collected in [[Metric system|metric]] by the [[Royal Swedish Air Force Materiel Administration]].<ref name="Raketbeväpning"/> Compare with [[Imperial units]] data:<ref name=Boyd/><ref name="AP2802"/> |group=note|name=Rakettjänst}} |
||
|- |
|- |
||
! style="width: 20%;" |Warhead |
! style="width: 20%;" |Warhead |
||
Line 212: | Line 212: | ||
! style="width: 20%;" |Shell, P., Concrete, 60 lb |
! style="width: 20%;" |Shell, P., Concrete, 60 lb |
||
|- |
|- |
||
! Warhead diameter |
!style="text-align: left;"| Warhead diameter |
||
| colspan="2" style="text-align: center;" |{{convert|88|mm|abbr=on}} |
| colspan="2" style="text-align: center;" |{{convert|88|mm|abbr=on}} |
||
| colspan="2" style="text-align: center;" |{{convert|152|mm|abbr=on}} |
| colspan="2" style="text-align: center;" |{{convert|152|mm|abbr=on}} |
||
|- |
|- |
||
! Engine diameter |
!style="text-align: left;"| Engine diameter |
||
| colspan="4" style="text-align: center;" |{{convert|82.7|mm|abbr=on}} |
| colspan="4" style="text-align: center;" |{{convert|82.7|mm|abbr=on}} |
||
|- |
|- |
||
! Width with fins |
!style="text-align: left;"| Width with fins |
||
| colspan="4" style="text-align: center;" |{{convert|336|mm|abbr=on}} |
| colspan="4" style="text-align: center;" |{{convert|336|mm|abbr=on}} |
||
|- |
|- |
||
! Warhead length<br>(including spigot) |
!style="text-align: left;"| Warhead length<br>(including spigot) |
||
|{{convert|314|mm|abbr=on}} |
|{{convert|314|mm|abbr=on}} |
||
|{{convert|378|mm|abbr=on}} |
|{{convert|378|mm|abbr=on}} |
||
Line 228: | Line 228: | ||
|{{convert|608|mm|abbr=on}} |
|{{convert|608|mm|abbr=on}} |
||
|- |
|- |
||
! Engine length |
!style="text-align: left;"| Engine length |
||
| colspan="4" style="text-align: center;" |{{convert|1400|mm|abbr=on}} |
| colspan="4" style="text-align: center;" |{{convert|1400|mm|ftin|abbr=on}} |
||
|- |
|- |
||
! Overall length |
!style="text-align: left;"| Overall length |
||
|{{convert|1639|mm|abbr=on}} |
|{{convert|1639|mm|ftin|abbr=on}} |
||
|{{convert|1703|mm|abbr=on}} |
|{{convert|1703|mm|ftin|abbr=on}} |
||
|{{convert|1880|mm|abbr=on}} |
|{{convert|1880|mm|ftin|abbr=on}} |
||
|{{convert|1933|mm|abbr=on}} |
|{{convert|1933|mm|ftin|abbr=on}} |
||
|- |
|- |
||
! Weight of complete rocket<br>with {{convert|17.2|kg|abbr=on}} engine |
!style="text-align: left;"| Weight of complete rocket<br>with {{convert|17.2|kg|abbr=on}} engine |
||
| colspan="2" style="text-align: center;" |{{convert|28.5|kg|abbr=on}} |
| colspan="2" style="text-align: center;" |{{convert|28.5|kg|abbr=on}} |
||
|{{convert|44.6|kg|abbr=on}} |
|{{convert|44.6|kg|abbr=on}} |
||
|{{convert|44.4|kg|abbr=on}} |
|{{convert|44.4|kg|abbr=on}} |
||
|- |
|- |
||
! Warhead weight |
!style="text-align: left;"| Warhead weight |
||
| colspan="2" style="text-align: center;" |{{convert|11.3|kg|abbr=on}} |
| colspan="2" style="text-align: center;" |{{convert|11.3|kg|abbr=on}} |
||
|{{convert|27.4|kg|abbr=on}} |
|{{convert|27.4|kg|abbr=on}} |
||
|{{convert|27.2|kg|abbr=on}} |
|{{convert|27.2|kg|abbr=on}} |
||
|- |
|- |
||
! Explosive charge |
!style="text-align: left;"| Explosive charge |
||
| colspan="2" style="text-align: center;" |none |
| colspan="2" style="text-align: center;" |none |
||
|{{convert|6|kg|abbr=on}} [[TNT]] or Amatol 60/40<ref name="OP1665"/> |
|{{convert|6|kg|abbr=on}} [[TNT]] or Amatol 60/40<ref name="OP1665"/> |
||
|none |
|none |
||
|- |
|- |
||
! Propellant charge |
!style="text-align: left;"| Propellant charge |
||
| colspan="4" style="text-align: center;" |{{convert|5.2|kg|abbr=on}} [[cordite]] |
| colspan="4" style="text-align: center;" |{{convert|5.2|kg|abbr=on}} [[cordite]] |
||
|- |
|- |
||
! |
!colspan="5" |Performance |
||
|- |
|- |
||
! Propellant burn time<br>at {{convert|15|C|abbr=on}} |
!style="text-align: left;"| Propellant burn time<br>at {{convert|15|C|abbr=on}} |
||
| colspan="4" style="text-align: center;" |1.6 s |
| colspan="4" style="text-align: center;" |1.6 s |
||
|- |
|- |
||
! Thrust at {{convert|15|C|abbr=on}} |
!style="text-align: left;"| Thrust at {{convert|15|C|abbr=on}} |
||
| colspan="4" style="text-align: center;" |{{convert|800|kgf|lbf|abbr=on}} |
| colspan="4" style="text-align: center;" |{{convert|800|kgf|lbf|abbr=on}} |
||
|- |
|- |
||
! Maximum velocity |
!style="text-align: left;"| Maximum velocity |
||
| colspan="2" style="text-align: center;" |{{convert|380|m/s|abbr=on}} |
| colspan="2" style="text-align: center;" |{{convert|380|m/s|abbr=on}} |
||
| colspan="2" style="text-align: center;" |{{convert|230|m/s|abbr=on}} |
| colspan="2" style="text-align: center;" |{{convert|230|m/s|abbr=on}} |
||
|- |
|- |
||
! Armour penetration |
!style="text-align: left;"| Armour penetration |
||
| colspan="2" |{{convert|88|mm|abbr=on}} at {{convert|700|yd|abbr=on}}< |
| colspan="2" style="text-align: center;" |{{convert|88|mm|abbr=on}} at {{convert|700|yd|abbr=on}}<ref group=note>A flight time of 1.29 seconds from aircraft travelling at {{convert|350|ft/s|mph|abbr=on}}{{sfn|Boyd|2009}}</ref><ref name=Boyd>Boyd, 2009</ref> |
||
| style="text-align: center;" |not available |
| style="text-align: center;" |not available |
||
| style="text-align: center;" |not available |
| style="text-align: center;" |not available |
Revision as of 11:25, 11 August 2021
RP-3 | |
---|---|
![]() Loading of RP-3 rockets fitted with 60 lb semi-armor-piercing high-explosive warheads onto a Hawker Typhoon | |
Type | Unguided air-to-surface rocket |
Place of origin | United Kingdom |
Service history | |
In service | 1943–1968 (UK) |
Used by | Royal Air Force, Royal Navy, Royal Australian Air Force and others |
Wars | World War II, Indonesian National Revolution, Malayan Emergency, Suez Crisis, Korean War, Aden Emergency |
Production history | |
Variants | see variants |
Specifications | |
Mass | 35 lb (16 kg)17.9 kg (39 lb) Mk 1 engine 17.2 kg (38 lb) Mk 2, 3, 4 engine |
Length | 55 in (1.4 m) rocket 20–22 inches (500–560 mm) warhead |
Diameter | 3.25 in (83 mm) rocket body |
Warhead | TNT/RDX/Amatol |
Warhead weight | 1.3–5.5 kg (2.9–12.1 lb) |
Engine | solid fuel rocket 800 kgf (1,800 lbf) |
Propellant | cordite |
Operational range | 1,600 m (1,700 yd) |
Maximum speed | With 25 lb warhead: 380 m/s (1,200 ft/s) With 60 lb warhead: 230 m/s (750 ft/s) |
Guidance system | unguided |
Launch platform | Several aircraft Landing Craft Tank (Rocket) |
The RP-3 (from Rocket Projectile 3 inch) was a British air to ground rocket projectile used during and after the Second World War. The "3 inch" designation referred to the nominal diameter of the rocket motor tube. The use of a 60-pound (27 kg) warhead gave rise to the alternative name of the "60-pound rocket". Though primarily an air-to-ground weapon, it saw limited use in other roles. They were generally used by British fighter-bomber aircraft against targets such as tanks, trains, motor transport and buildings, as well as by Coastal Command and Royal Navy aircraft against U-boats and ships.
History
The first use of rockets fired from aircraft was during World War I. The "unrotated projectiles" (UPs) were Le Prieur rockets which were mounted on the interplane struts of Nieuport fighters. These were used to attack observation balloons and were reasonably successful. Sopwith Baby and Pup and Home Defence B.E.2 fighters also carried rockets.[1][page needed]
With the war ended the Royal Air Force, intent on retrenching, forgot about firing rockets from aircraft. The British Army, however, did see a use for rockets against low-flying aircraft; from late 1940 parts of Britain were defended by increasing numbers of "Z-Batteries" 2-inch (51 mm) rockets supplementing the conventional anti-aircraft guns.[1][2][page needed]
When German forces under the command of Rommel intervened in the Western Desert from early 1941, it became clear that the Desert Air Force lacked weapons capable of damaging or destroying the large numbers of armoured fighting vehicles, particularly the heavier Panzer III and Panzer IV tanks possessed by the Germans. Consequently, in April 1941 Henry Tizard, the Chief Scientist, called together a panel to study "Methods of Attacking Armoured Vehicles."[1]
The types of weapons investigated included the 40 mm Vickers S gun and related weapons manufactured by the Coventry Ordnance Works, as well as the Bofors 40 mm and the US 37 mm T9 cannon fitted to the Bell P-39 Airacobra: however, it was already recognised that these weapons were only capable of dealing with light tanks and motor transport, and using larger weapons on fighter-bombers was ruled out because of weight and difficulties handling recoil. The chairman of the panel, Mr. Ivor Bowen[3] (Assistant Director of Armament Research) turned to the idea of using rocket projectiles as a means of delivering a large warhead capable of destroying or disabling heavy tanks. Information was sought from the Soviets, who had just started using unguided RS-82 rockets against German ground forces in the opening phases of Operation Barbarossa.[1][note 1]
By September 1941 it was decided that two models of UP would be developed:
- A 23 lb plastic explosive on a standard 2-inch UP.
- A 20 lb solid armour-piercing head on a 3-inch UP.
When it was realised that the 2-inch version would be less effective than the Vickers S cannon, it was decided to concentrate on development of the 3-inch version, which could be developed from the 2-inch rocket used in the Z-Batteries.[1]
Design
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/6e/3_in_RP_Attaching_60_pdr_Warheads.jpg/220px-3_in_RP_Attaching_60_pdr_Warheads.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/04/31_Squadron_RAAF_Beaufighter_loading_practice_RP-3_Coomalie_Creek_NT_Nov_1944_AWM_NWA0672_%28cropped%29.jpg/220px-31_Squadron_RAAF_Beaufighter_loading_practice_RP-3_Coomalie_Creek_NT_Nov_1944_AWM_NWA0672_%28cropped%29.jpg)
The rocket body was a steel tube 82.7 mm (3.26 in) in diameter filled with 5.2 kg (11.5 lb) of cordite propellant, fired electrically.[note 2] The warhead was screwed into the forward end, and was initially a solid 11.3 kg (24.9 lb), 88 mm (3.46 in) diameter armour-piercing warhead which was quickly supplemented by a 152 mm (5.98 in), 27.4 kg (60.4 lb) high explosive head.[note 2] For practice there were also a 25-pound (11 kg) mild steel semi-armour-pericing warhead, a 25-pound (11 kg) concrete practice head[4] and a 27.2 kg (60.0 lb) concrete practice head.[note 2] Once the rocket had been mounted on the rails, an electrical lead (or "pigtail") connected the rocket to the firing controls.
Four large tailfins induced enough spin to stabilize the rocket, but as it was unguided, aiming was a matter of judgment and experience. Approach to the target needed to be precise, with no sideslip or yaw, which could throw the RP off line. Aircraft speed had to be precise at the moment of launch, and the angle of attack required precision. Trajectory drop was also a problem, especially at longer ranges.[note 3][5]
On the plus side the rocket was less complicated and more reliable than a gun firing a shell, and there was no recoil on firing. It was found to be a demoralising form of attack against ground troops, and the 60-pound warhead could be devastating. The rocket installations were light enough to be carried by single-seat fighters, giving them the punch of a cruiser.[note 4] Against slow-moving large targets like shipping and U-boats, the rocket was a formidable weapon.
The weight and drag of the all-steel rails initially fitted to British aircraft blunted performance. Some aircraft such as the Fairey Swordfish biplane used against submarines had steel "anti-blast" panels fitted under the rails to protect the wing, which further increased weight and drag. Aluminium Mark III rails, introduced from late 1944, reduced the effect. American experience with their own rockets (the USAAF's 3.5-Inch Forward Firing Aircraft Rocket (FFAR) and the US Navy's 5-inch FFAR and HVAR[6]) showed that the long rails and anti-blast panels were unnecessary; zero-length launchers were introduced in May 1945. British aircraft started being fitted with "zero-point" mounting pylons in the post-war years.
The 3-inch rocket motors (less warhead) were used in the 'bunker buster' "Disney bomb" (official name: 4500 lb Concrete Piercing/Rocket Assisted bomb), 19 of them propelling the 4,500-pound (2.0 t) bomb to 990 mph (440 m/s) at impact with the target.[7]
Service history
Air-to-ground use
![](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Hawker_Typhoon_showing_salvo_of_rocket_projectiles.jpg/220px-Hawker_Typhoon_showing_salvo_of_rocket_projectiles.jpg)
Before the new weapon was released for service extensive tests were carried out by the Instrument, Armament and Defence Flight (IADF) at the Royal Aircraft Establishment, Farnborough. Hawker Hurricanes were fitted with rockets and rails and flown during June and July 1942. Further tests were undertaken from 28 September to 30 November to develop rocket firing tactics. Other aircraft used were a Lockheed Hudson, a Fairey Swordfish biplane torpedo bomber, a Douglas Boston medium bomber and a Sea Hurricane.[5] At the same time the Aeroplane and Armament Experimental Establishment (A&AEE) had to develop tactics for all the individual aircraft types which were to be armed with the RPs. Aiming was through a standard GM.II reflector gunsight. A later modification enabled the reflector to be tilted with the aid of a graduated scale, depressing the line of sight, the GM.IIL.[8] For rockets only the Mk IIIA was the most successful – it was used on the Lockheed Ventura and Hudson.
The first operational use of the RP was in the Western Desert as a "tank-busting" weapon on Hawker Hurricane Mk. IIEs and IVs. The 25-pound armour-piercing heads were found to be ineffective against the Tiger I heavy tanks coming into German service. With the example of the success of Royal Artillery gunners using high-explosive shells from their 25 pdr gun-howitzer, it was decided to design a new 60-pound semi-armour-piercing (SAP) head. These were capable of knocking turrets off tanks.[citation needed]
A typical RP-3 installation was four projectiles on launching rails under each wing. A selector switch was fitted to allow the pilot to fire them singly (later omitted), in pairs, or as a full salvo. Towards the end of the war some RAF Second Tactical Air Force Hawker Typhoons had their installation adapted to carry an additional four rockets doubled up under the eight already fitted.[9]
Possibly the best known[citation needed] action involving RP-3s was that of the Falaise pocket of mid-August 1944. During the battle German forces, retreating to avoid being trapped in a pincer movement by Allied ground forces, came under air attack. Amongst the waves of light, medium and fighter bombers attacking the German columns the Typhoons of 2 TAF attacked with their rockets, claiming hundreds of tanks and "mechanised enemy transport".[note 5] After the battle Army and 2nd TAF Operational Research Sections studying the battleground came to the conclusion that far fewer vehicles (17 in total) had been destroyed by rocket strike alone. What was clear was that in the heat of battle it was far harder for pilots to launch the weapons while meeting the conditions needed for accuracy. Smoke, dust and debris in the target areas made accurate assessment of the damage caused almost impossible.[9]
But it was also clear rocket attacks devastated the morale of enemy troops – many vehicles were found abandoned intact, or with only superficial damage. Interrogation of captured prisoners showed that even the prospect of rocket attack was extremely unnerving for them.[9]
Anti-submarine
![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/06/Swordfish_landing_on_HMS_Tracker_WWII_IWM_A_19718.jpg/220px-Swordfish_landing_on_HMS_Tracker_WWII_IWM_A_19718.jpg)
Soon after some encouraging results from the initial deployment, trials of the weapon were conducted against targets representing U-boats. It was discovered that if the rockets were fired at a shallow angle, near misses resulted in the rockets curving upwards in seawater and piercing the targets below the waterline. Soon Coastal Command and the Royal Navy's Fleet Air Arm aircraft were using the rockets extensively.
The first U-boat destroyed with the assistance of a rocket attack was U-752 (commanded by Kapitän-Leutnant Schroeter), on 23 May 1943, by a Swordfish of 819 Naval Air Squadron (819 NAS). The rockets used on this occasion had solid, cast-iron heads and were known as "rocket spears".[10] One of these punched right through the submarine's pressure hull and rendered it incapable of diving; the U–boat was scuttled by its crew. On 28 May 1943, an RAF Hudson of 608 Squadron destroyed a U-boat in the Mediterranean, the first destroyed solely by rocket.[5] These rockets were, among other factors, credited with making it too dangerous for the Germans to continue operating their Flak U-Boats, which were fitted with heavy anti-aircraft weaponry and acted as escorts for U-boats crossing the Bay of Biscay.
From then until the end of the Second World War in Europe, Coastal Command and the Fleet Air Arm used the rockets as one of their primary weapons (alongside torpedoes, which, to a certain extent they replaced) against shipping and surfaced U-boats.
Ground-to-ground use
As part of the initial bombardment of the landing areas for the Normandy landings June 1944, Landing Craft Tank (Rocket) armed with RP-3 rockets were used. The LCT(R) fired the rockets in large salvoes.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/36/The_British_Army_in_North-west_Europe_1944-45_BU4676.jpg/220px-The_British_Army_in_North-west_Europe_1944-45_BU4676.jpg)
In 1945, some British M4 Sherman tanks were fitted with two or four rails – one or two either side of the turret – to carry 60-pound headed rockets. These were used at the Rhine Crossing by tanks of the 1st Coldstream Guards. The tanks were called "Sherman Tulips". The tanks fitted included both conventional Shermans and the more heavily armed Sherman Fireflies.[11]
The modifications were first tried out by two officers of the 1st Armoured Battalion, Coldstream Guards, 5th Guards Armoured Brigade, who obtained rockets and launching rails from an RAF base and carried out the first test firings on 17 March 1945. They were inspired after hearing the idea had been earlier tried, but abandoned, by a Canadian reconnaissance unit, the 18th Armoured Car Regiment (12th Manitoba Dragoons), who had fitted RP-3 rails to a Staghound Armoured Car in November 1944.[11] There are photos of four such rockets on a Cromwell cruiser tank, however little is known about it for certain.
Within a week all the tanks of Number 2 Squadron had been fitted with launch rails, some tanks had two launching rails, others had four. The rails were at fixed elevations and the rockets had fixed ranges either 400 or 800 yards (370 or 730 m).[11]
The rockets were highly inaccurate when fired from a tank as they were being fired from a stationary point and had little slipstream over the fins. Despite this, the RP-3 was valued by tank crews for the destructive effect of its 60-pound warhead.[12][page needed] In combat, they were also used for short-range, saturation bombardment of an area and were effective as an immediate counter to German ambushes.[11]
Swedish service
The RP-3 rocket saw use with the Swedish Air Force from 1946[13] to 1957.[14]
Sweden had been experimenting with caseless ammunition as a substitute for air to ground rockets during WWII as it was thought that caseless ammunition would be cheaper to produce. This however proved false and by the end of the war the Swedish air force had moved to rocket development instead.[13] The Swedish weapons company Bofors had been developing rockets on their own initiative since 1943 but, due to lack of funding, did not have a design by the time the Swedish air force gained interest.[13] As it would take years to develop indigenous rockets for the Swedish air force it was decided to buy rockets from abroad to gain operational experience which could be used in indigenous development. The choice of rocket quickly became the RP-3 and Sweden ordered a batch in 1946 for trials.[13]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Saab_b17_RP-3_rocket.jpg/220px-Saab_b17_RP-3_rocket.jpg)
It was quickly decided to perform initial trials on the Saab B 17A dive bomber as it was readily available.[13] In May 1946 a B 17A was fitted with rocket mounts for ground trials. Soon a Saab B 18B was also modified for RP-3 ground trials. The first firing trials took place at F 14 Ringenäs (belonging to Halland wing) during July 1946. Twenty six '60 lb Practice' rockets were fired from the B 18B and three from the B 17A. Six '25 lb AP' and '60 lb SAP' rockets each were also fired from the B 17A.[13] The trials were successful and the RP-3 entered service with the Swedish Air Force.[13]
In Swedish service the RP-3 and its components were given Swedish Air Force designations.[13] The RP-3 system as a whole was designated "8 cm raket m/46", (English: 8 cm rocket model 46).[13] The RP-3 rocket engines that Sweden acquired were most likely the Mk.4/TH type[4] based on available photos and descriptions.[13] These were designated 8 cm raketmotor m/46 (8 cm rakmo m/46), English: 8 cm rocket engine model 46.[13] The square fins were designated 8 cm fena m/46, English: 8 cm fin model 46.[13]
The Swedish Air Force adopted four warheads for the RP-3 rocket: the 25lb AP No.1, 25lb AP No.2, 60lb SAP No.2 and 60 lb Practice.[13]
- 25 lb AP No.1 was designated 8 cm Pansarspets m/46A, English: 8 cm armour tip m/46A, in 1951 redesignated to 8 cm 'pansarhuvud m/46A (8 cm phu m/46A), English: 8 cm armor head m/46A.[13]
- 25 lb AP No.2 was designated 8 cm Pansarspets m/46B, English: 8 cm Armor tip m/46B, in 1951 redesignated to 8 cm pansarhuvud m/46B (8 cm phu m/46B), English: 8 cm armor head m/46B.[13]
- 60 lb SAP No.2 was designated 8 cm Sprängspets m/46, English: 8 cm Explosive tip m/46, in 1951 redesignated to 8 cm spränghuvud m/46 (8 cm shu m/46), English: 8 cm explosive head m/46.[13]
- 60 lb Practice was designated 8 cm Övningsspets m/46, English: 8 cm Practice tip m/46, in 1951 redesignated to 8 cm övningshuvud m/46 (8 cm övnhu m/46), English: 8 cm practice head m/46.[13]
In combination with the engine and square fins these warheads would produce the following rockets:
- 8 cm Pansarraket m/46A, English: 8 cm Armor rocket m/46A, in 1951 redesignated to 8 cm pansarraket m/46A (8 cm prak m/46A).[13]
- 8 cm Pansarraket m/46B, English: 8 cm Armor rocket m/46B, in 1951 redesignated to 8 cm pansarraket m/46B (8 cm prak m/46B).[13]
- 8 cm Sprängraket m/46, English: 8 cm Explosive rocket m/46, in 1951 redesignated to 15 cm sprängraket m/46 (8 cm srak m/46).[13]
- 8 cm Övningsraket m/46, English: 8 cm Practice rocket m/46, in 1951 redesignated to 15 cm övningsraket m/46 (8 cm övnrak m/46).[13]
In 1952 Sweden had developed a whole line of indigenous rockets and started phasing out the RP-3. All models but the 8 cm prak m/46B disappeared before 1953.[15] The remaining 8 cm prak m/46B rocket were modified with new sloped fins around 1953. Around 30% of the fin surface area was removed. This decreased the chance of the fins breaking off during launch and also increased accuracy.[13] These fins were designated 8 cm fena m/46C and when equipped on the 8 cm prak m/46B the suffix changed to C, then becoming 8 cm pansarraket m/46C (8 cm prak m/46C).[15] The 8 cm prak m/46C remained in service until 1957.[14]
During its service life in the Swedish air force the rocket came to serve on several Swedish aircraft (see Aircraft using the RP-3 post the Second World War). To allow universal usage of the RP-3 the first and second generation of Swedish air to ground rockets used the same mounting system as the RP-3.[13][15][14]
Variants
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Royal_Air_Force_Coastal_Command%2C_1939-1945._CH13179_%28cropped%29.jpg/220px-Royal_Air_Force_Coastal_Command%2C_1939-1945._CH13179_%28cropped%29.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/2/2b/25lb_AP_No_2_rp-3.png/220px-25lb_AP_No_2_rp-3.png)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Hawker_Typhoon_with_RP-3_60_lb_F_rockets.jpg/220px-Hawker_Typhoon_with_RP-3_60_lb_F_rockets.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Royal_Air_Force-_2nd_Tactical_Air_Force%2C_1943-1945._CL3839_%28cropped%29.jpg/220px-Royal_Air_Force-_2nd_Tactical_Air_Force%2C_1943-1945._CL3839_%28cropped%29.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/5/55/Saab_b17_RP-3_rocket_%28cropped%29.jpg/220px-Saab_b17_RP-3_rocket_%28cropped%29.jpg)
Warheads
- Shell, 18 lb, HE
- 8 kg (17.6 lb) "high-explosive" warhead.[citation needed]
- Shot, 25 lb, AP, No. 1, Mk. I
- Armour-piercing (anti-submarine) warhead made out of hardened steel.[4]
- Shot, 25 lb, AP, No. 2, Mk. I
- Improved design over the Shot, 25 lb, AP, No. 2, Mk. I warhead made longer and pointier to increase penetration.[4]
- Shot, 25 lb, SAP, Mk. I
- Semi-armour-piercing" warhead; same design as the "Shot, 25 lb, AP, No. 2, Mk. I" but made out of mild steel and having the spigot fuzed together with the body.[4] By 1946 the design was obsolete and only used for advanced training.[4]
- Shot, 25 lb, Practice, Concrete, Mk. I
- Practice warhead 11+1⁄2 inches by 5 inches diameter made out of concrete,[16] meant to simulate shooting the 25 lb AP and SAP warheads.[4]
- Shell, HE, 60 lb, "F"., No. 1, Mk. I
- Fragmentation warhead for use against unarmoured vehicles and personnel. Converted from a 4.5 in (114 mm) howitzer shell with a Fuze, D.A., No. 899, Mk. I fitted to the nose, the whole warhead was 22 in (560 mm) long and weighed 50.5 lb (22.9 kg). The 4 lb (1.8 kg) TNT or RDX/TNT filling produced "heavy fragments" which caused damage at "considerable distance".[note 6][16][18]
- Shell, HE, 60 lb, SAP
- Semi-armour-piercing high-explosive warhead that existed in four primary variants:[16][4]
- Shell, HE, 60 lb, SAP, No. 1, Mk. I
- Shell, HE, 60 lb, SAP, No. 2, Mk. I
- Shell, HE, 60 lb, SAP, No. 1, Mk. II
- Shell, HE, 60 lb, SAP, No. 2, Mk. II
- Variants designated mark 1 (Mk. I) had a shell body that consisted of two parts that were screwed together, a body and a tip.[4] Variants designated mark 2 (Mk. II) had the aforementioned shell body and tip forged together as one piece.[4] Variants designated number 1 (No. 1) were fitted with a time delayed base fuze (Fuze, No. 865, Mk. I) that allowed them to penetrate into a target before detonating.[16][4] Variants designated number 2 (No. 2) were fitted with a none delayed base fuze (Fuze, No. 878, Mk. I) which made them detonate almost instantly on impact.[16][4]
- Shell, Practice, Concrete, 60 lb Mk. I
- Practice warhead 20 in long by 6 in diameter formed of concrete over steel reinforcing rods.[16] Used to simulate shooting the 60 lb SAP/HE warheads. This warhead could also be fitted with the "Smoke container, No. 1, Mk. I", which pressed on over front of the warhead and gave off a smoke signal on impact. The filling was 16 oz (450 g) of titanium tetrachloride.[4]
- Shell, HE, 60 lb, G.P.
- High-explosive general-purpose (Hollow charge) warhead, trials ongoing as of September 1946.[13] It could penetrate 198 mm (7.8 in) at any range.[19]
Rocket engines
The RP-3 rocket engine was updated a number of times during its lifespan, which gave rise to a number of variants. For example, it was necessary to modify the rocket engine's propellant charge in order to be able to use several types of warheads. Initially the rocket engine was only designed to use warheads up to 25 lb (11 kg), but when warheads up to 60 lb (27 kg) were introduced the propellant charge had to be modified in order to use them. Variants capable of carrying warheads up to 60 lb were then given the supplementary designation TH.[4]
- Aircraft rocket motor, 3 in., No. 1, Mk. 1
- The Mk. 1 engine had a 12.5 lb (5.7 kg) tubular-shaped cordite propellant charge.[20] The ignition cables are routed through the tubular propellant charge. This variant was suitable for use with 25 lb solid warheads.[20] It was not suitable for tropical climates (above 80 °F (27 °C))[21]
- Aircraft rocket motor, 3 in., No. 1, Mk. 1/TH
- TH variant of the Mk. 1 engine that could mount solid or shell warheads up to 25 lb. It could likewise not be used in hot climates.[21]
- Aircraft rocket motor, 3 in., No. 1, Mk. 2
- The Mk. 2 engine replaced the tubular propellant charge with a 11 lb (5.0 kg) cruciform (cross-shaped) propellant charge[20] through a different metal grid. The ignition cables where routed in one of the inner corners of the cruciform propellant-charge. This variant was only capable of mounting 25 lb warheads.[4]
- Aircraft rocket motor, 3 in., No. 1, Mk. 2/TH
- TH variant of the Mk. 2 engine that could mount warheads up to 60 lb.[4]
- Aircraft rocket motor, 3 in., No. 1, Mk. 3/TH
- The Mk. 3 engine replaced the two-pin ignition plug with a single-pin one[4]
- Aircraft rocket motor, 3 in., No. 1, Mk. 4/TH
- The Mk. 4 engines extended the ignition cables to allow for double hanging, were one RP-3 was mounted below another RP-3. During storage the extra length of the ignition cables was held in place by loose metal clips in the nozzle.[4]
Comparison
Warhead | Shot, 25 lb, AP, No. 1 | Shot, 25 lb, AP, No. 2 | Shell, HE, 60 lb, SAP | Shell, P., Concrete, 60 lb |
---|---|---|---|---|
Warhead diameter | 88 mm (3.5 in) | 152 mm (6.0 in) | ||
Engine diameter | 82.7 mm (3.26 in) | |||
Width with fins | 336 mm (13.2 in) | |||
Warhead length (including spigot) |
314 mm (12.4 in) | 378 mm (14.9 in) | 553 mm (21.8 in) | 608 mm (23.9 in) |
Engine length | 1,400 mm (4 ft 7 in) | |||
Overall length | 1,639 mm (5 ft 4.5 in) | 1,703 mm (5 ft 7.0 in) | 1,880 mm (6 ft 2 in) | 1,933 mm (6 ft 4.1 in) |
Weight of complete rocket with 17.2 kg (38 lb) engine |
28.5 kg (63 lb) | 44.6 kg (98 lb) | 44.4 kg (98 lb) | |
Warhead weight | 11.3 kg (25 lb) | 27.4 kg (60 lb) | 27.2 kg (60 lb) | |
Explosive charge | none | 6 kg (13 lb) TNT or Amatol 60/40[16] | none | |
Propellant charge | 5.2 kg (11 lb) cordite | |||
Performance | ||||
Propellant burn time at 15 °C (59 °F) |
1.6 s | |||
Thrust at 15 °C (59 °F) | 800 kgf (1,800 lbf) | |||
Maximum velocity | 380 m/s (1,200 ft/s) | 230 m/s (750 ft/s) | ||
Armour penetration | 88 mm (3.5 in) at 700 yd (640 m)[note 7][19] | not available | not available |
Aircraft use in the Second World War
As well as operational use, a number of aircraft were fitted with RP-3s on an experimental basis.
RAF and Commonwealth air forces
- Boeing Fortress Mk. II and IIA: (Coastal Command)
- Bristol Beaufighter Mk. VI, VIC, X and 20: (Coastal Command, South East Asia Command and Royal Australian Air Force, Pacific Theatre.)
- Consolidated Liberator B. Mk. III, VI: (Coastal Command.)
- de Havilland Mosquito F.B. Mk. VI: (Coastal Command, SEAC and RAAF, Pacific Theatre.)
- Hawker Hurricane Mk. IIE & IV: (Desert Air Force, RAF Second Tactical Air Force, SEAC.)
- Hawker Typhoon Mk. Ib: (2 TAF.)
- Republic P-47 Thunderbolt (USAAF used their M8 for this role instead, 6/aircraft)
- Vickers Wellington GR Mk. XIV: (Coastal Command)
Royal Navy Fleet Air Arm
- Fairey Firefly Mk. I
- Fairey Swordfish Mk. II, III
- Grumman Tarpon/Avenger Mk. I, II, III
- Hawker Sea Hurricane Mk. IIc (825 Naval Air Squadron)
- Hawker Sea Fury 807 Naval Air Squadron
Aircraft use post Second World War
The 3-inch RP continued to be used on RAF and RN aircraft in the ground attack role until replaced by the SNEB podded rocket (RAF) and the 2-inch podded RP (RN).[citation needed]
Post war operational use included the Malayan emergency, the Korean War, the Suez crisis, and the Radfan campaign.[citation needed]
RAF and Commonwealth air forces
- Bristol Brigand
- de Havilland Hornet
- de Havilland Vampire
- de Havilland Venom
- Gloster Meteor
- Hawker Hunter
RAAF, RAN
RP-3 rockets were used by Australian armed forces into the 1970s[23]
- Bristol Beaufighter
- North American P-51 Mustang
- de Havilland Vampire
- Fairey Firefly
- Gloster Meteor
- Fairey Gannet
- Hawker Sea Fury Mk11
- de Havilland Sea Venom
Royal Navy Fleet Air Arm
- Hawker Sea Fury
- Hawker Sea Hawk
- Supermarine Attacker
- Supermarine Scimitar
- de Havilland Sea Vixen (24 rockets total on 4 pylons, six per pylon);[24][25]
Swedish Air Force
- North American T-6 Texan (Sk 16 - 4 rockets total on 2 pylons)
- Saab 17 (B 17A - 4 rockets total on 4 pylons)
- Saab 18 (A & T 18B - 8-12 rockets total on 8-9 pylons)
- Saab 21 (A 21A-3 - 8 rockets total on 2 pylons)
- Saab 21R (A 21RA, RB - 10 rockets total on 1 pylon)
- de Havilland Vampire (J 28B, C - 8 rockets total on 4 pylons)
- Saab 29 Tunnan (J 29A, B, E, F - 8 rockets total on 8 pylons)
- Saab 32 Lansen (A 32A - 12 rockets total on 12 pylons)
See also
- M8 American air-ground barrage rocket, 4.5-inch (110 mm) calibre
- Land Mattress
- Tiny Tim, an American 11.75-inch (298 mm) calibre, 1,255-pound (569 kg) mass unguided rocket projectile
Notes
- ^ The possibility of the Soviets sending a team of engineers to help set up production of these weapons was a possibility in August 1941. However, the Soviet offer was withdrawn, in spite of British efforts at supplying a Wing of Hawker Hurricanes and training Soviet aircrew in their use.[citation needed]
- ^ a b c d Unless specified, data is from the Swedish Air Force 1950 manual "Bestämmelser för rakettjänst".[22] This manual uses original data collected in metric by the Royal Swedish Air Force Materiel Administration.[13] Compare with Imperial units data:[19][4]
- ^ In tests carried out by the A&AEE, dispersion (when aimed at a 20-foot (6.1 m) square target) was 13 ft 6 in (4.11 m) at 1,000-foot (300 m) range – equal to 3° to 4° aiming error.
- ^ A typical cruiser gun of the era, the 6-inch gun used on Royal Navy ships for instance, fired perhaps four or six 112-pound (51 kg) projectiles, while a fighter could fire eight 60-pound PR-3 in a single salvo.
- ^ also known as "motorized enemy transport", as opposed to "horse-drawn transport" (HDT)
- ^ The safety instructions advised against firing at less than 600 yd (550 m) range due to the risk to the aircraft.[17]
- ^ A flight time of 1.29 seconds from aircraft travelling at 350 ft/s (240 mph)
References
Citations
- ^ a b c d e Aeroplane Monthly June 1995
- ^ The Blitz Then and Now: Volume 3
- ^ "King's Collections : Archive Catalogues : BOWEN, Ivor (1902-1984)". kingscollections.org.
- ^ a b c d e f g h i j k l m n o p q r s AP 2802A volume 1: Aircraft rocket installations, sighting and ammunition, 1946-12-12 edition. Royal Air Force. 1946.
- ^ a b c Aeroplane Monthly July 1995
- ^ 3.5 in FFAR 5 in FFAR and HVAR Retrieved 6 March 2008
- ^ Burakowski, Tadeusz; Sala, Aleksander (1960). Rakiety i pociski kierowane [Rockets and guided missiles] (in Polish). Vol. Część 1 – Zastosowania (Volume 1 – applications). Warsaw: Wydawnictwo Ministerstwa Obrony Narodowej (Ministry Of National Defense Publishing House). pp. 556–557.
- ^ "GM.IIL", 429sqn.ca
- ^ a b c Shores and Thomas 2005, pages 245-250
- ^ Gerald Pawle, The Wheezers & Dodgers, Seaforth Publishing 2009 ISBN 978-1-84832-026-0 [page needed]
- ^ a b c d Moore, Craig (28 April 2016). "Sherman Tulip Rocket Firing Tanks". www.tanks-encyclopedia.com.
- ^ Fletcher, David (2008). Sherman Firefly. New Vanguard 141. Osprey Publishing. ISBN 978-1-84603-277-6.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z Sjögren, Sven. Raketbeväpning i svenska flygvapnet, FV raketbeväpning 1944-1954 [Rocket-armament in the Swedish air force, AF rocket-armament 1944-1954] (in Swedish). Stockholm, Sweden: Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration). p. 12.
- ^ a b c Flygvapnets raketmateriel, 1957 års upplaga [The Air Force's rocket-ordnance, 1957 edition] (in Swedish). Stockholm, Sweden: Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration). 1957.
- ^ a b c Flygvapnets raketmateriel, 1953 års upplaga [The Air Force's rocket-ordnance, 1953 edition] (in Swedish). Stockholm, Sweden: Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration). 1953.
- ^ a b c d e f g OP 1665
- ^ AP2802 Chapter 6 para 80
- ^ AP2802 Chapter 6 para 3-9
- ^ a b c Boyd, 2009
- ^ a b c AP2802 Section 3 Chapter 2, paragraph 19
- ^ a b AP2802 Section 3 Chapter 2, 22
- ^ Bestämmelser för rakettjänst [Provisions for rocket-use] (in Swedish). Stockholm, Sweden: Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration). 1950. p. 2.
- ^ "Ordnance Information Sheet: Air-Launched Rocket - 3 Inch/60 Pound" (PDF), Defence Unexploded Ordnance Website (Rev 02. ed.), Australian Government, March 2015
- ^ "Ground Attack". www.seavixen.org.
- ^ "De Havilland's twin-boom, twin-engine jet fighter for the Fleet Air Arm". www.baesystems.com.
Bibliography
- Ramsay, Winston (editor). The Blitz Then and Now; Volume 3. London, UK: Battle of Britain Prints International Limited, 1990. ISBN 0-900913-58-4
- Shores, Christopher and Thomas, Chris. Second Tactical Air Force Volume Two. Breakout to Bodenplatte July 1944 to January 1945. Hersham, Surrey, UK: Ian Allan Publishing Ltd, 2005. ISBN 1-903223-41-5
- Webb, Derek Collier. "Rocket Attack part 1". Aeroplane Monthly Volume 23, No 6, Issue No 266. June 1995.
- Webb, Derek Collier. "Rocket Attack part 2". Aeroplane Monthly Volume 23, No 7, Issue No 267. July 1995.
- Ordnance Pamphlet 1665 British Explosive Ordnance Part 3 - Chapter 2 High-Explosive Rockets 3-in. Aircraft Rocket (Service)
- Boyd, David (1 January 2009), "Airborne Rockets Used By the British During WWII", WWII Equipment
- A.P. 2802A volume 1: Aircraft rocket installations, sighting and ammunition (RAF) (PDF). Royal Air Force. July 1944.
Amended to 12 December 1946
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)