Thunder-1 (Raad-1) Based on on a Boragh chassis and 2S1.

In May 1996, it was revealed that the Defence Industries Organisation (DIO) of Iran had developed and successfully tested a 122 mm self-propelled artillery system called Thunder-1.

Early in 2002, it was revealed by Iran that its 122 mm Raad-1 self-propelled gun/howitzer (SP/GH) was then in quantity production by the Iranian Defence Industries Organisation (DIO), Armour Industries Group.

This is in service alongside the larger Raad-2 155 mm SP/GH that is covered in a separate entry. The Raad-1 has also been referred to as the Thunder-1.

The Raad-2 155 mm and Raad-1 122 mm have been offered on the export market but as of early 2008 there were no export sales of these weapons.

Thunder-1 is based on a new high-profile full-tracked chassis with the engine compartment and driver being at the front and the fully enclosed 122 mm turret mounted at the rear.

The turret appears to be identical to that fitted to the Russian 122 mm 2S1 self-propelled howitzer which was first fielded in 1971, with more than 10,000 systems being built.

As well as being built in Russia, the 2S1 was also built in Bulgaria and Poland for the home and export markets. Russia also sold 122 mm 2S1 turrets to Romania which then integrated them onto a locally designed and built chassis to make the Model 89 122 mm self-propelled howitzer, but this was never exported and only 42 were built.

At the present time it is not clear if the 122 mm turret of the Thunder-1 is coming from abroad, which is possible given the surplus of these systems in a number of Eastern European countries, or if it is being manufactured in Iran. As the 2S1 turret is of welded steel construction, it could easily be made in Iran.

Iran is believed to have taken delivery of at least 60 122 mm 2S1 systems in recent years and it is possible that the turret used on Thunder-1 could have been taken from one of these as an expedient before production of the turret gets under way in Iran.

The 122 mm 2S1 is armed with a 122 mm 2A31 ordnance fitted with a fume extractor and a muzzle brake which is itself a modified version of the 122 mm ordnance used in the 122 mm D-30 towed artillery system which has been manufactured in Iran by the Defence Industries Organisation (DIO) for some years. When travelling, the 122 mm ordnance of the Thunder-1 is held in a travel lock fitted at the front of the hull.

It is now known the 122 mm ordnance of the Thunder-1 self-propelled artillery system is manufactured by the Hadid facility of the Iranian Defence Industries Organisation and is designated the HM51.

The ordnance for the 155 mm Thunder-2 self-propelled artillery system, covered in detail in a separate entry, is designated the HM44. This could indicate that development and/or production of the Thunder-2 self-propelled artillery system started first.

Iranian sources state the HM51 has a calibre length of 32.7 and weighs 1,440 kg. It is fitted with a fume extractor and a double-baffle muzzle brake. Turret traverse is 360º with weapon elevation from -3 to +70º. Maximum rate of fire is stated to be 4 to 5 rounds per minute.

To enable the 122 mm Thunder-1 to have a higher rate of fire it is understood it has been fitted with an automatic loading device of some type. This could well include a flick rammer which would also enable the weapon to be loaded at high angles of elevation as well as increasing its rate of fire. The flick rammer would probably flick the projectile with the charge being loaded manually.

Maximum range of Thunder-1 firing a standard 122 mm high-explosive projectile is 15,200 m. The Russians did develop a Rocket-Assisted Projectile (RAP) for the 2S1/D-30 with a maximum range of 21,900 m, but as far as it is known this has not so far been made in Iran.

No technical details of the Thunder-1 are available although it has a maximum road speed of 65 km/h and is fully amphibious, being propelled in the water by its tracks. The large size of the hull could be influenced by the requirement to be amphibious without significant preparation.

The suspension is of the torsion bar type with the upper part being covered by a rubber shroud. The roadwheels are similar to those of the M107/M110 self-propelled artillery systems supplied to Iran many years ago. Iran is understood to have been making roadwheels for the M107/M110 for some years.

The 122 mm D-30 is the most widely used weapon of its type and has also been made under licence or copied by such countries as China, Egypt, Iran, Iraq and Yugoslavia.

The Iranian DIO has been making the 122 mm separate loading ammunition for some years, including high-explosive, smoke and illuminating natures.

Iranian sources claim that the Thunder-1 features `rapid firing ability, excellent accuracy, first class mobility and computer-controlled fire'. It is also claimed that Thunder-1 has a laser range-finder and onboard computer. This could also be fitted to the 155 mm Thunder-2 self-propelled artillery system covered in a separate entry.

There are no known variants of the Raad-1 122 mm self-propelled artillery system although the design of the chassis is such that it can be used for a wide range of other applications. The Boraq chassis is being used for an increasing number of battlefield roles, including ammunition resupply vehicle and mortar carrier. Details of the Armoured Ammunition Carrier are given in the entry for the Boraq APC. This could be used to support 122 mm and 155 mm self-propelled artillery systems, as well as towed artillery systems.