Sholef (Slammer) 155mm Self-propelled howitzer
It is the integration of a small protected crew with a highly mobile and autonomously operative artillery piece, carrying a 155 mm, 52 cal. cannon, fully automatic ammunition loading system, capable of the fastest fire rate reaching ranges of up to 41 km, which made the Slammer as effective as a regular artillery battery.
The self-propelled artillery of Israel leaves much to be desired. There are several hundred American-made M109A5 combat vehicles in service with characteristics that are far from fully up-to-date. In addition, some of the existing self-propelled guns will soon celebrate the half-century anniversary, and over the past decades have managed to work out almost the entire available resource.
The fate of foreign-made self-propelled guns became apparent in the late 1970s. Operated for about ten years, these machines had become obsolete morally and physically, and so there began a search for a replacement for them. Using ready-made units and some new devices, it was planned to get a combat vehicle with the highest possible technical and operational characteristics. Certain features of the technical specifications allowed even to count on world leadership in the field of self-propelled artillery.
The development of the new project was entrusted to the Soltam company, which had already accumulated considerable experience in the creation and production of artillery systems of various classes. In addition, the project on the rights of subcontractors should have been involved and other companies that produce these or other systems. They were required to prepare the required chassis, instrumentation, etc.
Sholef was a 155mm 52-caliber self-propelled howitzer, equipped with an automatic loading system. Based on the chassis of the Merkava Mark 1 tank [not the Merkava II and III as reported by some sources]. It was development in 1970s before the Merkava Mark 2. It offered a better self-propelled howitzer to the IDF as it had better performance over the older M109. In the foreseeable future, the Mk I model tanks were planned to be replaced by newer Mk II, as a result, a significant number of tracked chassis could be released. The use of used tank chassis allowed to significantly reduce the cost of the program of mass production of SPH, as well as accelerate the production of such equipment.
The Merkava hull has a feature which is unique among other main battle tanks - the engine is at the front of the hull and the crew compartment to the rear. This structure of the Merkava is commonly used by self-propelled artillery, and therefore idealy suited to such a modification. Other such efforts to adopt conventionally designed main battle tanks to self propelled artillery have been rather less successful.
The project "Sholef" / Slammer meant the preservation of the existing chassis. On each side of the hull there were six double rubberized road wheels. Suspension rollers - individual springs on the system Christie. Two front and two rear rollers had additional hydraulic shock absorbers. An interesting feature of the chassis was the use of five supporting rollers on each board. Driving wheels were placed in the front of the hull, guides - in the stern.
To accommodate large and heavy weapons, as well as related equipment, it was necessary to develop a new turret. She received a welded cap of complex shape. Relatively thin armor was used, able to protect only from bullets or splinters. The tower had a tapering frontal part with a large opening for the withdrawal of guns, consisting of two main elements of the board, as well as aft with beveled side parts. In the center of the forage sheet was a large hatch, next to which placed the automatic supply of ammunition. The vehicle was equipped with internal fire protection system.
The barrel features a gas extractor and a double baffle muzzle brake. During maneuvers, the weapon is arranged in a travel position with a guard that secures it to the armor hull, this is mounted on the front tip of the glacis, and can be remotely operated from the troop compartment, inside the hull.
For self-defense, the crew had a large-caliber machine gun M2HB mounted on one of the hatches in the roof of the tower. This total ammunition included 1000 cartridges. In the framework of further development, self-propelled guns could get other means of protection, such as smoke grenade launchers or thermo smoke equipment.
The regular crew consisted of four people. In the front compartment of the housing control housed a driver. His workplace fully corresponded to the base model used on the Merkava tank. Access to the control compartment was provided by a roof hatch. The commander, gunner and loader were in the fighting compartment. They used two hatches in the roof and aft hull of the hull. Workplaces inside the turret were equipped with all the necessary equipment to monitor the work of weapons and other systems.
Taking into account local conditions, the habitable compartment received an air conditioner. Later, when using newer chassis, the self-propelled gun could receive a collective protection system against weapons mass destruction. In case of long-term combat work at a distance from the base or camp, the car was equipped with means for heating food.
The Sholef needs only 15 seconds to go into firing mode, and it was possible to direct fire, even while driving. The Sholef used standard NATO 155 mm ammunition. While the Sholef can store 75 projectiles only 60 projectiles stored internally and are ready to be used. The 155 mm 52-caliber gun was specially made by the Soltam company. Its maximum rate of fire is 9 rounds per minute with range over 40km when using automatic loading system. It can be fired automatically and manually. One of the unique futures of the Sholef is that it can direct fire on the move. The addition of a support bracket for the barrel, was folded when the Sholef wasn’t in use.
Sholef required only 4 crew members to operate. Particular attention in the Scholef project was given to fire control tools and gun maintenance automation. Due to this, as a result, it was possible to obtain very high combat characteristics. It used GPS and inertial navigation and firing ERFB-BB projectile to 40,000 meters. Automatic loading allowed to make the first three shots in just 15 seconds. After that, the rate of fire reached 9 rounds per minute. The high rate of fire is achieved by using the ammunition supply on board or stackable ammunition on the ground, close to the Sholef's area of ??operation. The load / reload cycle is operated by only two crew members in the turret, with the commander serving as the computer operative and the loader in the cargo bay.
While only two prototypes where ever made and unveiled in 1984 and 1986, the Sholef did not enter production as it was too expensive. IDF decided to upgrade its M109 howitzers instead, as it was cheaper to upgrade the M109 than produce the completely new Sholef. The Merkava 1 and the Solef shared many similar components ans this made the Sholef cheaper as these components were already in serial production. With noticeable advantages over the mainstream M109A5 in basic performance, the “Sholef” was almost twice as expensive. Even the use of serial chassis borrowed from decommissioned tanks did not allow to reduce the cost to acceptable values.
