With air defense as its primary mission, the Kasal class had to be equipped with high-powered anti-aircraft radars, anti-aircraft warfare systems, and heavy area defense missile launchers. Both the weight of the equipment and the amount of deck space taken up by the Kasal class increased further, which led to a high degree of space and weight constraints on the basic design of the general purpose destroyer from the F-70; for this reason, the Kasal class had to make a number of sacrifices. First, in terms of hull materials, the original design of the Casal class was finalized in 1977, using an aluminum alloy superstructure; then, based on the lessons learned from the 1982 war on the Isle of Man, the surface ships built by various countries, most of them used steel to replace the flammable and easily melted aluminum alloy materials.
After the 1982 war on the Isle of Man, the French Navy modified the design of the three unfinished Georges Léger-class destroyers to steel superstructures; however, the construction of the first Casal-class ship, which began after the end of the war on the Isle of Man, was saturated with loads due to the complexity of the equipment (the weight of all the ship's weapons systems, ammunition, and fuel had already exceeded one-third of the displacement of the entire ship), and the ship had to continue to use a lighter weight aluminum alloy as the superstructure. The lighter weight aluminum alloy was used as the superstructure material. In order to compensate for the inherent limitations of the lower damage resistance of the building materials, the Kassar class is equipped with sophisticated damage control and fire fighting systems as well as nuclear, biological and chemical protection equipment (including spray washers) to make up for this.
The Kassar's superstructure is sloped and rounded to partially reduce the RCS, and the bow has been cut down 5 degrees to provide a negative saddle arc to increase the angle of fire for the bow gun. The second deck of the hull has a passageway running along the centerline of the hull, which can be used by the ship's personnel to quickly move around the ship and reach the battle stations. In a nuclear, biological or chemical environment, the ship can remain sealed and operational for up to 24 hours. Compared to the French ships in the past, the Casal class has a better livability, the soldiers cabin is every 6 people, the military/non-commissioned officers cabin according to rank and seniority, the highest class is 2 people a room, and the ship related to the dining room, kitchen, warehousing, medical and other living service area space is more than the past. With a complement of 225 personnel (19 officers), the Kassar has a total of 251 berths, with extra space for Marines, Special Forces or Command staff. Excess weight also occurs in the power system, George Legge class originally used in line with the current trend of composite gas turbine or diesel power system (CODOG), gas turbine has a fast start, fast acceleration, light weight, thrust-to-weight ratio and other advantages, is a new generation of surface ships of the mainstream power; however, in order to cooperate with the gas turbine, the ship needs to set up a large air intake, the intake in front of the need for a piece of space However, in order to work with the gas turbine, a large intake port is required on the ship, and a space in front of the intake port is needed as a buffer, and nothing can be installed to enable the gas turbine to draw in a sufficient and stable airflow, which will take up valuable space on the ship. In order to save the space for the air intake, the Casals gave up the high-performance gas turbine and adopted a composite diesel engine and diesel powertrain (CODAD), becoming the first surface combatant in the French Navy to use all-diesel power.
Cassar-class main engine for the four SEMT 18-cylinder PA6 V 280 BTC diesel engine, dual-axis fixed-pitch propeller propulsion, the main engine operating speed of 1050 revolutions per minute, the total power of 43,200 horsepower, placed in two completely independent cabin (accounting for the length of the ship 40m), the two compartments at the same time rupture into the water of the chance of very low, can increase the rate of survival; as for the ship's electric power is The maximum speed of the Kassar class was 29 knots, while the maximum speed of the French nuclear-powered aircraft carrier Charles de Gaulle was only 27 knots, so there was no problem in matching. At 24 knots, the Casals had a range of 4,800 nautical miles, or 8,200 nautical miles at 17 knots, allowing them to operate for 30 days at sea. Initially, the class was equipped with a Thompson-CSF Jupiter 2D long-range air search radar and a DRBV-15 Sea Tiger planar search radar; the DRBV-15 was supposed to be a temporary replacement, and was immediately replaced by the new DRBJ-11 ARABEL 3D multifunctional phased-array radar in 1992. The ARABEL radar is X-band and has a short range but high accuracy, and its high rotational speed (60 rpm) facilitates precise tracking of approaching targets. The ship is equipped with two Racal DRBN-34A (Type 1229) I-frequency navigation radars, one of which is located at the front of the hull, mainly for navigation, and the other at the rear of the hull, mainly for helicopter control.
The class is equipped with two U.S.-made AN/SPG-51 illuminating radars to guide standard SM-1MR anti-aircraft missiles, as well as the DCN's CTMS optical/radar firing control system (including the IBC 1A Piranha II TV/infrared tracking system, the SAGEM DIBV-1A infrared target tracking system integrated with the search radar, the Thomson DRMS for the gun, and the Thomson DRS for the gun control). Thomson DRBC-32/33 I-frequency gunnery radar for guidance and control of the ship's guns, and the CSEE Najir optical command system. Electronic warfare systems for this class include the Dassault (now Thales Optrosys) ARBB-33 electronic countermeasures system (H/I/J frequency), the Thomson-CSF (now Thales) ARBR-17B electronic support system (French version of the DR-3000S), two CSEE (now EADS) AMBL-1B Dagaie jamming filaments with two Sagaie AMBL-2A ten-unit jamming projectile launchers, in addition to a U.S.-made AN/SLQ-25 torpedo countermeasures system. The Kassar's main air defense arm is a US-made MK-13 single-armed missile launching system located between the hangar and the illuminating radar, which was transplanted from the four air-defense version of the Type 47 destroyer, but with 40 missiles instead of the original Tartar and the more advanced standard SM-1. The installation of this device is sandwiched between the fore and aft superstructure, and the angle of fire is limited, which is not ideal. The first two Casals were MK-13s, and the French Navy had initially planned to retrofit the last two Casals with vertically-launched Aster-series anti-aircraft missiles, but construction of these two was canceled.
In terms of close-in air defense, the Kassar class has a French six-unit Sadral (Système d'Auto-défense Rapprochée Anti-aérienne Léger) missile installation on each side of the hangar, which is a sea-based derivative of the Army's Northwesterly missiles to intercept approaching enemy aircraft and missiles. Each Sadral is equipped with six standby missiles in addition to a reserve of about 13 each. Under normal circumstances, the Sadral system is commanded by the combat system and is fully automated for engagement, but can be converted to manual operation if necessary. During tests in October 1990, the Sadral air defense missile system on the Kassar successfully fired two Northwest Wind air defense missiles to shoot down a sea-skimming target.
The Kassar-class ships are armed with a Model 1968 CADAM 100mm 55x automatic gun with a rate of fire of up to 78 rounds/minute on the bow, which provides both anti-aircraft and anti-surface capabilities. Other weapons on board include eight MM-40 Flying Fish anti-ship missiles (replaced by the new MM-40 Block 3 in 2006), two Oerlikon 20mm guns (720 rounds/minute, 10km range) on both sides of the 02 deck of the superstructure, two 12.7mm machine guns, two KD-59E stationary lightweight torpedo devices (with ten ECAN L5 Mod 4 light anti-submarine torpedoes, equipped with active/passive sonar seeker, speed 35 knots, maximum range 10km, capable of attacking targets up to a depth of 550m, with a 150kg high-explosive warhead in the combat section).