In an unprecedented move, Type 003 Aircraft Carrier Fujian (Carrier 003) conducted tests of its electromagnetic catapult within the harbor basin, displaying an astonishing level of force. Images shared by netizens on social media reveal a large circle of splashes approximately 100 meters in front of Carrier 003, accompanied by a mist of water in the air. Without delving into extensive explanation, this essentially captures the moment when the electromagnetic catapult launched the testing vehicle.
Remarkably, the passenger on the aircraft was exceptionally fortunate, managing to capture this scene precisely at the moment of pressing the shutter. Formerly, concerns were raised regarding the practicality of conducting catapult tests within the harbor basin, given the limited distance of less than 300 meters in front of the basin. The potential risk of the launch vehicle flying out of the basin and causing a significant incident was a point of consideration. However, it is now evident that these concerns were misplaced, as Carrier 003 indeed performed electromagnetic catapult testing within the harbor basin. This not only reflects confidence in the catapulting capability but also demonstrates a high level of assurance in controlling the launch intensity.
Isn’t the catapult designed for launching carrier-based aircraft? How did it end up launching cars? We can explore the preparations required for electromagnetic catapult-equipped carriers by looking at the U.S. Navy’s USS Ford.
One major technical feature of the USS Ford aircraft carrier is the use of electromagnetic catapults. Compared to conventional steam catapults, electromagnetic catapults offer numerous advantages, including smaller size, lighter weight, fewer system components, greater launch capability, a wider range of launch adjustments, higher usability and feasibility, and lower cost. Therefore, electromagnetic catapults are considered the optimal replacement for steam catapults.
However, from the construction, outfitting, sea trials, and commissioning of the USS Ford, it becomes apparent that electromagnetic catapults are not as straightforward as envisioned. Construction-wise, electromagnetic catapults have high requirements, especially considering that electromagnetic leakage can severely interfere with onboard electronic equipment, potentially causing damage. Tight measures are required to minimize electromagnetic leakage.
Another challenge is controlling the deformation of the electromagnetic catapult track to a minimum to avoid malfunctions such as getting stuck. This involves aspects of electromagnetic catapult design, manufacturing, installation, and construction. Even after installation, stresses generated by the ship’s hull and deck can deform the catapult track, requiring measures for control and elimination – a lesson learned from the USS Ford’s experience.
Once the electromagnetic catapult is installed, simulated tests of aircraft launches are conducted using specially designed “cars” to validate the catapult’s practical performance. Due to cost and safety considerations, these initial tests do not involve launching actual aircraft but rather use specialized “cars” for simulation.
These cars, known as launch test weighted cars, are typically painted orange-red for easy observation and recording, as well as easy retrieval after entering the water. The cars have a box-like structure with internal provisions for ballast. Both the front and rear of the car have curved structures to enhance the overall structural strength. Additionally, a deceleration board is installed on one side of the car’s front to prevent excessive movement upon entry into the water, aiding in positioning for retrieval.
Four wheels are installed beneath the launch test weighted car, and during launch, it is secured to a dedicated towing cable in front of the car, attached to the catapult slider. Once connected, it is ready for launch. However, as the car lacks aerodynamic flight capabilities, it can only fly a short distance from the deck before landing in the water. For safety, a 200-meter area around the carrier’s launch direction must be clear of any vessel activity.
After being launched into the water, the weighted cars are retrieved by tugboats and prepared for the next round of launches. These weighted cars are not disposable; in fact, a batch of them can be used for many years, making them suitable for servicing multiple carriers.
Launch tests follow a progressive process, starting with small-weight launches and progressing to larger weights. According to U.S. Navy experience, during launch tests on the USS Ford, the lightest weighted car was 7,900 pounds (approximately 3.58 tons), while the heaviest could reach 79,000 pounds (approximately 35.8 tons). This weight range provides ample redundancy, as the heaviest carrier-based aircraft, such as the F-35C, have a takeoff weight of around 32-34 tons, and the simulated upper limit already exceeds the F-35C’s maximum takeoff weight.
The future aircraft complement for the Fujian carrier includes J-15B, J-15D, J-35, and carrier-based early warning aircraft. As these fixed-wing aircraft require electromagnetic catapults for takeoff, and considering their maximum takeoff weight may exceed 30 tons, the electromagnetic catapults on the Fujian carrier need to handle weights exceeding 30 tons as well. The weight of the test weighted cars must match these requirements.
The cars are launched from the electromagnetic catapult, splash into the water, and the testing system collects data for analysis. This iterative process evaluates the actual performance of the electromagnetic catapult, ensuring alignment with theoretical calculations. If there is a significant deviation between the launched data and theoretical calculations, investigations are carried out for corrections and improvements. To make the data as realistic as possible, these tests are conducted multiple times, consuming substantial human and material resources and lasting for an extended duration.
Launches in a stationary state cannot fully reflect the complete performance of the electromagnetic catapult; it serves as a rehearsal for sea trials. During carrier sea trials, there are also tests involving catapult launches at sea, evaluating the electromagnetic catapult’s real-world performance. Again, due to cost and safety considerations, sea trials use simulated launch test weighted cars instead of actual aircraft. These tests include launches on calm seas and under high sea conditions, simulating real-world combat scenarios to the maximum extent.
There are reports that the USS Ford conducted simulated weighted launches in the vicinity of Norfolk for up to a year. However, after entering service, it returned to Norfolk for additional simulated launch tests, indicating that issues identified during previous tests needed significant improvement before further launch trials.
Only after completing these steps does the electromagnetic catapult proceed to actual aircraft launches. Initially, launches are conducted on calm seas, followed by launches under high sea conditions. According to information from the U.S. Navy, the initial performance of the USS Ford’s electromagnetic catapult was not ideal, with a major issue being the lack of reliability.
According to the U.S. Navy, the USS Ford experienced 10 failures in the first 700 catapult launches, averaging one failure every 70 launches, a far cry from the design target of one failure every several thousand launches. Efforts were made, and the USS Ford managed to improve the rate to one failure every 200 launches, a significant improvement but still falling short of the design target.
Additionally, despite having four electromagnetic catapults, the USS Ford’s catapults lacked independent power sources. Consequently, their current-driven systems couldn’t isolate operations like traditional steam catapults. If one failed, all catapults had to stop for power-off maintenance, further reducing system reliability.
Despite substantial investment and extensive testing, the performance of electromagnetic catapults on the USS Ford fell short of expectations even after being put into service, requiring ongoing refinement and improvement. Lessons learned from this experience can be valuable for the Fujian carrier, which represents the first use of electromagnetic catapults in the People’s Liberation Army Navy. While the design may be more reasonable compared to the USS Ford’s catapults, thorough testing is essential to expose issues early and facilitate corresponding improvements.