Boeing-Nammo Ramjet 155 rocket launcher being tested
Projectile model at Eurosatory 2018
Over the past few years, the American company Boeing, in collaboration with the Norwegian Nammo, has been developing a promising long-range artillery projectile. To date, the Ramjet 155 project has passed the early stages, and test firing is now underway. Experienced projectiles demonstrate design characteristics and give rise to positive forecasts.
Initiative, cooperation and contracts
In 2018, at the Eurosatory exhibition in France, Nammo for the first time presented the concept of an active-rocket projectile with an increased firing range. The main feature of this concept was its own ramjet engine, which made it possible to significantly increase the firing range compared to conventional ammunition. So, it was argued that in a standard caliber of 155 mm, a range of up to 140-150 km can be obtained.
In the future, the project was developed. In June 2019, Nammo and Boeing, represented by Phantom Works, signed an agreement to further jointly continue the development of the new Ramjet 155 projectile. The companies then applied to participate in the new Pentagon program to develop the XM1155 Extended Range Artillery Projectile (ERAP) projectile. Already in July of the same year, they received an official order for design work as part of the competitive stage.
The next two years were spent on completing the necessary research and determining the final shape of the new projectile. In the spring of 2021, the customer evaluated the Nammo / Boeing project and compared it with the proposals of other program participants. As a result, Ramjet 155 was allowed to the next stage. Its goal was to complete the design, as well as the production and testing of experimental projectiles.
Projectile on trials
Recently, development companies reported that for a long time various tests and tests were carried out as part of a new project. Both individual units and the entire projectile on the stand were tested. The total number of such events exceeds 450.
In addition, full-fledged shooting has already begun. The first tests of this kind took place in January 2022 at one of the Norwegian test sites. The second series of test firing was carried out in March. It is curious that such tests, their results and successes were reported to Nammo and Boeing with a long delay - in May.
All the details of the January and March tests were not given. However, it was reported that the experimental projectiles used the ramjet in flight and coped with the tasks. It was also possible to confirm some of the calculated characteristics. In addition, the progress in the development of the engine for the projectile is shown, and this component of the project does not face any difficulties. In this context, the shootings of the beginning of the year were called promising.
Also, tests have shown that the Ramjet 155 product does not have a significant negative effect on the tool used. The resource, survivability and performance of the artillery system do not suffer. This is a separate reason for optimism in terms of the future introduction and use of new projectiles.
The next tests took place at the end of June, although they were reported only in August. This time, firing was carried out at an unnamed increased range. The purpose of the tests was again to test the operation of the ramjet and to develop the design of the projectile as a whole. The interaction of the ammunition with the gun was also clarified. All components of the artillery complex coped with their tasks and confirmed the design characteristics.
June tests are called the most important event both for the Ramjet 155 project and for cannon artillery in general. Nammo and Boeing are confident in the great promise of the ramjet projectile concept, and the firings are said to prove them right. In addition, the management of the development companies did not forget to mention that the Pentagon simply needs a new projectile.
New solutions
The Ramjet 155 is a specially designed artillery projectile with an extended range. It is intended for use with 155-mm artillery systems, both existing with 39-caliber barrels, and with promising 58-caliber ones. At the same time, the projectile will show the best characteristics with a longer barrel.
Demonstration of design and flight characteristics
The projectile from Nammo and Boeing has a caliber of 155 mm and a length of about 1 m. Outwardly, it looks like standard projectiles, but instead of a pointed head part, a frontal air intake is provided. Inside the latter is a spindle-shaped central body, which occupies about half the length of the body. On the side surface of the hull there are rudders that are laid out in flight, and an engine nozzle is provided at the bottom.
Part of the volume of the hull is given over to the supersonic ramjet. Compression of the air in front of the engine is provided by the high airspeed and the configuration of the intake device. The engine runs on solid fuel in the form of a cylindrical block with a longitudinal channel. In the available volume, you can place a charge with a burning time of up to 40-50 s.
The projectile is designed to hit targets with known coordinates. To do this, it is equipped with a satellite navigation system and controls. Correction of the trajectory in flight is carried out aerodynamically, using a set of rudders. The main control equipment is placed inside the central body of the air intake. The warhead of an unknown mass is located in the same building.
The exact characteristics of the Ramjet 155 product have not yet been reported. At the same time, the terms of reference for the ERAP project provide for a range of at least 100 km when using promising long-range guns. Nammo, in turn, talked about the fundamental possibility of creating a 155-mm projectile with a range of up to 150 km.
Shot with an experimental projectile, June 2022
Next stage
As follows from the latest reports, Nammo and Boeing Phantom Works have completed the development and factory testing of a new projectile. The design characteristics have been confirmed, and now the project can move on to the next stage. The finished product Ramjet 155 will be presented to the customer, and he will conduct his own tests.
The Pentagon will have to re-confirm the declared characteristics, as well as determine their compliance with the terms of reference of the program. In addition, the customer will have to compare the Ramjet 155 with other competitive developments and choose the most successful sample. This projectile, if necessary, will undergo a fine-tuning process and will be recommended for adoption.
Judging by the available data, the joint development of Boeing and Nammo has every chance of winning the competitive part of the program and entering service. Whether it will be possible to obtain such results will become known later. However, we can already say that the two companies have managed to implement an interesting idea that previously existed only in the form of technical proposals.
The Ramjet 155 has a distinctive design and compares favorably with conventional rocket-propelled projectiles. Instead of a gas generator or a rocket engine, it carries a "full-sized" ramjet engine with increased thrust and longer operating time. With their help, the projectile gets more acceleration, and with it an increased flight range.
Salvo firing of Ramjet 155 products as imagined by an artist
Despite the specific layout, it was possible to integrate controls, a steering system and a warhead into the projectile. In terms of the size and weight of the warhead, it should lose to traditional ammunition, but guidance tools are able to compensate for this disadvantage.
At the same time, the Ramjet 155 product turned out to be complex and expensive. It is unlikely that its cost will be lower than that of existing adjustable projectiles. However, it should be borne in mind that the high price is associated with special fire capabilities that are simply absent from existing ammunition. Therefore, the financial component of the project is unlikely to be a reason for criticism.
Work continues
The current program to develop new munitions is a key component of the Pentagon's larger plans. At the same time, the development of 155-mm guns for existing and advanced projectiles, as well as self-propelled guns with such weapons, is underway. Some of the main components of the future long-range artillery complex have already been tested and confirmed some of the characteristics.
Apparently, over the next few years, the Pentagon will complete this program, and new self-propelled guns with improved performance will go into service with ground artillery. Due to which projectile the firing range will be increased, it is unclear. According to the latest news, this niche can be occupied by the American-Norwegian Ramjet 155. Of course, if it manages to bypass competitors and confirm compliance with customer requirements.
Information