Tiberius Aerospace company reported that its 155mm TRBM 155HG Sceptre shell with ramjet liquid rocket engine launched its engine in flight during recent live-fire tests. Most likely, tests conducted since late 2025 tested only the design, without functioning engine.
Along with this announcement, the company published video from this test. One can notice the shell flying horizontally, in other words, the ability of the engine to work after initial overload of 18,000g during firing was tested.
The video also shows a certain sabot flying immediately behind the shell, which pushes the TRBM 155HG Sceptre out of the barrel under powder charge action. Interestingly, the ramjet liquid rocket engine turns on already several meters after exiting the gun barrel.
Development of TRBM 155HG Sceptre first became known only in May 2025. Regarding characteristics, maximum range of 140-160 km is announced, as well as speed in initial stage up to Mach 3.5 (4,290 km/h).
As noted above, this shell’s caliber is 155mm, while its length is 1.55 meters, which is indeed quite a lot.
This ramjet liquid rocket engine can use three fuel types at once for operation: diesel, as well as JP-4 and JP-8 aviation fuel. Shell weight when firing is 47.5 kg, but despite this, only 5.2 kg may fall on the warhead.
For comparison, in standard 155mm M107 shell this is over 6.6 kg. Moreover, such a small warhead is compensated by high accuracy of 3.5 meters, achieved thanks to inertial system and GPS. Also, to increase armor penetration, TRBM 155HG Sceptre can be equipped with tungsten alloy cap.
The company announces that despite such characteristics and presence of ramjet liquid rocket engine, TRBM 155HG Sceptre’s cost will be about $52,000 not including warhead, fuel, as well as detonator.
Additionally, a special programmer costing $15,000 and refueling station costing another $52,000 are necessary for operation. All this is still significantly less than “golden” M982 Excalibur, which in 2023 cost up to $178,000.
At the same time, firing TRBM 155HG Sceptre shells can also be conducted from any 155mm gun, without need for any additional modifications.
Britain is investing in testing and development of these TRBM 155HG SCEPTRE reactive 155mm shells. Now it’s not excluded they may end up in Ukraine.
Although, considering only now engine testing of this shell has passed, there’s still quite a lot of time until development completion and serial production start. Most likely, the next step will already be long-range firing with guidance system verification.
