FTX-2 External Fuel Duct (stock). Flexible?

[QvestionAnswerNeeded]

Hello, this is my first time using the forum. I have a question regarding the FTX-2 External Fuel Duct. 

I’m planning a stock mobile artillery unit, and the weapon will be Tiny fuel tanks. A Reliant liquid fuel engine will propel the fuel tanks

a (hopefully) long distance, but since the shells drop in through the top, the Reliant needs to recoil. Also this is preferable, since I think the engine might break the turret or the chassis. So, I was thinking of using External Fuel Ducts to restrain the engine on firing. But this requires the fuel ducts to be flexible . Are these fuel ducts flexible?

[MaianTrey]

If you're moving the engine separate from the rest of the craft, it will have to be 2 separate craft. You can build them as one and then decouple them, but for any movement to happen it has to be separate. When you separate them, any fuel lines and struts that you have connected will disconnect. Fuel lines and struts don't stay connected to separate crafts.

[QvestionAnswerNeeded]

Oh... really? I saw a video of someone using FTX-1s to restrain a Thud liquid fuel engine while it fired Little RCS ports.

Also, the firing mechanism will be connected to a thing that can adjust its angle for firing...

[Xd the great]

Mods will help here, if you wanna use them...

Bdac has no artillery guns, but it has modular missile thingy that does something similar.

Bdac addons, though, I dont know.