US Navy's rail gun

[DWReese]

Here is an article about a subject that I'm not very familiar with: the rail gun. I think that this article is pretty interesting. Hopefully, you will too.

https://www.yahoo.com/news/u-navy-wants ... 00289.html

Doug

[c3k]

Railgun tech is interesting...but the projectiles are, so far, just envisioned to be solid penetrators. Until they can solve the HE fill and fuzing issues (making a shell that can withstand launch and still function), then these penetrators will not bring much "bang" at the end of their flight. Their velocity will decrease as range increases, lowering their kinetic energy. Maximum range may mean minimum effectiveness. (There is a middle ground, where they may not lose much velocity as they go above most of the atmosphere. Think of the German WWI Paris Gun.) This may create a donut-shaped effectiveness pattern. Good up close, worse in the middle, improving at further distances. That all pre-supposes they cannot solve the construction issues with a filled shell.

Then, as your linked article states, the power requirements are quite high.

[ARCNA442]

ORIGINAL: c3k

Railgun tech is interesting...but the projectiles are, so far, just envisioned to be solid penetrators.

People keep repeating this, but it isn't actually true. For years the planned projectile for the railgun has been the GLGP (gun launched guided projectile, formerly HVP or hyper velocity projectile) - a guided shell with an HE payload. The kinetic energy option is a remnant of early railgun concepts and seems to have been driven by the idea of improving ship survivability be removing all explosives from the magazine.

[c3k]

ORIGINAL: ARCNA442

ORIGINAL: c3k

Railgun tech is interesting...but the projectiles are, so far, just envisioned to be solid penetrators.

People keep repeating this, but it isn't actually true. For years the planned projectile for the railgun has been the GLGP (gun launched guided projectile, formerly HVP or hyper velocity projectile) - a guided shell with an HE payload. The kinetic energy option is a remnant of early railgun concepts and seems to have been driven by the idea of improving ship survivability be removing all explosives from the magazine.

Obviously, news to me.

Off to dig into it. However, the stresses of accelerating to the velocities needed for the long-range will still be just as daunting.

Edited to add: I just found a link, https://www.janes.com/article/86130/us- ... er-options
This story explicitly states that the GLGP is meant for the Mk45 5 inch gun. Almost like a Navy version of the Army's 155mm Excalibur round. This is FAR from use in a railgun. However, another article states it could be used in both the 5" gun and a future railgun. This leaves me more confused.

[ARCNA442]

ORIGINAL: c3k

Edited to add: I just found a link, https://www.janes.com/article/86130/us- ... er-options
This story explicitly states that the GLGP is meant for the Mk45 5 inch gun. Almost like a Navy version of the Army's 155mm Excalibur round. This is FAR from use in a railgun. However, another article states it could be used in both the 5" gun and a future railgun. This leaves me more confused.

Here's the single best source of information: https://assets.documentcloud.org/docume ... Guided.pdf

Basically, the long range of the railgun necessitated a guided shell to actually hit anything. This became the HVP (hypervelocity projectile). The Navy then realized that since HVP was already a sabot round (the railgun's electromagnetism is applied to a square sabot rather than the shell itself), they could just reshape the sabot and fire the round out of their existing 5" guns as well and fill the void created by the cancellation of ERGM / BTERM / LRLAP. This then got spun off as a separate program from the railgun itself and was renamed the GLGP with immediate fielding from 5" guns as the main objective with adaption for the railgun down the road.

[c3k]

Thanks!

I found this: https://news.usni.org/2019/05/21/report ... rojectiles

It has an embedded document that describes, in good detail, all about the GLGP with various drawings and specifications.

Interesting...

[ARCNA442]

ORIGINAL: c3k

Thanks!

I found this: https://news.usni.org/2019/05/21/report ... rojectiles

It has an embedded document that describes, in good detail, all about the GLGP with various drawings and specifications.

Interesting...

Yep - that's the same document I linked [:D]