Martin Baker Long Ranger NF.1

rickshaw · February 18, 2018, 09:05:36 PM

Looks to me like whoever wrote the Spitfire book used the diameter of the driving band, rather than the diameter of the shell, itself. Driving bands are compressed into the lands of the barrel (the rifling) to make a gas-tight seal. They are usually a bit larger in diameter than the shell. They are usually made of a softer metal - copper/brass, iron (something the Germans like to use a lot of). Artillery uses the shell diameter to determine calibre of a gun/howitzer, hence the differences between 7.2in and 7.5in.

kitnut617 · February 19, 2018, 07:49:26 AM

Yes, but it helps if I read the book properly too ----- it does say 7.2"

why I read 7.5" I've no idea

kitnut617 · February 19, 2018, 07:53:46 AM

So, here's Triplex Rocket.1 to Guy's measurements for the shell. It's actually just a tad over scale but close enough for me. The length is correct, just the diameters of the motors and shell that are slightly over scale.

It now looks much closer to what appears in the book.

I'm going to go with two of these (one under each wing) and a pair of 2" folding fin rocket pods with four rounds in them. If what a Wiki article says is correct, pods were developed very soon after WWII ended, so as this is Allied '46, pods were developed earlier (or I should say during the war)

NARSES2 · February 20, 2018, 06:18:38 AM

Nice work on the rocket mate

Old Wombat · February 20, 2018, 06:31:25 AM

Good work!

kitnut617 · February 20, 2018, 07:52:14 AM

Thanks Chris, Guy.

I've now got two made so it's on with another round of PSR for minor kit fit problems (which I hope will be the last one).

dwomby · February 22, 2018, 06:35:48 AM

Wow - I just found this. Great work.

David

kitnut617 · February 22, 2018, 05:32:20 PM

Thanks David

Weaver · February 22, 2018, 05:44:42 PM

That's a good-looking piece of work - nice one.

Found these pics of the rocket online here: https://forum.worldofwarships.eu/topic/79521-missiles-on-carriers/?page=2

kitnut617 · February 22, 2018, 06:09:46 PM

Thanks H, and a fantastic find with those photos. They answer a question I had about whether the three motors fired through one opening, now I know they didn't. And it looks like I have got to move my fins, adding more straps is a bit late so I'll leave those I've done as is.

Looking at the fin orientation, it would appear that the Triplex could be mounted on regular RP-3 zero-length launch pylon positions.

And I've had a change of plan --- again. Not going with the four-shot rocket pods, I'm going to use some of those 2" RP sets of three stacked rockets, the ones found in the old Airfix Hunter kit. So Triplex inboard, two stacks of three 2" RP's outboard on each wing. Should give it some clout --- right ---

Weaver · February 22, 2018, 06:46:11 PM

Glad they were useful. The triplex rocket reminds me of an idea I had for a UK equivalent of Genie that would use three Firestreak bodies for the motors.

There was another project for an anti-ship rocket called Uncle Tom that used six 3" motors. It led on to the Red Angel anti-ship weapon under development in the late 1950s, however I don't think either entered service.

rickshaw · February 22, 2018, 08:21:51 PM

Quote from: Weaver on February 22, 2018, 06:46:11 PM
Glad they were useful. The triplex rocket reminds me of an idea I had for a UK equivalent of Genie that would use three Firestreak bodies for the motors.

There was another project for an anti-ship rocket called Uncle Tom that used six 3" motors. It led on to the Red Angel anti-ship weapon under development in the late 1950s, however I don't think either entered service.

Are there any pictures of the Red Angel?

zenrat · February 23, 2018, 12:57:46 AM

So how many rockets could you fit behind a 16" shell? 19?
Would it fly?

kitnut617 · February 23, 2018, 02:44:18 AM

From what I've read, the RP-3 motor was a very simple motor, a length of 3" nominal pipe stuffed with cordite. Looking at the photo of the rear end, it looks like sch 20 pipe too.

They used three PR-3 motors for the Triplex because mainly it was in mass production and they didn't have to design or test a bigger motor. And it did the job ---

There's another photo I have in a book somewhere of two Triplex rockets mounted under the fuselage of a Mosquito, got to find where that is now ----

rickshaw · February 23, 2018, 03:25:39 AM

It was actually a little more complex than that. The cordite in the motor was shaped into a cross, with a cavity running down the middle. This caused some well, "interesting" effects with the rocket's burning unevenly and some serious research had to be done to cure it. Apparently shockwaves built up inside the motor and cause the cordite to burn unevenly, which resulted in variable velocities. I remember reading an article about it somewhere or other. It was quite interesting how the research carried on after the end of the war to try and cure the problem. In the end, they simply redid the cordite into a triangular shaped cavity, where the shockwaves bounced down the tube, more evenly.