Shipwreck

Did I say that the relationship was linear ? Nope. Did I say that ROF was the only parameter that mattered ? Nope.

What I am saying is that ROF is one of the key parameters that governs MRSI capability.

__________________
"Blessed are the peacemakers, for they shall be called children of God" (Matthew 5:9)

Gun Grape

MRSI the new buzzword for "Time on Target". Pardon me while I yawn.

A good crew with a stopwatch, the Def/Quads and time hacks for all the rounds can shoot a 4 to 6 round ToT/MRSI. S-2 can compute the data using Cold Stick data with a TFT. I'll even set up the dart board and pull the fan out for him. It ain't friggin rocket science. But they are fun as hell to shoot.

As much fun as shooting the illum and shooting the HE under it with the rest of the btry.

(Gun Grape wonders off mumbling: Damn new breed of redlegs, back in my day we had real artillerymen, had to hump 8in rds 200meters to the gunline uphill
we knew how to shoot back then grumble grumble......)

S-2

"MRSI the new buzzword for "Time on Target"."

It's a one-gun ToT now. We called them Hi/Lo's. I dunno. Need a good A.G. at the elevation hand-wheel and that's about it. Four rounds easy on an 105mm w/ data figured and charges pre-cut (absolute safety violation IAW AR 385-63).

G.G., if you could get off six on a 155mm I'd easily believe it.

__________________
"This aggression will not stand, man!" Jeff Lebowski

S-2

"...to the gunline"

It was a feeling of family. Everything in it's place. Six weapons under nets. A safety and lay circle visible to the battery front. Collimators left front and aiming posts to the right rear.

Track extension out and chart table set up. 3kw humming and Freddy FADAC ready to shoot that first registration (M-90 chronographs fritzing again).

All was as it should be in artillery heaven.

Shipwreck

Assuming a tube elevation rate of 15 mils/sec, a maximum tube elevation for projectile loading of 600 mils and a 10-sec cycle time, the M198 could produce a 3-round MRSI (impact tolerance = 2 seconds) in the 14-23 km range band using a mix of M107 and M549A1.

Gun Grape

Damn Old Man. Where did the time go?

Gun Grape

Sit back and let the old guy tell you how its done.

those that wish to reference various 6-50, -10s,AR 385-63, or Regt/base/Marine corp safety SOPs need not respond

Max loading ele is 1000Mils. Projo cradled in left arm of ammo man. He kneels down and pushes round into powder chamber until rotating band engages swiss groove. and gets out of the way

You use 1 long and 1 short ramming staff section. Guy with biggest guns rams her home.

As soon as the staffs leave the breach powder man inserts powder in chamber, hitting swiss groove.

#1man closes breach. Takes primer out of mouth inserts into firing lock.
and stands to left side of breach.

(by this time ammo man has next round in hand and standing by #1 man and lt trunion)

Gets nod/ command fire from CoS. Pulls firing mech with index finger rt hand
As tube recoils to the rear brings right arm up, slaps breech locking mech with palm of right hand. Gravity opens breech. (And if you do it right, flames shoot out the tube. Thats how you get caught at night )

The dance starts all over again. Only exception is that the command to fire is "Quad XXXX Set". given by A-gunner.

Or at least thats how I heard it was done.

S-2

Gotta announce charge as it changes in the fire command. Nice if bubbles are actually level when the A.G. announces "Quad XXXX Set".

Gun Grape

yea, but you know this is a preplanned mission. A good FDC will have made up
cheat sheets for the section chiefs. Or a 4513 with all the info to give the chiefs. A good chief will have everything precut and laid out in the order of firing.

You announce "Fire tgt AB1001 charge 5, quad 1001" We'll take care of the rest

And you know, although I left it out that the section chief is checking the a-gunner with a gunners quadrant, sight pic/bubbles/reading on pantel, shell fuze and witness marks prior to anyone pulls the string to make gun go boom.

But just so you don't think I was totally reckless. On a mission like that, the A-chief acts as gunner, because you can depend on him. And the section chief plants his self inside the trails so he can observe the important things. Proper shell/fuze/powder charge going in the breach, Tube is within left and right limit marks. And does check quad with the gunners quad.

I was fast. Not stupid

S-2

Sam,

I've little doubt that you were probably one of the finest section chiefs that I'd ever lay my eyes on.

Yeah, I agree. It's a pre-planned mission. Initial and subsequent data is all computed and could be passed/copied from the ROF (DA 4504) to the ROMF of each gun section. Gun chief takes it from there.

Actually, thinking about it as I've never shot a battery hi-lo, once the initial fire command was issued, I'd probably shut down the land-line to the guns to eliminate any confusion and throw it in the gun chiefs hands.

Then I'd walk down to the gun-line and watch the show.

Shipwreck

All other things unchanged (tube elevation rate of 15 mils/sec., cycle time of 10 sec., impact tolerance of 2 sec., M107 / M549A1 mix), this increases the MRSI capability to 4 rounds (instead of 3) at ranges equal to 17 km, 18 km, 22 km and 23 km.

MRSI capability for all other ranges in the band (i.e. 14 km, 15 km, 16 km, 19 km, 20 km, 21 km) remains unchanged @ 3 rounds.

Gun Grape

Where are you getting the 2 sec tolerance?

All MRSI standards that I have seen were between 4 to 15 sec between rounds. Depends on the country. There is no "Hard" standard that I know of.

BAE has been testing NLOS-C to a 4 sec between round standard. Which I am assuming is the US Army set goal.

Do you have info that that has changed?

And you can play with the quad/charge combo to give more time

Shipwreck

For instance, this technical report (where I got the ToT figures I quoted earlier from) :

"Single Gun, Multiple Round, Time-on-Target Capability for Advanced Towed Artillery Cannon" by Timothy M. Kogler, Army Research Laboratory, Aberdeen Proving Ground, March 1995 (ref. ARL-MR-225) :

Indeed.

For the defunct Crusader, ORD requirement for MRSI (O-3) was 4-8 rounds within 4 seconds at ranges comprised between 5 and 30 km.

For the defunct ERGM, desired MRSI capability was 8 rounds within 3 seconds at a range of 40 NM.

For the defunct South African G6-52L (non-JBMOU compliant, 25-liter chamber variant), advertised MRSI capability was 5 rounds within 10 seconds at a range of 25 km.

Gun Grape

I believe that proved to be a unrealistic standard. Especially since they want all the new toys to have autoloaders.

As I said BAE is currently testing to a 4 sec standard.

I think this was one of those "Liquid propellant/automated fire? never obtainable goals for Crusader.

edit,

The 15 sec was one that France used in the late 90s to declare that they had a MRSI capable howitzer after the Germans started using MRSI as a selling point for their PZH2000s.

Gun Grape

OK now that we have hijacked the crap out of this thread I want to post something about the actual thread title

Followed Firrals link. One of the things that I like like least about this system is that both guns share the hydraulic recoil system.

Of all the systems that they chose to share, and its the only one, this is the worse choice you could make.

Howitzers normally go out of action because of recoil problems. And thats the system they share.

I see that both barrels have recuperators. So why share the system Unless the top ones are the recoil cylinders and the bottom ones the counter recoil cylinders. But I don't think so because of what looks like a cylinder between the barrels.

Give each barrel its own isolated recoil system. You can get rid of the muzzle brake. Or at least make it smaller. And squeeze out a fey extra meters of range. Plus having a more reliable system. And possibly a higher rate of fire.

Not that RoF isn't overblown when judging howitzer capabilities. Except for a MRSI mission with an autoloader, Rof doesn't apply to artillery like it does for small arms.

If anyone believes that the actual Rate of Fire for the M-198 howitzer is 4RPM for 2 min then 1 RPM sustained, or that the M101 could only fire 10RPM you are highly mistaken. And it doesn't take a highly trained crew to shoot higher RoF.