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FCUS 10/26/2008 4:00:17 PM

ArtyEngineer?

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ArtyEngineer FCUS 10/26/2008 4:29:27 PM

Ill reply in a bit mate, that horrible thing called work getting in the way at the minute though!!!

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neutralizer 10/29/2008 6:07:55 AM

About the only things they have in common is that they was both on wheeled vehicles and both 155mm, and being modern have electronic sights.

Caesar has a 52 cal barrel that conforms to the JBMOU. Archer does not conform.

Caesar fires bagged or modular charges, and is operated by a detachment in the open behind the gun, this lilits their rate of fire to normal modern rates (ie 3 rds in 15 secs, 6 or so rds per min for 3 mins or thereabouts, 2 rds per min for 30-60 mins perhaps more - basically it becomes a thermal management issue (which really only affects the top charge). The vehicle is reasonably compact but generally unarmoured (although like any wheeled vehicle there's no obvious reason why armour cannot be added to much of the cab) and seems to have a fairly limited top traverse (probably about 30 degrees, which is normal for a split trail towed gun).

Archer is a big vehicle with armour but is operated by a 3 man detachment in the cab. The 'turret', which has quite wide traverse is unmanned. This means that all ammo handling is automated, but the 'turret' can only hold some 20 rounds and takes some 7 minutes to reload (if mechanical handling equipment is available), manual reloading takes longer. This means that Archer is incapable of sustained continuous fire (or even several bursts of 5 - 15 rds with 2 or 3 mins between each which is fairly normal on operations). However, it can fire 8 - 9 rds per min (but not for long!). This also means that where there is a choice of shells there is an additional management problem (or a somewhat 'leisurely' response to calls for fire). It also appears that the propellant is cased and the charges cannot be varied (at least once they are in the turret).

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doggtag 10/29/2008 6:55:29 AM

Archer is a big vehicle with armour but is operated by a 3 man detachment in the cab. The 'turret', which has quite wide traverse is unmanned. This means that all ammo handling is automated, but the 'turret' can only hold some 20 rounds and takes some 7 minutes to reload (if mechanical handling equipment is available), manual reloading takes longer. This means that Archer is incapable of sustained continuous fire (or even several bursts of 5 - 15 rds with 2 or 3 mins between each which is fairly normal on operations). However, it can fire 8 - 9 rds per min (but not for long!). This also means that where there is a choice of shells there is an additional management problem (or a somewhat 'leisurely' response to calls for fire). It also appears that the propellant is cased and the charges cannot be varied (at least once they are in the turret).

I agree with you pretty much on everything but that last sentence.

(and I'm just wining it here, so bare with me...)

There's some good Archer linkage over here...

{ ht*p://www.fmv.se/WmTemplates/Page.aspx?id=1378 }

"Magazine
Shell magazine, capacity: 21 projectiles
Comment: The magazine handles all 155 mm projectiles with a length of maximum 1000 mm and a weight of maximum 50 kg. The grenades are arranged in ready-use rounds in numbered bowls. Manually settable fuses are set in advance while inductive settable fuses are automatically set in the ram phase, immediately prior to firing. The gun computer monitors all ammunition data and when firing is ordered, the desired bowl is commanded to the feed position automatically.

Charge magazine, capacity: 18 rounds
Comment: The magazine handles both bag charges and modular charges. The ready-use rounds arranged in numbered bowls. The gun computer monitors all ammunition data and when firing is ordered, the desired charge bowl is commanded to the feed position automatically. At present, the size of the charge for each respective charge bowl is determined when filling the magazine. One potential area for development is a different type of charge bowl that only handles modular charges but with the advantage that the charge size is not predetermined but can be adjusted to the combat circumstances. "

Now I don't know that I read that as it can carry 21 rounds but only enough propellant charges for firing 18 of them (which would seem totally pointless...why even bother carrying rounds of ammunition you can't actually use?),

but rather each of those 18 rounds of charges is probably made of of several increments (bowls as they call them), I'm guessing a few/several for each "round",

so that way, you might fire 6 or 7 rounds with the maximum number of charge increments each (perhaps this is where they refer to it as a full "round"),

but for several other shots you might only need 1 or 2 charge increments...

(for example, go here... and select their Gun Propulsion link, to see Denel's M90 Bi-Modular Charge System,...I'm going to go out on a limb and suggest that when the Archer says "18 rounds of charges", they may well mean a full stack of those increments (6 pieces), which can be selected separately or all at once...

{ ht*p://www.dlswc.co.za/ })

...or maybe you are on the right track, and I'm just reading/interpreting too far into it (on the Archer).

I'm sure AE will be along shortly to either dispel or confirm this...

Other than having a much shorter barrel (38-cal in production),

I'm under the general impression that the autolader in the NLOS-C works on the same principle.

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FCUS thx 10/29/2008 12:38:03 PM

Thank you Neutralizer and Doggtag for your information and your time. Now I can see the main differences between the two.

Please correct me if im wrong but in a nutshell we have:

CAESAR => lighter vehicule and thus not very well protected but easily carriable by C130/A440/etc, reasonable rate of fire but slow compared to ARCHER, however capable of sustaining continiuous fire because there is no need to reload the turret, and there is no ammunition management problem. the main issue is thermal "management".

ARCHER => armored vehicule thus offering better protection to the crew, unmanned turret with a high rate of fire and a wide traverse (and so a better range?), however incapable of a continious fire because of the limited amount of rounds in the turret and the long time needed to reload it. There is also a ammunition management issue.

Now im looking forward to AE's answer^^

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ArtyEngineer FCUS 10/29/2008 5:09:23 PM

I apologise, Im itching to have the time to sit down and give my thoughts on both these systems. Ive actually been up close to both. Havent seen either fire unfortunately but have talked extensively to the Bofors Guys regardign Archer and know folks at Yuma Proving Ground who have been involved in some testing of the Caeser. Both systems have things I like and things I dont like. Will elaborate more I promise. These days I look at everything from a maintenance perspective!!!! The system which has the better performance characteristicvs may not be the one I would choose to go into combat with!!! Look for a detailed response Friday. Im in the middle of a Battalion Fielding right now but by Friday I should have a bit of time.

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doggtag a big thing I like about Archer.... 10/29/2008 5:44:41 PM

...after watching numerous videos (mostly snippets from Future Weapons)

is how they can use the CROWS-type turret ( called LEMUR ) sensors to slew the main gun for the direct fire role.

That was no small stroke of genius on their part...

The Future Weapons link I pulled from LiveLeak, over here... (for those of you guys who have issues watching YouTube clips).

{ ht*p://www.liveleak.com/view?i=226_1218554347 }

Or, if you prefer no snow, you can check out this video... instead...

{ ht*p://www.liveleak.com/view?i=94f_1199174617 }

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neutralizer 10/30/2008 4:37:03 AM

Wider traverse has no effect on range.

Caesar is a reasonably mature design and is or is about to enter service.

Archer seems to vary and still be evolving. The story as quoted doesn't entirely hang together. My understanding had been that Archer was based on FH77A type ammo. This was cased in accordance with Swedish practice. However, FH77B uses bagged charges. Bagged charges need seperate primers and magazines for these were introduced almost 40 years ago with FH70 (still the most innovative gun to enter service since 1945). Bagged charges in Archer has to be a bit of a joke, there's no way that the internal workings of the Archer turret can put together the right charge from bags, that means the gun can only fire with what it's got prepared. Whether or not there's some way of a quick manual fix with a guy hopping out of the cab and rushing around the back is another matter (never mind the scope for unchecked mistakes)! However, modular charges can be assembled at the breach, the French introduced this a few years with the upgrade to the AUF SP. I don't think they've bothered about it for Caesar.

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FCUS ArtyE 11/6/2008 11:01:14 AM

I hope your operations went well last week. Im checking this thread 2-3 times a days for your answer, that how much i'm looking forward to it.

Hope you'll find the time soon

FCUS

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ArtyEngineer For FCUS 11/8/2008 9:58:33 PM

Ok, after much delay here is my opinion of these two systems. I hope FCUS that you are not some Gov Procurement type waiting to make a decision based on what I say!!!!!

Both these systems are 155mm 52 cal howitzer systems mounted on a 6x6 Truck chassis. From that description someone may assume that they are very similar systems, they are NOT. It?s obvious that both were designed to meet different requirements for their respective militaries, specifically with regards to size/weight limitations and crew size amongst others.

The above pictures and sketch showing relative space claim should well illustrate the difference in sizes and configuration of these vehicles.

The Archer is based on a Volvo Articulated Hauler, while the Caeser is based on a Renault truck. From a tactical mobility point of view I would have to give the edge to the Archer. That Volvo is a ?Beast?, but from a Strategic mobility point of view it?s clearly in favor of the Caeser with its ability to be deployed via C130. Now the Archer is touted as being A400 M compatible, however let?s just wait until that Aircraft is actually in production and in service with someone before we use that as a reason to favor one system over another!!

From a maintenance point of view I would have to give the edge to the Volvo over the Renault purely due to the environment and abuse that vehicle was designed to withstand. Ill talk a little bit more about maintenance later.

From an Armament perspective it?s very important to note that the while both 155mm 52 cal tubes the Caeser is JBMOU compliant while the Archer is not. The Caeser has a Chamber volume of 23 liters, while the Archers is 25 liters.

What this means is that the Archer can fit a larger charge into its chamber. In fact a complete charge system was developed specifically for the Archer and its automated load system. This charge system is the Uniflex 2 modular charge. It has 7 increments one of which is a ½ increment giving 12 different charges which can be fired. See pictures below:

This range of charges is what gives the Archer a very useful MRSI (Multiple Round Simultaneous Impact) capability throughout a good chunk of its total engagement envelope. For quite some time I was unsure of the merits of the MRSI capabilities however I have came round to appreciating its value for guns operating in reduced numbers as is currently the case in Afghanistan and Iraq where 2 gun detachments are common spread around the Area of Operations (AO) in different Forward Operating Bases (FOB?s).

Where the non standard chamber volume lets the Archer down is in regards to what ammo it can fire. Due to the fact that the ballistic performance for this cannon is not standard, work has to be done on any ammo you wish to fire from it with regards to ?Firing Tables? development. This can be expensive. This fact alone I believe has hurt the Archer with regards to export potential. Also, when using the top charge many existing projectile and fuse combinations may not be able to withstand the loads.

Now the French have also developed a JBMOU compliant charge system with 2 different types of increments covering zones 1 to 6. This also gives the Caeser an MRSI capability however its not as wide as the Archers. I believe the Caeser however can also use non modular bag charge systems still currently widely in use around the world. For a Caeser user this creates a much easier logistics burden knowing you can fire coalition partners 155mm ammo systems with no issues. I asked a Bofors guy quite recently why they made the decision to not stick with a JBMOU compliant system. He looked at me with a very ?Pained? expression which I think indicated he was sick answering that question!!!! His response was ?Its called Progress?, which I can?t really argue with.

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