2017/08/03

Split trail howitzer carriages and hyped weapons in general

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I have pointed out that split trail howitzer carriages have a responsiveness problem beyond their (no more than 62°) traverse. They lack the unlimited 360° traverse because of their carriage. The split trail carriage was a huge improvement over the box trail when introduced in the Déport gun, but it's no good if you need to respond to a call for fires outside of the ~60° traverse. A well-drilled team takes about two minutes to lift up an otherwise well-designed split trail carriage tail and turn it around for a fire mission beyond the previous traverse. For comparison; a self-propelled howitzer with a 360° traverse turret may execute a 3 round fire mission on the target and redeploy by hundreds of metres in those two minutes.
There have been platforms used (in times long gone) to give box trail carriage guns a 360° traverse, for example the Arbel platform. The British 25 pdr gun of WW2 fame was such an example. This solution isn't a good one either. The platform adds a lot of weight, slows down deployment and redeployment and mobile platforms of this kind do not transfer the recoil force into the ground. That's still being done by the tail of the carriage, typically some spade.

And this is one more problem if you need to turn around your gun like that. Look at 1:25 of this video:


You can see how the spades are not fully embedded in the soft soil until after the first shot. Thus either you have to accept several seconds additional delay between 1st and 2nd shot (which ruins the surprise effect on the target and makes HE fires much less effective) or you have to shoot a charge without a shell arriving at the target, only to produce enough recoil force to set the gun. This adds additional seconds to the two minutes mentioned above.

Let me explain why this is so important; I wrote in several of my articles on infantry tactics and survivability that infantry should move or even break contact within 2 (at most 4) minutes of being detected by opposing forces. The reason is that opposing forces' indirect fires may arrive after such a short delay. Very competent readio-networked artillery with SPGs, electronic fire coordination, not too far away, minimal if any deconfliction requirements and can deliver a devastating multiple round multiple firing position simultaneous (within seconds) impact fire mission that quickly. The state of the art squeezes infantry into such tight limits; two, at most four minutes to pull off what they ought to do, then move or die. Poor quality armies may take 10 or 15 minutes to do the same, but one shouldn't orient yourself against such opposition; they won't dare to attack NATO anyway.
Now imagine our arty has an additional, unnecessary delay of two minutes on many fire missions. This may easily halve the quantity of elusive infantry platoons that they can catch. It wouldn't matter against cumbersome and poorly led infantry, but again, arty officers who intend to prepare against those only would have pursued the wrong career.

It needs be mentioned that split trail guns also take painfully much time to redeploy compared to self-propelled guns, making them much less suitable for shoot & scoot high survivability drills (= unsuitable, sitting duck targets).

Few modern armies still use many such towed, split trail carriage howitzers. They're mostly in use as helicopter-portable light guns for airborne forces, as artillery ordnance for reserve forces or in the U.S.Army. The U.S. Army failed to develop or accept a proper and already developed self-propelled gun for its 'medium' ("Stryker") brigades, and is still stuck with these towed howitzers. They even want to increase the range of the M777 (which has the barrel length and range of 1970's howitzers of its calibre), that's how much they're invested in the M777's basic design.

WW2-style howitzer with split trail (and a gunshield)
German WW2 experiences led to requirements for howitzers
with 360° traverse and about 70° maximum elevation.
Only the increase of maximum elevation became a
dominant design choice post-WW2 save for the
Soviet 122 mm D-30 and a Swedish howitzer.
I consider this an example of how hyping and overhyping weapon systems and military procurement programs can badly hurt an armed service. The M777 was hyped for years because it was new, it was American, and it was made with expensive alloys to cut down weight (supposedly to allow UH-60 helicopters to lift it, which is hardly ever done). It did not deserve any praise. The weight reduction served no real purpose to its current users but inflated costs. The dispersion is not extraordinary good compared to other modern howitzers, the attached muzzle velocity radar is nothing extraordinary for new arty guns either and the range is stuck in the 1970's. Still, there was about a decade of hype for this gun.

This hype has blinded the public; hardly ever do I read any harsh criticism of the obsolete towed split trail approach. Sure, the Taliban and other "light infantry, motorcycle & technicals" opposing forces were not able to overmatch the M777, but they would have failed to overmatch a WW2 howitzer as well. A modern conventional land power ('peer enemy') such as the Russian army could do so easily, especially in mobile warfare. They don't even need to be able to operate counter-artillery radars; old school flash spotting and sound ranging still work and they even develop new devices for it, and the M777's relatively poor range makes it more susceptile to this than the longer-ranged 52cal 155 mm SPGs are.



The organic artillery of the light and medium brigade combat teams of the U.S.Army and of the USMC is poor, and the hype blinded the nation to it so the weakness lasts. Higher level support artillery (MLRS) doesn't compensate for this; the U.S. did not sign the cluster munitions ban, but it's still getting rid of its ICM/DPICM munitions. There are no unguided HE rockets for MLRS.


A nation should avoid hyping military hardware, period. It serves no other purpose than entertainment, and that should NEVER be a purpose of the military. Hyping military hardware risks to cover up its weaknesses and thus inhibits actions that would mitigate or eliminate such weaknesses. This appears to be true regardless of insider experts understanding the true deficits.

S O
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15 comments:

  1. Better get ordering the PzH 2000 then... ;)

    Seriously though for light and medium formations what does work?

    105mm towed howitzers a la 'light gun' and CAESAR type systems?

    I seem to recall you posting a link to 105mm howitzer self propelled on a humvee, would something like this still be your preference?

    And does a medium weight 360° traverse 155mm option exist, you mention a Stryker option, was this ever tested or used in other contexts? What would you recommend?

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  2. Wikipedia says Slovakia have an 8×8 155mm SPH with 360° traverse in service. ZUZANA 2. Looks pretty handy.

    https://en.m.wikipedia.org/wiki/155mm_SpGH_ZUZANA

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  3. I understand if the Americans don't want to use 105 mm calibre due to standardisation. The M 777 still makes sense at most for India (at its Himalaya border with the PRC), so the Americans should simply replace almost all their M777 and sell them to India.

    ZUZANA has a 45cal barrel with inferior range compared 52cal SPGs.

    A 360° 155 mm 52cal SPG would be the best option. AGM and Archer come to mind.
    http://www.military-today.com/artillery/archer.htm
    They - particularly AGM - could even replace both M777 and M109 once the weapon system is paired with American fire control & radio tech and an American chassis. PzH2000 would be better for the heavy BCTs due to munitions capacity and resupply speed, though.

    A towed gun is necessary for heliborne or airborne employment; the Americans would certainly stick to M777 (sunk costs, ammunition in depots) rather than to buy a 105 mm gun, but no more than a few dozen would be needed for all airborne/heliborne forces of the U.S..

    (Archer was developed for Norway and Sweden. The U.S.Army could have completed not much more than concept and feasibility studies with that kind of development budget.)

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  4. Archer doesn't do 360. And both Archer and AGM is grounded in a belief that technology is the solution to everything.
    Neither of these can do prolonged fire missions because the magazines can not be topped upp during fire missions. Maybe not that important for a country like USA but, if you intend to bring in something to replace Paladin it should not loose a capacity.

    IMO you either go along the lines of K9 or if absolutely necessary, PzH2000.
    Or you go along the lines of the original Caesar/Atmos2000 for lower cost and less need for HET trailers(although that is a lie in reality, most users place these trucks on HETs anyhow...).

    Towed is OK for units that fight positional war like USMC, only doable under a ridiculously large air umbrella.

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    1. Right, I looked up Archer and it does 170°, not 360°.
      http://www.baesystems.com/en/download-en/20170725165426/1434555671252.pdf
      30 seconds into and 30 seconds out of position equals up to one minute for repositioning, still only half as much as M777 needs for pivoting (if there's enough room to manoeuvre a large lorry at all).
      That's both hugely better than the poor 46° of M777, which are one of the if not the worst traverse characteristics among split trail carriages. The Déport gun of pre-WWI already had 54°. Archer doesn't fit into a C-130, but I doubt that this could matter much.

      Prolonged fire missions and shoot & scoot don't fit together unless you think of units, not individual guns. I suppose prolonged fire missions have no place in high end conventional warfare until the opoposing force is badly degraded already. I think prolonged fire missions in NATO defence are good at most for reduction of pockets.

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    2. Why is 360 necessary? Is 170 not fully sufficient?

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  5. And a last note Archer was designed an built for Sweden.

    Norway's stupid mess into that system was some political bullshit.
    The system just didn't fit into any part of the Norwegian defense doctrine or in the terrain.

    If it is really fit for purposes for the Swedes, is another question.

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  6. What about Polish (mostly South Korean in fact) Krab? - Denel`s G7/LEO should be good enough for American paratroopers/Stryker brigades, but... - By the way, Slovak Zuzana in its first version (ZUZANA 2 has 52 calliber barrel) represents a little bit inferior design, but Czechs will buy even worse "modernized" SPGs from seventies in old 152 mm WP caliber with effective firing range 25 500 m. - Europe really needs common military aquisition agency, because too many countries use technically inferior/too expensive/inferior and still too expensive "patriotic" systems.

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    1. There's little difference between Krab and PzH2000 in the specs that I saw unless your bridging is for MLC50.

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  7. Prolonged fire missions and shoot & scoot don't fit together unless you think of units, not individual guns. I suppose prolonged fire missions have no place in high end conventional warfare until the opoposing force is badly degraded already. I think prolonged fire missions in NATO defence are good at most for reduction of pockets.


    My point was that it would be quite stupid to spend millions on a weapon system that is les capable in certain ways than its predecessor.

    If a combined arms group need to cross some open terrain before they could start demolish an enemy position themselves. more shells could be needed from a battery than the 60 on each gun.

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    1. A wheeled SPG like Archer would be a replacement for M777, no downgrade at all. Even if it was used to replace M109 as well, it would have both improvements (range, rate of fire, road marches) and reductions of capability (munitions, munition supply, traverse).

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  8. Can the firm that developped the 105mm soft recoil Hawkeye not develop a 155mm version on a simple tracked base e.g. from a light tank? Only asking.

    Conclusius

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  9. Hi Sven- Not my place to correct you; but I believe the M777 is a British design and is built by BAE with significant parts built in the States. The guys over at ThinkDefence did a piece a while back about it going over some of the traverse issues you mention.
    http://www.thinkdefence.co.uk/2014/07/105mm-155mm-something/
    The Indians bought it in part because it dovetails with the Mountain Strike Corps needs and also because their new Chinook acquisition can carry it.

    --Dev

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  10. M777 has insane range with excalibur and that is how it's most likely going to used against a "peer enemy".

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    1. Everything has a an improved range with the later versions of Excalibur, with Vulcano et cetera. And I've read that Excalibur range excuse for the M777 often enough. It's bollocks. Excalibur is unsuitable for most artillery fire missions and available in small quantities only. There are less than 7,000 rounds. A brigade's artillery could be expected to expend 8,000 rounds in a day.
      Also, "peer enemy" and GPS navigation don't match. The "peer enemy" would be expected to jam the weak GPS signal, possibly even with satellites.

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