Self-propelled Artilllery Questions

1. What were the most effective models (hummell, wespe, priest, etc.?)

2. How decisive are these weapons? Conventional artillery took around half an hour to set up but were far more numerous.

 

This is inherently an opinionated response.

I'd say the Hummel and Marder were the two best in retrospect. One allowed heavy artillery batteries to move quickly around the battlefield (particularly with the shift of initiative, most importantly the increasingly transient nature of air superiority) including fire and relocate doctrines. These were devastating around Stalingrad through October '42, Mamayev Khurgan became a graveyard legend for the second time in its history.

The other was a fantastic use of relatively limited resources. Keeping the PzII chassis in production with a 7.5cm or 76.2mm PaK mounted was simply brilliant in practise, it was a tremendousy effective tank killer at low cost, which more than offset its high defensive profile and simple construction.

The Wespe also, applies the 10.5cm howitzer to the PzII chassis and is a similar theme, great use of existing production for a weapon which was tremendously effective in the field. You can't beat this for mobile fire support and it reputedly increased the effectiveness of panzergrenadier battalions manyfold.

In straight up head to head comparisons though, the Hetzer is king. Cost and mobility versus firepower and protection and it tosses in great concealment, it can't be beat by anything as a tank killer.

 

In the medium category, the M7A1 Priest hands down. The German models were mostly hasty lash ups that were not well thought out. The Wespe limited the elevation of the gun and the chassis was really a bit overloaded. The M7A1 mounted the 105 a bit higher in the vehicle over the original model giving it equal range to the towed version. The M7 also carried a good number of rounds on vehicle, something the German models seemed to never quite get right.
In the heavy gun category the Hummel is likely the best vehicle. It is much better than the US M12 that was another hasty lash up. The M12 lacked range due to poor elevation. I've seen photos of M12 units using ramps to increase the firing range.
For lighter pieces the M8 MGC is likely the best design. This is a compact vehicle with a 75mm howitzer in a fully rotating turret. It is fast and reliable.
The British really never got a really good SP artillery piece into service and had to rely on re-gunned M7s instead. The Soviets also made a number of decent SP artillery pieces (SU 76, 122 or ISU 152) but their lack of a good fire control system made them deploy theirs more as assault guns than true artillery.

SP artillery has two huge advantages over towed. First, it can get into and out of firing position far faster than a towed gun. Its mobility also allows it to be were it is needed easier than towing. Second, in a pinch SP artillery is fairly effective at defending itself. Far moreso than towed guns are. This doesn't mean towed artillery is helpless or defenseless just that it is harder to get towed guns out of situations where they are being assaulted.
Both types still are largely dependent for effectiveness on the system they are integrated into. The US obviously had the best artillery control system followed very closely by the British. The German system tended to be too decentralized and lacked the communications flexibility the US and British had.

 

On this particular comment I'd say you are wrong. The Hetzer was really little more than a death trap for its crew. The chassis is just teetering on being overloaded. The design puts three crew in a row (driver, gunner, loader) on the left. The commander is seperated from the rest of the crew on the right side by the gun.
There are only two crew hatches on the vehicle and both are small. In an emergancy the loader, gunner and, driver must all exit through the loader's hatch. This, of course, assumes that the remote control machinegun is not blocking it.
The commander has his own hatch on his side of the vehicle.
The gun has the worst traverse of any German tank destroyer: 11 degrees right, 3 degrees left. The ammunition is stored on the right in front of the commander. To load the gun the loader must reach over or under the gun and pull rounds out of the ammo racks. This requires something of the ability of an Olympic gymnast in many circumstances.
The visibility from the vehicle is downright terrible. The driver has just two small vision slits for a view. He is totally dependent on the vehicle commander for direction. It is also possible for him to not notice the vehicle creeping forward while in low gear.
The gunner has just his periscopic gunsight for view. The loader has a single periscope on the side of the vehicle. In addition, he is also responsible for operating the remote MG on the roof. This is normally equipped with a 50 round snail drum magazine. To reload the gun the loader must expose himself outside the vehicle and reach over the shield that protects the gun from return fire to reload it.
The commander has a periscopic set of artillery bionoculars along with two periscopes to view the situation with. But, he is sighted so far back on the vehicle that the roof blocks much of his view of the terrain close to the vehicle itself.
The armor in front is decent but elsewhere it is paper thin. It is interesting to note that the Waffenamt covering AFV though lowly enough of it to redesign the Hetzer in its 1945 model (never produced) into a vehicle more like an improved Marder with an open top.

But, don't take my word for it. Even the actual crew wasn't impressed.

http://www.pzfahrer.net/

 

Kind of similar to this thread and there will probably be the same responses LOL.

http://www.ww2f.com/weapons-wwii/23556-favorite-assault-gun-self-propelled-gun.html

 

I remember you discussing the Hetzer before T.A. .

http://www.ww2f.com/weapons-wwii/12494-hetzer-v-stug.html

 

I'm a proponent of mobility and firepower and go with the Hummel, heavy gun on a proven chassis.

The ability to keep the artillery forward with the advance meant being able to capitalize on break throughs at the front. This in turn would allow the artillery to deepen int's range into enemy territory and have the added benefit of being able to shoot and scoot thus avoiding counter battery fire reletive to towed pieces.

In short no mechanized force should be without them. It's more tacticly flexible and allows the momentum of the offensive to continue without having to wait for the artillery to catch up.

My 2 cent's

 

No actually the statements I made were indeed my opinion. But thanks for thinking you were me.

 

The M12 and M40 GMCs. My 3 cents.

 

A bit more on question two:

If we start by assuming that the probability of firing on a target (P) is a function of the the range of the gun (R) divided into the area the target could occupy (A) we get a rough baseline of this probability.
In turn, 1- P is the probability that the battery will have to move to engage the target.
Next, the time to move the battery is simply a function of adding the time to limber up / prepare to move, plus the time to move or movement rate, plus the time to unlimber and set up the battery when it arrives. Let's call this Tm.
The overall distance to be moved by a certain time (Dm) is divided by Tm giving the time to displace to the new location for fire (N).

Combining the two gives us the probability of successfully (Ps) displacing to the new location and engaging the target:

(1-C/A)(Dm/Tm) = Ps

Example: We have three 105mm batteries with four guns each capable of firing 6 miles. One is self propelled, one is motor drawn, and one is horse drawn. The engagement area is 10 miles in diameter. The move distance is 5 miles and the time to displace is:

Self propelled 1 hour (15 minutes to ready, 15 minutes to move, 30 minutes to emplace)
Motor drawn 1.75 hours (30 minutes to limber, 15 minutes to move, an hour to emplace)
Horse drawn 2.5 hours (1 1/2 hours to limber, 1 hour to move, 1 hour to emplace)

The Ps for each then is:

Horsedrawn (.92)(16/2.5) = 5.888
Motorized (.92)(16/1.75) = 8.411
Self Propelled (.92)(16/1) = 14.72

If we then say that the battery has a firepower of 4 (1 for each gun) and score these (rounded) using the above probabilities we get a potential firepower of

Horsedrawn = 4
Motorized = 6
Self Propelled = 10

While all of this is a bit arbitrary and I'm really cutting down the example to a bare minimum, what it shows is that better mobility is a real force multiplier. In our example having a self propelled battery essentially more than doubles the potential firepower of the battery simply because it can be in the right place at the right time more often than a tractor or horse drawn battery can.
That is why everyone went to self propelled guns for artillery if they could.

 

Outstanding and informative posts on the subject, TA.

 

I've actually never heard of these weapons and don't know how widepread there were in US forces. I thought the Priest was overwhelmingly used.

 

Wolfy, see here: M12 GMC and M40 GMC

Th M7 was the standard equipment for the Armoured Divison artillery regiment, although there were large numbers of M7 equipped non-divional artillery battalions at Corps reserve, to be assigned as required. These larger calibre guns were also independent, and employed likewise.

 

I spent the better part of my career in the artillery. The first two years were primarily with the M101, which was the redesignated M2 105mm hositzer of WWII. We also had the M114 155mm Towed, M109 155mm SP & M110 203mm SP, in the regiments which I also trained with. The prime mover for the M101 was the 2.5 ton truck the same as WWII.

I also have the Combat Readiness Standards book on my desk here.

Time allowed for readying a battery to fire is:

Daylight
M109, M101 8 minutes
M114 15 minutes
M110 9 minutes

Night
M109, M101 16 minutes
M114 22 minutes
M110 18 minutes


This from the time the first howitzer enters the firing position until the last is confirmed as laid on the Aim Point or the Aiming Stakes & ready to fire. We assumed a six howitzer battery vs the four of the WWII US battery. It was expected the Fire Direction team would be ready to compute data within that time.

In the mid 1980s we replaced all the above cannon with the M198 155 towed Howizer. The emplacement time for a six cannon battery of these eight ton monsters was 10 minutes daytime & 20 @ night.

These were maximum times allowed and were realatively liesurely for trained crews. On a average day 30% could be knocked off the time. The largest difference at night was in the inability to lead the vehicals into the poistion at a run, the section chief or guide had to move at a walk so as not to fall in front of it in the dark.

Displacement times from a position for the howitzers was similar, tho ordinary departures were not scored. Emergency displacements, where the non essenitial equipment is abandoned for later recovery required the last howitzer leaves the position within three minutes of the order. "leaving the position" is defeined as being 200 meters from the cannon or vehical starting point. This was possible with the M101 or the SP. The 155mm towed M114 or M198 required more time to raise the pedistal and relimber on their road wheels. Some some reason the evaluation book was not altered to reflect this & the evaluation team had to fudge the stopwatch.

In the section concerning subsequent tasks it was required the auxillary elements of the battery be in their assigned positions within thirty minutes of the intial occupation.

 

Interesting. They seem to be very rare weapons compared to the Priest. Fewer in number than the Hummel.

 

Why are there two types of self-propelled artillery and what types of differing situations are they used?

The 105mm and the 150-150mm class?

 

Projectile weight/explosive content. The larger/heavier projectile is more suitable for targets like buildings, trenches, bunkers. The larger mass of the projectile steel and larger explosive payload of the 15cm caliber projectiles makes them more suitable for targets requiring destruction instead of suppresion. There is usually a range advantage with the larger caliber cannon tho that is not always the case. Where a significant range advantage is desired tube length and propellant weight are as important as caliber.

The larger caliber SP cannon are heavier & more awkward to manuver, and it requires more transport for their ammo, so they are less suitable for close support of mobile forces. The US Army rejected a 155mm SP for inclusion in the Armored Divsion in WWII. The thinking was that that weapon should be part of the Corps or Army artillery group and attached to the Armored Divsion only when needed. The British moved all medium and heavy artillery from the divsion to the corps/army artillery group in 1938-39.

I have not found any literature relating directly why the Germans included a few 15cm SP cannon in their armored divsion. My best guess is their artillery doctrine made it easier for cmd & control purposes, and the dispersed nature of tactical ops in the East made that more suitable. Until the Hummel appeared only the 10.5 cm cannon were standard to the German Armored Div.

 

Gardners formula is still on the right track for the longer run. The SP have a advantage when extended march off road & they can move into posions that you would think twice about with trucks or horses. Conversely towed cannon & trucks have a large maintiance advantage over tracks, less fuel consumption, and a better overall road mobility.

Horses require far more maintiance than any mechnaized artillery and need a steady supply of grain. They cant sustain road marches from grazing.

 

nobody has mentioned the 95mm C.S howitzers,used in cromwell medium tanks.were they effective?.they would be well forward in any advance,would they not?,any info?.cheers.

 

They were a close support weapon. Not quite inthe same class as these fellows.



Cheers...