TOT arty fires

[Andreas]

Originally posted by Michael Dorosh:

So after Jon S, Andreas, Jason C, and John D. Salt abandon attempts at discussion with him, umm, how many grogs does he have to go through before he just goes away?

If it isn't obvious by now that he's

a) making this stuff up just to aggravate, or,

even more frighteningly, honestly convinced of what he's saying...

when will it be?

He won't - he will just be convinced that we've given up because he is right. So therefore he has won, in his own mind.

I look forward to the grog deathmatch. Lewis v. Blue Division (Cabron?). Only funny though if Lewis has had a bad day producing his bulldozer simulator (from which he makes US$400/day, as he told us), and BD is off his meds.

[flamingknives]

Despite having changed his position about half a dozen times as successive points have been disproved. I note that now he's trying to claim that the 25pr. was an entirely inferior artillery piece.

Of course, he knows better than every branch of commonwealth artillery, the Germans and the Italians and every historian who's claimed that it was a good piece.

[Wartgamer]

This was the data I wanted to posrt earlier but cut and paste the incorrect data from the same website.

Blast Injuries

The blast pressures necessary to cause injury to the lungs are only likely to be experienced close to the burst of large bombs at distances where severe or fatal injuries from fragments are almost certain to occur. Since artillery shells have a very much lower charge-weight ratio than bombs (a 155 mm. shell only contains 4.8 pounds of explosive{note: author probably means a 105mm), the chances of receiving blast injuries to the lungs without serious fragment injuries are even more unlikely from shellfire than from bombs.

There is no reliable evidence that so-called blast concussion is a direct consequence of the impact of a blast wave on the head. Cranial symptoms, amnesia, and mental confusion are probably due to blows on the head from flying debris or from sudden body displacement. Rupture of the eardrums, however, occurs at very much lower blast pressures than does lung damage, and it is the most sensitive indicator of injury due to blast. In the group of casualties surveyed, there were no instances of damage to the lungs. In 15 casualties, one or both eardrums had been ruptured. Of these men, 11 had also received other injuries from fragments and only 4 had ruptured eardrums as their sole injury.

Of these 15 casualties, 13 were standing erect or had their head and shoulders exposed when they were injured. The other two, although apparently lying protected in slit trenches, were also close enough to the shellburst to experience earth movement, displacement, and partial burial by loose earth nearby. The stated distances (in feet) at which the casualties sustained a blast injury from bursting projectiles is as follows:

Number of casualties

Distance from burst (feet):

0-5 9

5-10 2

10-15 1

15-20 1

20-25 1

Unknown 1

Total

15

It is a remarkable fact that 11 of the 15 casualties were within 10 feet of bursting projectiles and sustained injury due to blast but escaped fatal fragmentation wounds.

The study was a group of 100 casualties. From a lethality standpoint, blast is negligible. From a casualty producing agent; it is not. It is clearly additive to fragmentation in many cases.

There are also many effects and other non-treated injuries that HE blast causes. Partial deafness, nervous conditions, bruisin, etc.

[Wartgamer]

Originally posted by flamingknives:

Despite having changed his position about half a dozen times as successive points have been disproved. I note that now he's trying to claim that the 25pr. was an entirely inferior artillery piece.

Of course, he knows better than every branch of commonwealth artillery, the Germans and the Italians and every historian who's claimed that it was a good piece.

It was a quite good piece. Unfortunately, it had an inferior shell. But I suspect that you are actually practising what you are accusing me off. You are in denial.

The 25 pounder had a 7% payload. I would like to know what its shell wall thickness was (hopefully it was cast iron).

[Wartgamer]

www.aapmr.org/zdocs/assembly/04handouts/C168_4.pdf

In any discussion, modern research should also be taken into account.

It seems that mild concussions/brain injuries were not well understood and 'shell-shock' may actually have been a physical injury.

Given this, many blast events in a short duration certainly would have an adverse effect. It is very analogous to being struck by a flurry of punches.

Note also that HE displaces bodies. The body is actually benefitted by 'going' with the blast wave. If it were rigid (like being up against a wall), it would suffer considerably. But getting thrown and having ones momentum traveling in one direction, and then being met by another blast wave coming at you, is very bad news. When could this happen? Why during a TOT artillery barrage!

There is also speculation that people who died from the medical condition Shock (not to be confused with shell shock), may actually have had multiple injuries from HE including internal ones. Most WWII treatment and surveys focused on what they knew at the time. People going into shock and dying was a possible effect of unkbown HE effects.

http://www.tpub.com/content/combat/14234/css/14234_253.htm

[ April 15, 2005, 12:49 PM: Message edited by: Wartgamer ]

[Wartgamer]

He won't - he will just be convinced that we've given up because he is right. So therefore he has won, in his own mind.

Or maybe the irritable old foul mouthed guy will stick to WWII era data and act like an expert.

More than likely, since data supporting my theories exist, the typical self-congratulating CW responce will be more butt-blown-smoke and hand waving and scoffing.

Speaking of which, I read where the TOT was probably the best method for using the US type of chemical smoke. The burning kind.

The 4.2 apparently could kill through concussion when troops were in caves. It could certainly throw troops into the air.

Lt Thomas R. Blackburn, 26, of Las Animas, Colorado, who commands a platoon, was forward observer. His OP was 250 yards from the Japs. "When our white phosphorus hit into their well-fortified positions, I could hear the Japs screaming, then see some of them running out of their holes. I called for high explosive and where a group would be running before, they would disintegrate with the burst.

We cut them down as they ran. I went over there afterwards and their clothes were burned off. Some bodies were incinerated. I picked up a Japanese carbine and pulled back the bolt-a thin wisp of pungent white phosphorus smoke drifted out. It had permeated everything. In the area were 212 Jap bodies- we couldn't count some. Bodies were hanging in trees, and splattered on rocks. In some caves Japs were huddled in a sitting position, their hands to their ears, no marks on them. I guess they died of concussion.

[ April 16, 2005, 04:16 PM: Message edited by: Wartgamer ]

[Wartgamer]

Here we see that being in a tank, immune from fragments, but still vulnerable to the concussive effects of artillery.

A-41st Tank Battalion

Within an hour, the command tank was hit by an artillery shell. The company commander, Capt. Gardner, was killed instantly and Cpl. Rice hit by shell fragments, causing serious wounds. Tec 4 Sterlacci and Pfc Hunter, in the tank at the time, were sent to the rear, suffering from concussion and shock. Tec 4 Goldman was unhurt. Lt. Scott assumed command of the company and reorganized us. Men were shifted to utilize all tanks, regardless of whether they had full crews

Here we have another concussion type effect..a super CW grenade?

Extract of 4th Para Sqn War Diary September 1944

"Sapper Bromilow was the first to see them and threw a grenade but because the Germans were so close it landed behind them which drove them forward. I jumped out of my trench as I believe it's better to be on the deck in these situations, I saw a group of four or five Germans around a machine gun that had jammed. They hadn't seen me, so from behind a tree I pulled a grenade and waited a couple of seconds before lobbing it underarm. It exploded above their heads and killed three of them instantly. I later went to search the Germans and one was still alive, the others didn't appear to have a mark on them and must have been killed by the concussion of the explosion. The one that was still alive gave me a tin of English cigarettes, he had a large wound on his leg so I tried to drag him back for medical help but he died before I could get him any. Someone else noticed that he also had a bad stomach wound, I personally found the Germans a most chivalrous opponent"

Landmine selective concussion..

It was at about this time, too, that an event occurred that has always made me wonder about life and about destiny. Bob Brook, who had been my roommate and closest buddy at Indiantown Gap and in England, was riding in a jeep with three others when the jeep ran over a land mine. Bob was killed by the concussion, or so they said, but there was not a mark on his body, and not one of the others in the jeep was hurt. Killed on the second day after we landed, he was the first casualty in our entire division.

[ April 17, 2005, 11:37 AM: Message edited by: Wartgamer ]

[flamingknives]

Originally posted by Wartgamer:

</font><blockquote>quote:</font><hr />Originally posted by flamingknives:

Despite having changed his position about half a dozen times as successive points have been disproved. I note that now he's trying to claim that the 25pr. was an entirely inferior artillery piece.

Of course, he knows better than every branch of commonwealth artillery, the Germans and the Italians and every historian who's claimed that it was a good piece.

It was a quite good piece. Unfortunately, it had an inferior shell. But I suspect that you are actually practising what you are accusing me off. You are in denial.

The 25 pounder had a 7% payload. I would like to know what its shell wall thickness was (hopefully it was cast iron). </font>

[Wartgamer]

So what was the 25 pounder's intended task? Certainly not blast. Was it supposed to make large fragments?

As far as asphixiation, it would only be possible if the Japanese were knocked unconcious first. They were found sitting with thier hands over thier ears.

As far as the guy in the jeep, he was more than likely closest to the wheel that struck the mine. The body of the jeep acted as a blast shield for everyone else in the jeep more than likely.

The air burst of a hand grenade (grenades do not generally make supersonic microsplinters) is interesting.

Weapons with thin walls and large HE payloads will make such fine splinters.

[ April 17, 2005, 02:21 PM: Message edited by: Wartgamer ]

[flamingknives]

In common with all field artillery calibres, it can be safely stated that the 25pr. was not intended to cause casualties by blast. In common with most, if not all, high trajectory artillery, it was intended to create primary fragmentation from the shell casing and secondary fragmentation from whatever it hit. Size of fragments I don't know, but I guess that the primary function was to suppress and kill (in that order of priority) the enemy, allowing the infantry to close with and kill the enemy.

[Wartgamer]

The standard shell for all guns was HE and its standard weight was when fitted with a standard fuze. However, different fuzes had slightly different weights while different types of filling could result in significantly different weights. For example 25-pdr BE smoke Mk 2D (see below) was only about 21 lb 13 oz, while 25-pdr armour piercing shot was only 20 lb.

HE shells were the most common and until early 1945 the explosive filling was either TNT or Amatol, the latter having been accepted as the standard between the wars. TNT was less powerful than Lyddite (basically picric acid) that had been discovered in 1886 and widely used in WW1, but was more stable and less sensitive (harder to detonate including by sympathetic detonation). Amatol was a mixture of ammonium nitrate and TNT, with the ratio expressed as 80/20, 60/40 (the standard mix for general use), etc, where the first figure was the proportion of ammonium nitrate, which could be synthetically manufactured. However, in late 1944 a new and more powerful fill was adopted for shells - RDX/TNT and started to appear in small quantities in 1945, the reason for its introduction was improved fragmentation for anti-personnel effects. RDX (also called cyclonite or hexagen) was a more powerful explosive, about 70% more powerful than TNT, discovered in 1899. However, it was difficult to mass produce with quality and this limited its use until joint Canadian, British and US chemical engineering efforts achieved success in 1943. RDX/TNT remained the preferred British artillery fill for the remainder of the 20th Century.

Needless to say HE shell design is not a simple matter, the strength of the steel body has to be balanced with the quantity, power and violence of the explosive to produce the desired fragmentation. The shell body has to be strong enough to withstand the firing forces, either by having thicker walls or using stronger steel. Of course thinner walls means the shell is lighter so either more propellant is needed to achieve the required range or the shell has to be longer to increase the weight. The best anti-personnel fragmentation, fragments about 1/25 oz, requires about 25% of the shell weight to be explosive, which was never achieved in WW2. However, these small fragments don't go as far as larger ones. Cast iron mortar bombs were limited in their HE content because too much causes the body to disintegrate instead of fragmenting.

Of the many types of HE only a few were used with artillery projectiles. The key requirements are power ( the amount of gas for a given weight of explosive) and violence (sometimes called brissance, the rate at which gases are produced). Violence is approximated by the velocity of detonation. There are several approaches to measuring relative explosive power but the British used the Lead Block Test and gave Lyddite a value of 100. Another key requirement is insensitivity, and the British again used Lyddite with a value of 100 for comparison, higher is better. Other requirements are a low tendency to sympathetic detonation, high stability in storage (explosives can react with metals or moisture), high melting point (ammunition can get hot in the sun) and low cost. The following table shows the key characteristics of some of the HE used by the British.

Table 3 - Some HE Characteristics

Lyddite

TNT

Amatol 80/20

Amatol 60/40

Baratol 20/80

RDX/TNT 60/40

Pentolite 50/50

Power

100

95

120

114

80

125

115

VoD (ft/sec)

7250

6950

5080

6470

4600

7600

7455

Sensitivity

100

115

120

115

101

100

70 - 90

'Raw' RDX has a power of 167, VoD 8400 ft/sec and sensitivity of 60 - 65. This meant it had to be desensitised for use in artillery shells, which reduced its power and violence as well as sensitivity. PETN was even more sensitive, 40, and until 1939 had been expensive, Pentolite was a mix of PETN and TNT and used in 40-mm AA shells. Baratol was a mix of TNT and Barium Nitrate, it was used in munitions such as anti-tank gun shells and 2-inch mortar bombs that were expected to encounter poor handling and storage by the users in harsh and wet conditions. Some Shellite, a modified from of Lydite, was also used. RDX/TNT filled 25-pdr was about 20% more lethal than TNT filled and 60% more than Amatol 80/20.

Both TNT and Amatol were difficult to detonate and did not give off any smoke when they did so, which often made ranging difficult. This meant that the explosive in the fuze had to be boosted by use of exploders and a smoke compound added to help observers see a shell's burst.