Armor Penetration Booklet Status

[rexford]

Just a short note to advise interested parties of booklet status.

Booklet is undergoing final revisions and should be available within a month. New information became available on layered armor from Navy source, which allows those T34 and KV-I add-ons (scrap on T34 front, 30mm on KV-I hull front) to be analyzed a little better. Churchill front also has layered armor. And PzKpfw IIIH, Sherman Jumbo and many others.

In splitting hairs department, U.S. 3" and 76mm APCBC have slightly different penetration performance, and this will be considered.

And when 17 pounder APCBC hits medium flaw Panther glacis, quality multiplier is about 0.93, so no penetrations at point blank. 0.85 is medium flaw multiplier for 122mm ammo against Panther glacis. Although Panther glacis armor might crack inside 200m range after defeating 17 pounder APCBC hits, which makes armor susceptible to follow-up hits near the crack.

And data supporting idea that while Panther glacis could lose penetration resistance, rest of armor was good quality most of time. We collected firing test data and compared penetration at range to effective armor resistance, an dit usually matched pretty closely at penetration range.

And booklet data/analysis closely matches the penetration ranges at Kubinka, where 88L71, 100mm APBC and 122mm APBC were fired at Panther glacis.

Will post table of contents soon.

Trying to obtain mailing address for booklet in Rexford, New York, as final touch.

[kipanderson]

Rexford, hi,

I am one of those that is very interested in these matters and so will be keen for a copy of anything you come up with.

Please keep us informed.

All the best,

Kip.

[Ari Maenpaa]

I second Kip's comments.

Keep up the good work.

Ari

[LynnL53]

I too, also am interested in the booklet.

[:USERNAME:]

Will Hare Krishnas be distributing your booklet at airports?

[aka_tom_w]

I know This might sound sort of capitalistic

BUT....

Why don't you sell it?

Are you "permitted" to sell it?

I would like to have a copy as well and would be thrilled to get it for free, but I would be happy to pay for it or a the very least for shipping, or is a really just a digital spread sheet or .pdf file?

Thanks

-tom w

[This message has been edited by aka_tom_w (edited 03-01-2001).]

[This message has been edited by aka_tom_w (edited 03-01-2001).]

[armornut]

I like this idea! I will be looking for more, and I too would be willing to pay a bit for such a jew of information.

Armornut

[Jasper]

I'll supply some web space for it, if you want. Drop me an email to:

funfacts20001@yahoo.com

[John Kelly]

Rexford, I'll be your first customer. What is the anticipated cost of the booklet? John

[Mattias]

Thanks for the update Rex!

M.

[rexford]

We'll be selling the booklet by mail, it will be thermo-bound and about 160 pages.

60% of pages are text, rest is graphs, tables and drawings.

Book compares DeMarre equation estimates with National Physics Laboratory (NPL) equation, finds they are about equivalent in terms of estimated penetration ratio's for APCBC as velocity increases.

DeMarre equation is easier to use.

We're still trying to figure out cost.

Analysis of U.S. penetration data using DeMarre equation shows that most American APCBC very prone to nose damage above certain velocities.

The book is basically a method to predict penetration ranges, and includes many things that are not in CM. Tank armor (angle and thickness) is presented for alot of tanks and self-propelled, giving type (cast, face-hardened, high flaw chance, high hardness, etc.).

Face-hardened penetration data is in there for Allied and Russian ammo. Just found out that Tiger II had face-hardened armor in some critical areas, which joins Panther A & D and alot of other panzers that carried face-hardened armor.

Book uses penetration test data against armor equal to U.S./British test plate, and then converts armor resistance to same base.

When we couldn't find data we estimated it using DeMarre equation,and then tested the results against test firing data and battlefield reports. Our 122mm AP penetration data matches up very well with Russian Military Zone reports versus Panther, and our 88L71 and 100mm APBC penetration/slope effect estimates almost exactly match the penetration ranges against Panther during Kubinka tests.

Our data also matches up very well with British tests with 37mm, 2 pounder, 6 pounder and 75mm against desert panzers using face-hardened armor, and 6 pounder APCBC/APDS and 17 pounder APCBC/APDS against Tiger.

The book has alot of penetration range data compared to booklet predictions, as well as studies that show that Tiger and Panther armor (except for glacis) was equal in resistance to U.S./British penetration test plate, which allows direct comparison between TM-9-1907 penetration data and German armor.

We'll post cost and mailing address data when it is available, probably during in a few weeks or early April.

Thanks for interest.

[Paul Lakowski]

I certainly look forward to the book too. For years I've been quoting Robert to any one whole cares to listen, now I can refer to a book ....always sounds better that way

However we differ on a couple of points.

I've been looking at penetration and armor resistance for years in both modern and WW-II context. I've come to the conclusion that estimating relative projectile plate interaction from the POV of the armor is a mistake and misleading.

The success or failure is dependant on the relation between these two. In some cases deficency in the projectile are a factor while in other cases its flaws or hardness in the plate.In some case the flaws in the projectile or plate don't enter into the equation ...because they don't reach that level.

I find it easier to explain by using the modifications to adjust both projectile penetration and plate resistance if needs be.

So for example I don't use your 'slope modifiers', I use reduction to the projectile efficence at angle.....still have too factor in 'T/d' though. Thats not so easy as there's not a lot of engineering data in this area, but it can be done.

[rexford]

The deciding factor is how well a system predicts what actually happens, and our book will provide LOTS of firing test data against tanks where the actual penetration range matches our prediction. This verifies the general validity of our methods and data.

Projectile penetration may vary, and there is a penetration probability section that goes into this.

With our data and methods, we can explain the results at Kubinka against Panther glacis with 88L71, 100mm APBC and 122mm APBC.

It is far simpler to determine slope effects on the basis of angle, projectile type and T/D than to use other approaches, and our results produce close agreement with actual tests and battlefield reports.

The booklet will allow penetration range estimation, and backs up the methods and data with supporting data based on firing tests against captured tanks and battlefield data. The results should be more dependable than anything else currently available.

We expect that CM may be revised after our booklet is out. Please see my recent post on APDS slope effects for one example that comes from comparing CM data to our booklet information.

[rexford]

The booklet will have flaw factors that reduce armor resistance, and penetration probability will be based on one of two tables which reflect random variations in armor and projectile quality.

The booklet will provide info consistent with other approaches to penetration analysis, although in a different format.