Re: [FYI] World's Longest page on tracks vs wheels

Ryan M. Gill wrote:

>>To summarize, the ranter has three main gripes with the LAV-III 8x8:
>>
>>1) It is too heavy to carry in a C-130, at least for long distances. 
>>True. How the former Swedish Coastal Artillery (they've changed their 
>>name after a recent reorganization, but I always forget their new
name) 
>>manage to transport their LAV-III 10x10 up and down the length of
Sweden 
>>in the old RSwAF C-130s I don't know; I suspect they're cheating
somehow <g>
>
>Is it perhaps of lighter construction and limited armor thickness?

Don't think so; all sources I've seen claim that they are standard
LAV-III 
10x10s. (The 10x10 is a couple tons or so heavier than the 8x8 version
the 
US is looking at.) That's why I suspect that the Swedish armed forces
are 
cheating - I just don't know *how* :-/

>>2) Wheeled vehicles don't have the cross-country mobility of tracks.
Also 
>>true, though I find the ranter's repeated comparisons of the LAV-III's

>>mobility with that of French armoured cars from the early 1950s quite 
>>amusing. Technology has advanced somewhat during the past half
century, 
>>even in the wheeled-vehicle transmission field <g>
>
>Well, the ground pressure issue is still the same.

Kinda-sorta. The ground pressure problem hasn't disappeared completely,
but 
with centralized tyre pressure control (you can adjust the pressure of
each 
individual tyre from inside the vehicle) etc. it has been reduced quite
a 
bit for modern wheeled vehicles.

An interesting article from Armor magazine some time ago (don't remember

which issue offhand, but can check): During the UN operation in
Macedonia, 
some of the US posts guarding the Serbian-Macedonian border were
supplied 
by the neighbouring Finnish troops during the snowy period - because the

Finnish SISU wheeled APCs were able to negotiate the snow and get to the

posts, while the US tracked M113s either got stuck or turned into
gigantic 
sleighs (and the weather was too poor for helos to fly out to the posts)
:-/

>50's and 60's Armoured cars are a good comparison to the M113 given
their 
>relative common 'birth dates'.

They're a good comparison to the original M113, sure. Not so sure that 
they're a good comparison for the M113A3 or the LAV-III, both of which
are 
rather more modern :-/

>>3) The gripe which gets the most attention on the page is the claim
that 
>>the LAV-III has vastly inferior protection than the vehicle the ranter

>>pits as its rival, the M113A3. Here he is quite wrong, and presents an

>>impressive array of misleading data; I hope that he is being misled by

>>them rather than attempting to mislead others. Let's take a closer
look 
>>at this gripe:
>
>I agree here. You can make a more heavily armoured Armoured Car. ie the

>Italain Centauro (25 Tons) and South Africa's105mm armed Rooikat AC.
They 
>aren't MBT class, but better than the M113 or the LAV for that matter.

Well, yes. But my main point is that the web site author says "14mm
armour 
on the LAV and 38-44mm armour on the M113A3, therefore the M113A3 is 
obviously vastly better protected" without realising that 14mm sloped
high 
hardness steel gives a very similar level of protection against small
arms 
fire and shrapnel as 38mm vertical aluminium alloy gives :-/

>The maintenance issue with tracks vs wheels has come way down with the 
>newer technology tracks.

Does the latest M113s have the newest tracks, though?

>  Tensioning a bunch of tracks wouldn't be so bad, but they still take
a 
> lot of work when you have to change one or replace one. I could
probably 
> change a tire on the Ferret if I had to by myself. I couldn't do a
M113's 
> track by myself. I do however wonder about how many lubrication points

> the M113 has vs each wheel station on the LAV. If the LAV has lots of 
> bevel boxes, that's a lot of stuff to keep topped up.

IIRC it has a central lubrication system, but that may be mere hearsay
so 
don't quote me on that. Even if it is true, I don't know if it works in 
practise :-/

>As far as mine resistance, I'd point to the South African's as experts
in 
>survivable Wheeled vehicles. The Ratel and Buffels both are very mine 
>resistant.

They are also *very* tall compared to other AFVs - their mine resistance

comes mainly from the boat-shaped hull (deflects the blast to the side 
instead of absorbing it) and the high ground clearance.

>>In other words, all it tells us is that somewhere in the LAV-III hull 
>>there is at least one steel plate which is 14mm thick. It doesn't say 
>>*where* this plate is, nor does it say that the entire hull is made
from 
>>a single thickness of such plate. In fact, this *proof* doesn't tell
us 
>>*anything* about the armour configuration of the LAV-III.
>
>Probably the sides or rear. My ferret has 12mm armour on the sides and 
>16mm on the front glacis/turret face.

Could be the front as well - it is much better sloped than the sides and

rear, so would give better protection against horisontal hits even with
the 
same thickness. After all, the glacis plate on an M1A2 Abrams is only
55mm 
thick ;-)

(The Abrams' glacis is however sloped by 80 degrees from the vertical,
so 
the effective armour thickness vs horisontal hits is more than 300mm :-)
)

>National Defense Magazine lists it as 14.5mm ballistic defense.
>
>"Another feature that the Army agreed to trade off by selecting the LAV

>was armor protection, Yakovac explained. He said the Army is satisfied 
>with the 14.5 mm ballistic protection-7.62 mm in the basic steel hull
and 
>a ceramic appliqué added on top."
>
>Thats protection level, not thickness.

Yep. You know this, I know this, but the web site author thinks that the

Army has gotten the "protection against 14.5mm ammo" mixed up with 
"protection by 14mm steel" :-/ (Do you think he'd accept National
Defense 
Magazine as a more reliable source than Driver's Magazine? Or would he
just 
claim that NDM is as gullible as the rest of the Army...?)

IIRC the appliqué won't be permanently fitted though (eg. removed for 
transport).

FWIW, I've seen a demo of ceramic armour vs our 7.62 AP round at ~5
meters. 
Approx. 3mm bare ceramic plate (ie., no front plate etc. to contain the 
shattered ceramic material after the hit) on a 0.5" steel (RHA) plate...

the ceramic plate disintegrated completely, but the steel plate wasn't
even 
scratched :-/

>>But OK; let's assume that the entire LAV-III hull *is* made of a
single 
>>thickness 14mm steel plate. It could be true, though personally I
suspect 
>>that the front plates are thicker than this. The next quote says:
>
>Its not going to be.

Er... Which of the two above statements isn't going to be - the entire
hull 
being made of a single thickness of plate, or the front plates being
thicker?

>>Armour penetration is usually measured in mm RHA, ie. the distance
which 
>>the projectile penetrates into a standard Rolled Homogenous Armour
plate 
>>with a Brinell hardness number in the 350-380 range - I've seen
several 
>>definitions :-/ The higher the number, the harder the metal; the
harder 
>>the metal, the harder a bullet has penetrating it - very simplified,
but 
>>essentially correct for the plate thicknesses and projectile calibers 
>>we're talking about.
>
>*mumble about slope of the armor face*

I got to the main slope effects further down in the original post :-)
And I 
*did* say that the above mention was very simplified <g>

>I agree that this fellow isn't fair and leaves lots of counter
arguments 
>against the M113 out. I'm mostly in favor of the M113 though for the 
>following reasons.
>
>1. Common with the M2/M3 family as well as the MLRS and other United 
>defense systems based on the M113.

AFAIK the Bradley and its derivatives (MLRS, Linebacker, various cargo 
carriers etc.) share very few common parts (if any) with the M113.

>2. Smaller and more compact, thus smaller target.

Agreed. Smaller size also makes it easier to transport.

>3. Tracks allow better mobility with lower ground pressure in nasty
conditions

Agreed. But see the SISU vs M113 anecdote above in this post <g>

>4. Long time history in the Inventory allows for better institutional 
>knowledge and history. (if it ain't broke, don't fix it).
>5. Band tracks have fixed most of the complaints against tracks.

Does the M113A3 have band tracks?

>Armor protection is pretty much common with both, so I don't really see

>the armor issue being a major factor. If its light and air droppable
then 
>it isn't going to be that well armored or that easy to make float (look
at 
>the M2/3 Bradly/Devers).

Interesting - this is the first time I've heard anyone call the M3 
"Devers"... most scouts/ cavalrymen I've talked to refer to it as the 
"Bradley CFV" (as opposed to the M2 Bradley IFV).

If it is light and air droppable, then it is fairly easy to make float 
(floating also requires a relatively light vehicle). AFAIK the Bradley
is 
neither airdroppable nor amphibious, though - OK, they used to say that
it 
can swim, but the swim gear was withdrawn from service to prevent anyone

from actually trying to use it <g>

Later,

Oerjan
oerjan.ohlson@telia.com

"Life is like a sewer.
  What you get out of it, depends on what you put into it."
-Hen3ry