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Armor/AFV: Modern Armor
Modern armor in general.
Hosted by Darren Baker
All things HEMTT...
165thspc
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Posted: Tuesday, August 06, 2019 - 05:17 PM UTC
I think Gino is doing a scratch conversion of an A2 to an A3. There are some photos on this site somewhere. I will try to find them.







Photos found online:
165thspc
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Posted: Tuesday, August 06, 2019 - 05:32 PM UTC
The A3 will require the Oshkosh TAK-4 modular suspension which is available on the HobbyBoss Mk23 Cargo Truck kit as well as on any number of Oshkosh built MRAP models already on the market.



165thspc
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Posted: Tuesday, August 06, 2019 - 05:35 PM UTC
Plus the scratch building of several large electric motors to power these tandem axle units.

HeavyArty
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Posted: Wednesday, August 07, 2019 - 12:03 AM UTC

Quoted Text

I think Gino is doing a scratch conversion of an A2 to an A3.



Not I. I did a scratch/conversion of an M1074 PLS.


165thspc
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Posted: Wednesday, August 07, 2019 - 12:36 AM UTC
Well now I am stumped. Someone is working on an A3 but now I really don't know who!
165thspc
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Posted: Thursday, August 08, 2019 - 12:13 AM UTC


Not sure just how many electric motors are required. I would think only two but perhaps four?????
165thspc
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Posted: Thursday, August 08, 2019 - 12:17 AM UTC
The hybrid system is perfect for defensive weapons requiring a large electrical power source.



.
165thspc
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Posted: Thursday, August 08, 2019 - 02:40 AM UTC
Other A3's in action:


I hope that big fiberglass snout as seen above does not get adopted - Ugly IMHO.

.



Without all that space that used to be given over in the cab for ventilation tunnels to cool that big central mounted radiator employed by the original HEMTT there is a lot more room. Seating now for 3-4, physically cooler cab environment and much roomier!
165thspc
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Posted: Thursday, August 08, 2019 - 03:32 AM UTC
Question answered: The A3 utilizes a total of four electric motors, one per axle. This 4 up motor design certainly saves on mechanical parts in the driveline. Also remember, an electric motor generates its' greatest torque at ZERO RPM!

So massive low end torque, great power, fewer moving parts, improved gas millage, the entire vehicle rides 16" lower than a standard HEMTT and it can move silently for moderate distances running only on capacitor power.

I have had some experience with electric vehicles in my 20 years working for Square D/Groupe Schneider - IMHO I still don't have much faith in the ALL electric (battery) designed vehicles (a.k.a. Tesla, Frisker, etc.) but with this hybrid technology and using capacitors rather than batteries I am 100% all in! It is the real wave of the future and I just wish the Army would go ahead and pull the trigger on adopting this technology.
Trisaw
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Posted: Thursday, August 08, 2019 - 01:02 PM UTC

Quoted Text

The hybrid system is perfect for defensive weapons requiring a large electrical power source.



.



I can think of several new SHORAD versions for the HEMTT besides the ones shown here now that the US DoD has made new weapons systems. Adding the Phalanx 20mm CIWS to the HEMTT was a very good idea and video shows that this worked for base protection.
165thspc
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Posted: Friday, August 09, 2019 - 01:20 AM UTC
More "beauty" shots of the A3:

165thspc
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Posted: Friday, August 09, 2019 - 01:25 AM UTC
I wish Oshkosh would publish a side by side ride height comparison shot between the standard A4 HEMTT LHS carrying a container on a flatrack and the A3 LHS using a Container Handling Unit (CHU) to carry the same container. That would be a 29" reduction in load height (center of gravity.)


A3 electric HEMTT LHS with CHU.


Standard A2 or A4 LHS with flatrack and container.
(Note extreme difference in load height.)
165thspc
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Posted: Friday, August 09, 2019 - 01:34 AM UTC
My main question on the electrics would be: Just how EMP resistant would the A3 electric HEMTT be? But to that I would add another question; with all the modern computerized engine controls how EMP resistant would any military vehicle built today be in that sort of combat environment?????
165thspc
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Posted: Friday, August 09, 2019 - 01:42 AM UTC
I am doing a lot of talking about the A3 electric HEMTT's - perhaps I should now step off my personal soapbox?
Is this too much talk on one sub-topic? Or perhaps I should spin it off to its' own thread?

Opinions?
Dragon164
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Posted: Friday, August 09, 2019 - 05:55 AM UTC
I find it interesting!

Cheers Rob.
LonCray
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Posted: Friday, August 09, 2019 - 06:44 AM UTC
It might be meaningless, but the pictures of the machine with the big ugly fibreglass snout ALSO have a different windshield as well. Is that just a prototype Oshkosh thing or is it otherwise different from the other machines in other ways?
18Bravo
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Posted: Friday, August 09, 2019 - 06:53 AM UTC

Quoted Text

Well now I am stumped. Someone is working on an A3 but now I really don't know who!



I don't remember either, but I sent them a walk around. I'd check my email but I sent it through wetransfer.com. I'm sure someone will fess up.
165thspc
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Posted: Saturday, August 10, 2019 - 02:56 AM UTC

Quoted Text

It might be meaningless, but the pictures of the machine with the big ugly fibreglass snout ALSO have a different windshield as well. Is that just a prototype Oshkosh thing or is it otherwise different from the other machines in other ways?



Honestly I didn't see a difference until you mentioned it. Now I am not so sure. I always though it was just the standard HEMTT cab with either a fibreglass or sheet metal body panel thrown over the old radiator vents.

I do think it is interesting that the A4 has now gone to a side mounted radiator so the "special" A3 cab design has now become the production standard for the entire HEMTT line. Of course that radiator has now also become a very available "soft" sniper target to easily disable the vehicle.
165thspc
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Posted: Saturday, August 10, 2019 - 08:26 AM UTC


165thspc
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Posted: Saturday, August 10, 2019 - 08:32 AM UTC
A minor detail enhancement that is easy to add to the Italeri and Trumpeter LHS kits:

Drill one small hole and fabricate a locking pin and the LHS parts AS MOLDED will let you duplicate this fold down height reducing feature present on the real vehicle.




Photos shown here illustrate this LHS feature modification as installed on my Mk23 LHS 8x8. I had not yet learned this trick earlier while building the HEMTT LHS.
165thspc
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Posted: Saturday, August 10, 2019 - 07:06 PM UTC
Here is an interesting video posted some time ago by arleighburke:

First of all it shows a HEMTT LHS with a mid-ships mounted crane - something I thought was not possible. The HEMTT is loading a folding bridge system that is at least partially containerized and functions and loads using the standard LHS system.

Hummmmmmm - a very interesting load !*!*!*!*!*!*!*!*!*!

https://www.youtube.com/watch?v=LR0q6MykzHk



165thspc
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Posted: Sunday, August 11, 2019 - 06:04 AM UTC
MY BAD! That bridge section is being carried on a standard flatrack. I thought the rack hardware was maybe built right into the bridge section.

Still a very interesting load that would be doable as a scratch build.
165thspc
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Posted: Monday, August 12, 2019 - 07:53 AM UTC
Trying now to get a spec sheet from this Canadian company "EPR Logistics" on their S80 T bridging system but their e-mail does not seen to be working??????
Frenchy
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Posted: Monday, August 12, 2019 - 10:11 AM UTC
This reminds me of the REBS (Rapidly Emplaced Bridge System)





https://www.army-technology.com/projects/rebs-rapidly-emplaced-bridge-system/

H.P.
DJR1971AUS
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Posted: Monday, September 02, 2019 - 06:06 PM UTC
Thanks all for the great A3 info. Especially Michael and others with the photos which I hadn't come across before, all of which answered most of my questions on the differences.

Seems the conversion is a bit more involved than I thought, with the drive motors and changes to the cab, etc, but I'd rather get it right than miss something obvious.

I'll ensure I post pics of my one when I get into it.

Darren