Mini Abrams...

[lobbie111]

HYPOTHETICALLY would it be possible to lighten and reduce the dimensions of the Abrams or any modern MBT, maybe give it around 3 crew (Gunner, Commander/Loader, Driver) With a 105mm gun plus the standard .50 and 7.62mm machine guns.

Would this be an effective medium/light tank? Could it be used for infantry support and indeed a converted APC variant.

Any comments...

 

[winnyfield]

I don't think it can happen or in the way that your thinking ~ 20t reduction to be consider a success. A lot of the weight is in the hull/chassis (base armour) there won't be much difference by changing the armaments. Also, the Abrams already uses a gas turbine engine that's lighter than a conventional diesel. The Israelis are planning an APC based upon the Merkava but it's still heavy at 45t.

If your looking for a 35-40t vehicle, upgrading an IFV is probably the best way to go (see the CV90 120-T). You don't even need a cannon, a Bradley with TOW missiles is still pretty deadly to MBTs.

 

[lobbie111]

I was more thinking of a medium vehicle to support mechanised infantry with more manouverability and lessweight. The APC thing doesnt really matter just a suggestion really but it has been done before I refer you to the BTMP-84 a variant of the TU-84 Oplot, basically the tank was extended an extra pair of roadwheels on ans could seat 5-6.

What i was thinking of is similar to the M8 Buford.

 

[swerve]

You could build a smaller tank with lighter armament, but it wouldn't be an Abrams or whatever.

As said, the gun isn't the big weight, & removing the loader means you need an autoloader. That can save weight, but it comes from reduced under-armour volume, hence less armour, not the autoloader being lighter than the man it replaces. To lose a lot of weight you have to look at reducing armour, which means making the tank smaller, or less well armoured. Or both.

If you're willing to accept a reduced ammunition load, you could build a tank with the same armour protection as the M1A2, but smaller. Start with the Jordanian Falcon unmanned turret, which has the relatively light 120mm RuAG CTG. 17 rounds in the autoloader & none in the hull, & 3 man crew below the turret ring. Smaller & lighter engine & transmission (note that the gas turbine of the M1 is relatively small & light, but the bits around it aren't: total powerpack & transmission size & weight is what matters here), because less weight to lug around, permitting a slightly smaller & therefore lighter hull.

I reckon you could save at least 10 tons, for the same level of protection. But it still wouldn't be lightweight, & there are tradeoffs, e.g. the reduced ammo load.

If you want a medium/light tank with less armour, then there are IFV variants (e.g. Cv90120-T, with same RuAG gun) on the market.

 

[Chrom]

2 crews and humanless turret would allow about 37-40t tank be better armed & protected than M1A2.

 

[lobbie111]

If only a Puma with a 105-120mm cannon

 

[swerve]

If only a Puma with a 105-120mm cannon

Hull's too big, because it's designed to take several troops. Would need protected volume reduced to allow armour to be improved to the same level as a heavy tank.

You could probably use the automotive components of a Puma, but you'd need to replace almost all of the rest.

 

[Waylander]

And 2 man crew is going to loose a lot of efectiveness compared to a 3 man crew with todays technology.
Driving a tank alone during combat is a full time job. Add to that commanding, shooting, searching for targets, radio operations and maybe control over your platoon/company and you have much too much to do for a 2 men crew.

 

[eckherl]

Please pick the CV120, and leave my tank alone.

 

[rjmaz1]

And 2 man crew is going to loose a lot of efectiveness compared to a 3 man crew with todays technology.
Driving a tank alone during combat is a full time job. Add to that commanding, shooting, searching for targets, radio operations and maybe control over your platoon/company and you have much too much to do for a 2 men crew.

With todays sensor fusion, i believe two people could do the job fine.

Helmet cued gun with a helmet mounted display would significantly reduce the workload in my opinion.

A moving map with all the data placed nicely would reduce the cognitive workload significantly.

In a previously thread i designed a bushmaster tank in photoshop which was pretty cool.

My idea of simplifying a tank is to have the crew seated side by side, wrap around LCD screens providing a view outside. Having IR and Optical camera's and when light levels reduce the screens start overlaying the IR images.

Have a nice big moving map between the two crew members.

By giving the driver excellent situational awareness it allows him to drive with minimal input from the navigator.

The second crew member being the gunner/navigator could use their helmet to aim the gun and control sensors. Automation with other friendly's being displayed on the moving map and even the surround screens would help dramatically.

The side by side cabin would reduce the cabin space to a quarter of the current battle tank. This will push the weight right down to below 40 tone without any capability lost from the M1A2.

If you changed the turret to a 30mm cannon and added a say four anti tank missiles you'd now be reaching close to 30 tone.

By using a hyrbid electric system with electric motors powering each wheel running off batteries recharged by a small diesel engine then you give the tank silent running capabilities and a lower signature allowing it to get closer and lighter again. Now that the weight would be easily under 30 ton it would be possible to go with a 6x6 drive system instead of a tracked vehicle.

You'd now having something with the ability and speed of a humvee with armor of a tank and with its sensor advantage and anti tank missiles it could destroy enemy tanks that were many times heavier.

Though the US army vehicle program will probably use alot of features that i have listed.

 

[Waylander]

This is not going to work.

I said that driving the tank is a fulltime job because of the terrain.
It is just damn difficult to drive a tank with high speed over rough ground without bumping into every ditch. Not to talk of orientating the front to the enemy, not falling behind or outrunning your the other tanks in your platoon.

And a TC is defenitely not going to let his driver planning the route were he wants to go.
The same goes for battle positions. A TC is going to have the better idea of the ideal firing position than the low sitting driver even if you would give the driver some kind of glass cockpit.

The next thing is target aquisition.
Right now the gunner is searching for enemy targets with usually 3x-12x optics. This is defenitely needed to track targets. Others here with experience on AFVs will agree with me that the gunner normally has an awfull low situational awareness and often enough has no clue about were he is.

So you your proposed navigator/gunner faces some big problems.
He may scan for targets with 3x-12x zoom and loose alot of his situational awareness or he may chose the situational awareness with normal 1x glass cockpit but looses alot of his ability to see enemy threats.
When he has to look on his map he can't do even one of the things above.

Another problem is how does one wants to achieve the zoom of 3x-12x with a glass cockpit.
His zoomed view has to be slaved to the main optic because of stabilization with the picture of the GPS projected into his viewfield and so offers little to no advantage over a classical gunner looking into his sight. Not to talk of aiming with a 12x zoom just with the precision of your neck muscles in a rough riding vehicle.

There are just too many things to do.
I know were you are coming from (fighterplanes) but this doesn't work the way you think.
All the guys here with actual experience in fighting with an AFV are going to tell you the same. One needs a minimum of 3 man or otherwise combat effectiveness is reduced significantly.

 

[rjmaz1]

If you significantly improve the situational awareness of the driver then you allow the driver to make navigational decisions and offload the navigator of non tactical decisions. Having greater awareness or field of view of your environment makes it much easier for the driver to avoid bumping into every ditch.

If you significantly improve the situation awareness of the gunner then they will know where abouts they are in relation to their zoomed optic view. The reason why the gunner currently cannot navigate is because they have such a narrow field of view that it would make the job difficult. This is easily fixed in my opinion.

There is some overlap between the gunner, navigator and driver. The driver navigates in close range while the Navigator makes long range navigation etc. If you make the job significantly easier for the driver and gunner then they can take over more navigation functions to the point where the navigator could be eliminated without a noticeable decrease in capability. That slight decrease would be well worth the weight reduction.

Having the zoomed targeting optics overlayed onto the lcd displays allow the gunner to see where his gun is pointed relative to the vehicles position. The zoomed optics could be moved over the normal magnification images using helmet movement of the gunner. The microscope that i am using now can have its image displayed on a computer screen at more than 2000x2000 pixels and the refresh rate is excellent. Fatigue is significantly reduced looking at a lcd screen than staring down a microscope. The gunners situational awareness would dramatically improve to the point where he could take up the longer range and tactical navigational role. However the tactical navigation should and probably already is outsourced to a someone thousands of miles from the battlefield. The driver also being able to see the gunners sights and know where the enemy is will further improve his ability to point/driver the tank in the right direction.

The moving map could even be displayed on the glass cockpit screens.

With the way automation is going i could see the workload being significantly reduced. Some mercedes bends automatically apply the brakes if you get too close to the car in front, technology like this could allow the tank to practically drive itself allowing him to help navigate.

I get where you are coming from that the workload is quite great, but with well thought out automation i think performance would not reduce and the weight/logistic savings would be massive.

 

[Waylander]

If you significantly improve the situational awareness of the driver then you allow the driver to make navigational decisions and offload the navigator of non tactical decisions. This will make it much easier for the driver to avoid bumping into every ditch.

With a tank nearly every movement is a tactical decision (Apart from preplanned (road)marches).
And you don't jump into ditches because you haven't navigated carefully enough but because the terrain is difficult and/or you weren't concentrated enough.
I just can say it again. A driver can drive and that's it.
A glass cockpit may make it easier for him to drive and one may also improve decision making by the driver but it is still a full time job.

If you significantly improve the situation awareness of the gunner then they will know where abouts they are in relation to their zoomed optic view.

There is some overlap between the gunner, navigator and driver. The driver navigates in close range while the Navigator makes long range navigation etc. If you make the job significantly easier for the driver and gunner then they can take over more navigation functions to the point where the navigator could be eliminated without a noticeable decrease in capability. That slight decrease would be well worth the weight reduction.


Having the zoomed targeting optics overlayed onto the lcd displays allow the gunner to see where his gun is pointed relative to the vehicles position. It would dramatically improve his situational awareness to the point where he could take up the longer range and tactical navigational role. However the tactical navigation should and probably already is outsourced to a someone thousands of miles from the battlefield. The driver also being able to see the gunners sights and know where the enemy is will further improve his ability to point/driver the tank in the right direction.

But one can just concentrate so much on one thing. I don't say that it isn't possible to use a 2 man crew. But effectiveness is going to be reduced. Reduced a lot.
Even with overlayed pictures on the displays one has to do share it's concentration and awareness to two nearly totally different tasks.
A TC has to look around a lot while the gunner has to scan his sector. It is just damn difficult to identify targets at that distance even with capable optics and you want to share the available concentration and time between two fulltime jobs.
As for outside tactical navigation. This is exactly the wrong way and every leader is not going to let the tactical decisions be made from a HQ miles away.
This is nearly the total opposite of Auftragstaktik and is the vision of hell for every leader in the field.

The moving map could even be displayed on the glass cockpit screens.

Did you ever performed navigation with the help of a military map? Even in the time of GPS it is not enough to just have a quick look at a displayed map. And while battlefield management systems improve the ability to plan and navigate your movement and the movement of your unit it still needs a lot more than a qhick look. It is bad enough if you jump into the sh** while your TC is reading the map but you are even more screwed if this TC is also your gunner...

With the way automation is going i could see the workload being significantly reduced. Some mercedes bends automatically apply the brakes if you get too close to the car in front, technology like this could.

I get where you are coming from that the workload is quite great, but with well thought out automation i think performance would not reduce and the weight/logistic savings would be massive.

Yeah, I also remember how the ground UAV tests donated by the US MoD looked like.
I also know how for example the new automatic parking for modern cars works.

This is still far away from being what you do with a tank during a fight.

I still don't get what makes you think that the loss of combat effectiveness is insignificant.

I really hate to use the "been there done that" argument and I wait for other members who also served on AFVs to also add their opinion
But I would like to know if you have ever served on an AFV or if you know somebody who did and told you that it shouldn't be a problem?
Because I just have the feeling that you underestimate the special problems which come with fighting with a tank because you tend to directly convert ideas from air combat to ground combat.

 

[Wooki]

Please pick the CV120, and leave my tank alone.

No, no sorry, can't do that Eckherl...lets turn it into an EFV! och, we can use a new SEM system to make it air droppable too. Perfect.

cheers

w

 

[AGRA]

You could pull out all the special armour packages from an M1A1 AIM and/or M1A2 from the turret front and glacis. They are mounted in steel ‘pockets’ that are basically the outer and inner edges of the vehicles exterior wall. This would lower the weight of an M1 by a classified amount but reduce armour protection to just basically bullet proof (~12.7mm). But its not going to be much more than a 10-15 tonne weight saving.

If you want a light tank then design it from scratch and the best way to lower weight is to reduce interior volume, therefore reducing the amount of armour needed for protection. Though the reasons giving by the thread creator would indicate a lack of understanding of actual M1 tank performance and capability. Simple reducing weight is not going to give you significantly more mobility or practical deployability. You want to significantly increase mobility then design a tank with a width of 2m. Such a beast would be able to go places no one else can, like up an alleyway!

The FCS MGV MCS will have a two man crew and a 120mm gun and ammunition of better performance than that on the M1A1/A2. It will achieve tank performance with only two people because like all MGVs it will be able to drive itself, including tactical driving and navigation.

Talk about rebuilding M1A1 AIM and/or M1A2s is looking at fitting a Western Design automatic loader. This will reduce stored rounds from 40 to 34 but free up the loader/operator to be a deputy commander. This crew person will operate a roof top remote controlled machinegun (or 25mm OCSW) and assist the commander in the kind of complex battles of Iraq and so on.

Of course with the MCS the improved means of controlling the tank’s functions and automatic detail control will mean the two person crew will function very much like the commander and “deputy commander” of an M1A3 with the driver, gunner and loader’s roles automated.

 

[rjmaz1]

I really hate to use the "been there done that" argument and I wait for other members who also served on AFVs to also add their opinion
But I would like to know if you have ever served on an AFV or if you know somebody who did and told you that it shouldn't be a problem?
Because I just have the feeling that you underestimate the special problems which come with fighting with a tank because you tend to directly convert ideas from air combat to ground combat.

Well if AGRA's post is correct regarding the next tank only having 2 crew members then you've over estimated the workload or underestimated how far automation technology has progressed.

Technology is progressing so much that current members serving in the armed forced wouldn't have a clue if automation could reduce the number of crew members. The equipment they currently use has little to no automation which would probably come down to money.

If you want a light tank then design it from scratch and the best way to lower weight is to reduce interior volume, therefore reducing the amount of armour needed for protection.

Yep thats the best idea. Two crew members sitting side by side would reduce the volume so much that you've halved the weight right there without a reduction in armor or firepower.

You want to significantly increase mobility then design a tank with a width of 2m. Such a beast would be able to go places no one else can, like up an alleyway!

A two man side by side crew may very well achieve a 2m wide tank. That would be pretty good for mobility

I wouldn't be surprised if the future tanks have the same size footprint of a humvee with the armor and firepower of a M1A2. Weight may reach a third of an M1A2.

You are definitely correct in stating that reducing interior is the only way to reduce weight. Decreased volume reduces the surface area of the armor required reducing weight. This is much better than reducing the thickness of the armor to reduce weight.

Even if there happened to be a 10-20% reduction in capability due to having two crew members the massive logistical advantage of reduced weight and fuel consumption would allow for twice as many vehicles to be used making the overall battalion much more powerful/capable while still maintaining a lower battalion weight.

 

[Waylander]

Yeah, as if one can use the promises of the FCS program as given facts...

This program is known for being fully in time and producing all the new technologies it promised...

Before there isn't a fully working prototype with all the promised features I don't clap my hands for the FCS.
And till than it is still lots of time to go.

I thought we are talking about designing a vehicle now.
If you want FCS (Which is going to be smaller than everything before) you have to wait for FCS.

Future tanks having the footprint of a Humvee with the same firepower and protection?
Of how far in the future do you think we are talking about?
Not that long ago they dropped the C-130 requirement. Makes you think about the "small will be as capable" argument.
And FCS is a lot more ambitious than everything else in this aspect.

As for 10-20% capability gap. These 10-20% may kill you and you don't expect that you field twice as many vehicles of these expensive vehicles just because they are lighter don't you?

What are we talking about here?
What one can achieve with todays (Or the one of the next few years) tech or what one may achieve later in the future?

The new target weight for FCS is round 28 tons because one wants to get 3 of them into a C-17.

But they still want to let the Abrams serve as late as 2050 (With M1A3 upgrade program) in the heavy brigades.
Makes one wonder how much armor protection they really expect from the lightweigth vehicle family...

 

[Sgt.Banes]

It wouldn't be much of a tank with this armour bulk, I think you want to make an APC that's more like a tank or vice versa. The thing that you're shooting for is an IFV or a "Tiny Tank" as I like to call it. But a tank that carries soldiers is a little redundant since then it would be considered an APC. Tanks are designed to be "bulky" for a reason.

 

[gf0012-aust]

This is much better than reducing the thickness of the armor to reduce weight.

Even if there happened to be a 10-20% reduction in capability due to having two crew members the massive logistical advantage of reduced weight and fuel consumption would allow for twice as many vehicles to be used making the overall battalion much more powerful/capable while still maintaining a lower battalion weight.

Well, Wooki is the resident real world armour expert, but there needs to be some clarification here.

Armour thickness is a relative concept, ie, an armour rating is benched against a relative RHA (or appropriate/similar) level. It's not literal.

In addition, the issue of mass as a medium is because its not just an issue of penetration - its also an issue of kinetic effect.

eg. when we did proximity tests for the S600's the armour thickness rating was identical to early Bushmaster but was a different thickness. Thats because the armour type used was of different material. (same STANAG rating, but a different efficiency level wrt absolute thickness)

similarly, when direct fire tests were conducted, a lighter vehicle will be subjected to movement. Enough movement and you start to impact upon the integrity of other equipment like optics, FCS etc... that means changes to acoustic, noise and vibration management - and that means a loss of volume due to more robust bracing.

or to use another example, the direct fire tests of metalstorm against a lighter vehicle resulted in visible movement of mass - when directed against a larger vehicle, less movement was visibly apparent.

There is a reason why you have heavy armoured vehicles, it is not always relevant to reduce it down to an medium lift air transportable package. Change the mass and you change the fundamental options and capability of that platform.

You could literally have 3 platforms with a "declared" RHA of 1100mm but discover that alll 3 are physically very different in thickness of the armour material. The internal volume in simplistic terms would be different for all 3, but not at a significant level. The significant influencer/impediment to increasing volumetric dynamics is protection of the crew and the equipment beyond the first layer (exoskeleton of the platform)

It's not a simple volumetric efficiency/armour rating dynamic.

 

[AGRA]

I thought we are talking about designing a vehicle now.
If you want FCS (Which is going to be smaller than everything before) you have to wait for FCS.

FCS is designing vehicles and systems now and for an initial in service date of 2015ish. Not going to get anything into service quicker than that…

And key technologies are being demonstrated, like the autonomous driving systems and multi-platform sensor fusion. Auto trackers able to do the job of a gunner after target designation by the commander are commonplace and in service in a wide range of applications. Even automatic target identification and prosecution software is common.

Future tanks having the footprint of a Humvee with the same firepower and protection?
Of how far in the future do you think we are talking about?
Not that long ago they dropped the C-130 requirement. Makes you think about the "small will be as capable" argument.
And FCS is a lot more ambitious than everything else in this aspect.

FCS is ambitious because it is not conventional. It is the first combat vehicle designed from the ground up with a hybrid powerplant. Electrical transmission provides huge weight and volume savings. The C-130 requirement was dropped because it was nonsense – the problem is not so much designing a tank to fit inside a C-130 but to be able to get any practical military benefit by operational deployment in a C-130. Now if we had C-130 sized VTOLs that would be different.

The new target weight for FCS is round 28 tons because one wants to get 3 of them into a C-17.

Not at all. Its 27 tonnes because that’s loads of armour and capability for an FCS sized vehicle. You can still strip it down to a 18 tonne configuration for loading into a C-130. But its really meaningless stuff.

But they still want to let the Abrams serve as late as 2050 (With M1A3 upgrade program) in the heavy brigades.
Makes one wonder how much armor protection they really expect from the lightweigth vehicle family...

The FCS will be much better protected than the M1. M1 will remain in service until 2050 because the US will not be buying FCS at a rate fast enough to replace them before this date. Gone are the days of Lima turning out 1,000 M1 tanks a year.

A two man side by side crew may very well achieve a 2m wide tank. That would be pretty good for mobility

Well probably not. But sit those two crew in tandem and you could have a <2m width tank. After the Lebanon War the IDF armor corps feedback process on the Merkava came up with “reduce the width” as one of the strongest desires of the operational tank crews. Of course no one has done anything to reduce the width of tanks since the T-34… the problem being track area and ground pressure.

You are definitely correct in stating that reducing interior is the only way to reduce weight. Decreased volume reduces the surface area of the armor required reducing weight. This is much better than reducing the thickness of the armor to reduce weight.

Well it’s the only way to do it from a design process. Improved lighter weight technology will also reduce weight.

But reducing interior volume was the very successful idea behind Sven Berge’s Strv 103 ‘S-Tank’. By removing the turret and fixing the gun inside the hull they achieved a tank with the same armour thickness, fire power, etc as a Centurion at only 40 tonnes compared to 55 tonnes. Said tank could also be fully operated (moved and gun aimed and fired) in an emergency by only one person. Operational testing by an independent third party – the British Army in the early 1970s – found that removing the turret made no appreciable loss of efficiency in all combat scenarios, including offensive operations.