Canada's tanks

[Kirkhill]

Yup. I wasn't blaming you. I just thought the article might be off base.

When I looked at the photos in the first article I thought I saw a typical tank back deck on the tank which simply can't work with a personnel carrier of any type (unless you have them dismount from the front ). so I looked for other articles and they didn't talk about common chassis.

You're right - and I agree - you can't tell commonality from a few pictures. The Leo chassis and the PzH 2000's are frequently touted as being the same chassis, just reversed back to front. They're actually a bit different but it's always possible that's what we're seeing here.

I've always been of the view that one should have a common tracked chassis for one's tank, IFV and SP (and related admin vehicles). That's hard to do when you look at weight differences and the need for a more powerful engine on a tank, in general (unless you go the middle weight, lowered armour route). If nothing else, needless fuel consumption becomes an issue.

I wasn't too fond of Booker. It's just asking to be used as a tank. Bill Owen suggests a cavalry model that uses lighter medium-like AFVs with a 105 or 120 as the "heavy cavalry" component of an army but stresses that "you can't use them like tanks." There's a cost reason for going to "mediums." But, "mediums" may make a decent tank destroyer during a defensive phase operation, but you loose out on offensive capability that can't be replaced well by other things in the inventory. I can see a "medium" as a direct-fire support vehicle to a predominantly infantry-based force (like an infantry division) but even there, much of a "medium" tanks role, in the defence, can now be performed just as well with a Javelin or other lighter weapons. In the offense . . . ???

I still see a role (nay a need) for a "heavy" tank (although maybe 10-15 tons lighter would be nice) together with a heavier IFV (for extra armour and to share a common power plant). Whether the "tank" goes to a front engine or the IFV goes to a reversed tank chassis is immaterial to me - that's an engineering issue and may be decided by something as mundane as heat/exhaust shimmer from the front engine of a front-engine tank creating issues for the tanks optics/sensors. But you need a tank to do offensive tanky things and not just a tank destroyer/direct fire support things.

I'm looking forward to more info on these Chinese vehicles to see if there is something worth copying here.

Actually, isn't that the reverse of the pre-war British plan? IIRC the Matilda was the infantry support tank and it was more heavily protected than the cavalry's cruisers.

 

[FJAG]

Actually, isn't that the reverse of the pre-war British plan? IIRC the Matilda was the infantry support tank and it was more heavily protected than the cavalry's cruisers.

Wikipedia gives a Coles Notes of that.

Matilda II - Wikipedia

en.wikipedia.org

Cruiser tank - Wikipedia

en.wikipedia.org

 

[KevinB]

Posted with the usual caveats about the reliability of AI in answering questions, I asked ChatGPT the following:

"list the main challenges and disadvantages of designing a main battle tank with the engine in the front of the vehicle" and here's the response that was generated:

I'd throw a lot of the AI "answers" into the rubbish bin.

(*I've noticed most of the companies doing it prefer that term, as opposed to 3D Printing, and they call traditional manufacturing to be 'Subtractive Manufacturing' - which sort of makes sense when you look at the processes).

• Heat and Noise: The engine generates significant heat and noise, which can make the crew compartment hotter, noisier, and more uncomfortable, especially for long-duration missions.
• Toxic Fumes: Improper sealing or damage could allow exhaust or fuel fumes to enter the crew area, affecting health and operational efficiency.

Given what can be Additive Manufactured* these days the cooling issue for a front engine is pretty easy to solve. I don't believe it would make the crew compartment hotter or noisier, as

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• Reduced Crew Protection: While the engine can act as a form of additional protection (sacrificial armor), a hit that disables the engine in the front can immobilize the tank before the crew can react or retreat, increasing the chance of a catastrophic kill.
• Fuel and Fire Hazard: The engine in front increases the risk of fuel fires reaching the crew compartment more quickly.
• Vulnerable Transmission System: Having the engine in front typically means the transmission must route power to the rear drive sprockets through a long shaft or complex drivetrain, increasing the number of vulnerable components.

Having the engine in front is simply more frontal armor, a hit that penetrated the front armor without the engine there was going into the crew compartment. Fuel and Fire hazard are no more dangerous than rear, and if a rear exit hatch exists actually provided more protection for the crew as they dont need to abandon over the top and chose from either enemy fire or going near an engine fire.
No idea why anyone would retain the rear drive sprockets if the engine is up front. Furthermore you can have a significant firewall between the crew compartment and the engine.

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• Longer Drivetrain: If the tank retains rear drive sprockets, the drivetrain becomes longer and more complex, reducing efficiency and increasing maintenance needs.
• Weight Distribution Challenges: Tanks are often rear-heavy to balance the large gun and turret at the front. A front engine can unbalancethe vehicle, affecting:
  
  • Mobility and suspension performance
  • Obstacle negotiation (e.g., trench crossing)
• Cooling System Complications: Engine cooling requires large radiators and airflow. Managing this efficiently in the front, without exposing vulnerable components, can be harder to achieve.

I have a tough time understanding why if one foot engines, one wouldn't then put the transmission and drive sprockets up front. I don't see the weight distribution as a major factor - simply as one can ballast the tank to deal with that, when you start with a fresh design you can find a lot of economies in certain areas.
Cooling, well I think that was covered above, but "open top" grill deck engine platforms are a no go in the age of UAS, Loitering Munitions and Smart Attack Munitions, so even future rear engine tanks will have to adopt a lot of new technologies to manage engine heat and exhaust.

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• Reduced Gun Depression: Tanks with forward engines may have higher front hull profiles, potentially limiting gun depression angles over the front arc.
• Higher Silhouette: A front-mounted engine could lead to a larger silhouette, making the tank more visible and easier to target.
• Driver Visibility: The driver’s position may be compromised or obstructed by engine components, reducing forward visibility.

I'm curious where the AI gathered that front engine tanks need to be taller, other than some belief that because most IFV are taller and have front engines, but the height of those is more a factor of the dismounts not being able to fold into a ball - not the engine dictating that. If you can pull the driver back behind the turret - you gain a lot of room for engine placement that doesn't require any significant height. Driver visibility buttoned up in the Abrams is not impressive - and they can't exist with the turret in certain positions - so I can't honestly buy into the visibility aspect.

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• Maintenance Access: Front engine compartments can complicate access to critical engine components due to cramped layout or turret interference.
• Modularity and Upgrade Path: Tanks with rear engines (like the M1 Abrams, Leopard 2, etc.) often have better modular layouts that make upgrades or engine swaps faster in the field.

Now one aspect that is true is that a front engine layout with MBT levels of armor does require a new way to look at tank design, or you end up with massively heavy armor slabs that need to be bolted and unbolted and machine lifted clear to make access feasible, or a significantly powerful hydraulic system to raise a 2t slab of armor in order to get access. You would basically need a plug and play interior "chassis" that was rear removable that could easily decouple from the armor outer hull and be slid back to access the engine and transmission, which would also then allow working on the drive sprockets if necessarily, now that would require either a non penetrating (the hull) turret design, or a segmented turret basket for a turret crew that the lower penetrating part of the basket would separate with the inner chassis .

 

[FJAG]

Second prototype of Leopard 2A-RC 3.0 PT 02 with unmanned turret revealed.

 

[FJAG]

The immediate thought I had with this is to add a fourth crew member within the hull as the weapon operator for the 30mm which ought to have a double feed system for AP rounds and AHEAD. This allows the main gunner and commander to fight the offensive capability of the tank while an unengaged gunner is free to monitor the anti air and anti APC/IFV situation and engage with the 30mm.

As a bonus it adds that additional crew member for sentry duties and maintenance when not engaged.