Half scratch-built tank WIP!

[djizomdjinn]

Superb!

 

Only minor nitpicking on the painted/finished machine... the emblem is very clean.

It would be a little dirtier IMHO.

 

Maybe a small wash over it?

 

Thanks! I was thinking though, that since it's so high up (3 meters in the air?), and one of the few things on it probably cleaned regularly as a point of honor, that not much in the way of dust or dirt would accumulate on it. Maybe rain streaks...

 

Of note, you can now browse all the images from the Dover and Percival projects in one continuous album here. Let me know if it breaks, I'm not sure if imgur's 250 image count applies to albums.

 

I've been scratching my head about this for a few days. Or at least it feels like a few days by now. Measurements put the real-scale tank at a height of 3.8m. 3.8m. That's staggeringly tall. Twelve and a half feet. Not to mention, I read once about a proposal to raise the hull of the Sherman (or some other American WW2 tank) to fit some equipment or other, and Ordnance replied that yes, it could be done, but at a cost of a ton of extra weight per inch raised.

 

Dover II desperately needs a size cut.

 

 

This side engine arrangement is proving more trouble than it's worth. I can understand why Israel did it, they needed a low-cost well-protected APC, they had a bunch of old T-55 hulls, they didn't want to spend too much time and money futzing around with it. But just look at all that wasted space! That entire walkway next to the engine can't be filled with anything, or else the troops can't get out, and it needs to be raised above the rear sprocket axles, which means the floor is ridiculously high, which pushes the ceiling even higher...

 

 

And in a domino effect, the troop compartment pushes the turret forward, which pushes the turret basket forward, which crushes the driver against the glacis plate. Not looking good.

 

 

 

So, like an import sports car, I am shoving the engine into the middle of the tank, between the turret basket and the passenger compartment. Power would be split in a differential right before the passenger compartment, and then diverted to the two sprockets through drive axles running under the passenger benches. Now, with the rearmost axle split in two, the floor of the passenger compartment can be dropped, dropping the ceiling, letting the turret relax a bit, letting the driver relax. End measured result? 3.3m. A half-meter reduction in height just by shuffling things around. If that report was any indication, I just shaved 20 tons off the vehicle.

 

Pros: Vehicle is not stupidly huge, just mildly huge. Passengers have an easier time getting to rear access ramp. Driver can exist.

Cons: Passengers can no longer store stuff under their seat. Crew can no longer bail out through the passenger compartment. Accessing the engine powerpack must be done through the passenger compartment., and doing routine maintenance on the engine probably requires rotating the turret. More extensive maintenance probably needs pulling the turret off the tank. Possibly more fragile drivetrain.

 

 

 

 

 

At one point, I was considering shifting the era this tank would have been built. I was thinking 1960's technology at first, but if I do a 1980's version I can do all sorts of wonderful space saving tricks using computerization, dropping the turret crew into the basket for even better armor protection, etc. What do you guys think?

 

After the war, the Altian military commenced development of a next generation infantry support tank, under the program name of Project ROOK. Firepower was to be provided by a licensed Royal Ordnance L7 105mm cannon, but most importantly, the new vehicle was to have space for transporting a small infantry section. Armor was given the highest priority; mobility and range were deemed to be largely unnecessary in the network of steep river valleys where most fighting took place during the last war. These tanks were intended as defensive tanks, speedy offensive light tanks would be developed under the sister program, Project KNIGHT, to replace the Percival tank destroyer.

 

At first, the vehicle was tentatively named 'Camelot', but the Queen herself took a deep interest in the program and insisted that it be christened the Dover II. Rumor has it that one of the prototype vehicles was repainted in old St. Sophia's Military Academy colors and presented to the royal family as a gift as the first batch of tanks started equipping the armored divisions.

[knarthex]

No Ordinance engineer in his right mind is going to put the power pack where it needs the turret removed before it can be pulled!

 

On the Abrams, and the M60A3 before it, we pulled the power packs every 3 months! All done with the gear that we would have with us in the field. We did do it occasionally in the field....

 

If it just a matter of rotating the turret, not a problem, as we had to do that with both tanks.

 

American tanks have always been built with ease of maintenance in mind, going back to the M2s and such that ended up proving the drive trains and suspensions for the later Grant / Lee and Shermans....

 

Make sure that the driver's hatch is big enough for him to get out of it....

The M1 and M60A3 both had a hatch that big, but if the turret was forward, or reversed, you had better be one real skinny driver!

 

The M60A3 had an escape hatch in the belly under the driver's seat...

 

None on the M1

 

Just some more data from a former CDAT  (Computerized Dumb Elf Tanker)

 

George

[djizomdjinn]

No Ordinance engineer in his right mind is going to put the power pack where it needs the turret removed before it can be pulled!

 

On the Abrams, and the M60A3 before it, we pulled the power packs every 3 months! All done with the gear that we would have with us in the field. We did do it occasionally in the field....

 

If it just a matter of rotating the turret, not a problem, as we had to do that with both tanks.

 

American tanks have always been built with ease of maintenance in mind, going back to the M2s and such that ended up proving the drive trains and suspensions for the later Grant / Lee and Shermans....

 

Make sure that the driver's hatch is big enough for him to get out of it....

The M1 and M60A3 both had a hatch that big, but if the turret was forward, or reversed, you had better be one real skinny driver!

 

The M60A3 had an escape hatch in the belly under the driver's seat...

 

None on the M1

 

Just some more data from a former CDAT  (Computerized Dumb Elf Tanker)

 

George

 

Yeah, I was thinking they could probably pull the power pack through the passenger compartment's front wall. A bit of a pain to do, but the alternative is flipping the tank and going front-engine front-sprocket. Which basically means I've reinvented the Merkava. And where's the fun in that?

 

Depending on how much overhang the turret has in the sides, it may or may not involve pulling the turret for fix-up work. If I drop the gunner and commander into the hull ala M1128 MGS, that'd help with maintenance issues too, especially since I can't think of much else I can put in the turret basket other than another shot locker. The gun can't really be combat-reloaded anyways after it expends all the rounds in the bustle, since autoloader and cleft turret. Similar to the AMX-13 in that respect.

 

About WW2 tanks, there's an interesting quote I read once about a British officer's opinion after a three way comparison of reliability on a 3,000 mile road march. It went something like "I would not want the Centaur tank at all. I would be satisfied to lead a squadron of Cromwells after a few more months of testing and development, and I would be happy to lead a squadron of Shermans to war tomorrow."

 

Driver's hatch will be scooted forwards a bit, but should be fine. (looks up reference). Oh, so that's what that notch on the Leopard 2 turret is for, the driver can't get out otherwise. Should have room for escape hatches; I'm actually not sure what to do with the room under the turret. Fuel, maybe, to augment the external tanks that'll be on each side of the passenger compartment.

 

I am acutely reminded of this video in an attempt to shuffle things around to make some room. Most militaries have seen fit not to cram passenger space into their tanks, and I'm beginning to see why...

[robinh]

Yup sounds like most military acquisitions design meetings!  But to tell the truth the same happens on the Civi side with the various computer software and equipment as well.

[djizomdjinn]

A short update, been taking breaks as to not burn myself out like I did for the first Dover.

 

Raised the front hull a bit to make room for stuff like the driver's legs. Also started building the trunnions for the gun housing, the shape of which can be seen peeking out from under all that blue tape.

 

 

"Cleft turrets have excellent gun depression." No kidding, that's like 30 degrees. Hull-down and reverse-slope defense against pretty much anything. I don't think the infantry inside would appreciate this much though.

 

 

I could have two hatches or one manned station in the turret. I picked one manned station, though I might give it a bustle to fit two people. Also showing off the gun offset, which will be counter-offset by moving the turret ring.

 

[Chaoswolf]

Looking good!

[djizomdjinn]

I swear, I never follow my own plans. But still, making them is important. It gives you a default option you can compare alternatives against.

 

Anyways, turret bustle. Basic underlying form, I'll add details like blowout panels and the shell ejection port later on.

 

 

The funny thing is... I don't know why, maybe it's a coincidence, maybe it's joint US-German tank design, maybe Tamiya wanted to standardize. But the turret ring diameters for the M41 turret and the Leopard 1 turret seem to be identical. Unfortunately they don't work together; on the Leopard the turret has the male flanges, on the M41 it's the hull. But still, I like the shape, and given how gutted it is it's not like I'm going to do anything else with it...

 

But uh, first I had to tear off the commander's hatch / cupola I'd welded on last update. Whoops. At least the weld scars are hidden where no one will ever see them.

 

 

Turn the front to the back, cut up the back, and add in more stuff and people will never know.

 

 

Yeah this doesn't look anything like the turret I mocked up last update, and even less like the paper model I made at the start.

[djizomdjinn]

Trunnions mocked up, gun put in final position, gun depression measured. "Only" 22 degrees of gun depression. (For reference, the Abrams gets around 10, and a T-72 around 6.) Had to put a notch in the front of the turret for that, but it's not like the armor there's protecting much. Even if it was, it's worth another two or three degrees.

 

 

Modern tanks have a lot more crud sticking off of them, so if I really want to push my scratchbuilding skills I'll have to learn to do the fine details. Sensors, from left to right: the gun muzzle reference sensor, the commander's independent sight, and the main gun sight.

 

 

Blowout panels for the ammunition contained in the bustle. Oddly, since the gun is offset, the shot lockers are different sizes as well in order to have the autoloader right behind the gun.

 

 

Ivan Scaleov is back, modeling my new troop compartment. The floor is treadplated. The brackets on the floor I envision being the tracks for a sort of roller system for the power pack; disconnect and remove the cooling system above, unbolt the back wall, unbolt the engine from everything, and then theoretically it just slides out the back on rollers. This means, of course, that not much extra gear can be placed on racks inside the troop compartment; they'd have to be on the back wall of the vehicle in order to not block the engine from coming out when it needs replacing.

[Chaoswolf]

I like the 'realism' that you are incorporating into each of your builds.

[djizomdjinn]

Short update, because I ended up undoing some of the work I got done.

 

 

Made a commander's cupola, put it on, tried to make it look nice via Apoxie Sculpt, ended up tearing it off. Inspiration was taken from the AMX-13. but what works for a light tank doesn't for a main battle tank. Namely, it's impossible to put any solid amount of armor on there, and it juts out and becomes a ridiculously inviting target. In fact, the sloping armor of the Walker Bulldog isn't giving me any room to work with at all. So I'm re-profiling the front. Still haven't decided if I'm going to go conventional top hatch, or be a bit strange and put side-rear hatches in the turret. After all, if you're already expecting to be fighting defensively with this tank in the mountains, and you expect to lose the air war, maybe you'd put the hatches on the side and rear instead of on the top?

 

 

You'll notice that one gun trunnion has been installed, while the second has not. By taking the barrel off, I can actually take the gun off right now, which means I can work on the turret without finishing the gun.

 

I know it's easy to make up stats for a plastic panzer, but that could be 1.2+ meters of armor on the turret face right there, if I went with back hatches. That's... slightly ludicrous. Anyways, in the end the turret ended up being about the size of the Leopard 1 turret after all. You can only do so much I guess.

 

Ugh, need some fresh air. Apoxie Sculpt is cheap and useful, but the smell...

[djizomdjinn]

Unfortunately it seems I'll be quite busy for the next few months, so stuff like this won't get anywhere the amount of time and attention as they used to for a while. But, hey, one more update before it turns into a trickle.

 

 

Been playing around with the idea of a self-entrenching dozer blade that folds under and becomes part of the lower armor plate, ala Strv 103. I mean, if the tank is designed to fight purely from a defensive posture, it makes sense to give it the ability to create it's own defensive positions, right...? On the other hand it's more front weight on an already very front-heavy vehicle, and visually it looks kind of funny as well. Maybe I'll save it for the add-on package.

 

 

Also been playing around with the idea of upgunning the tank to 120mm. If this is a 1980s tank and not a 1960s one, complete with independent thermal viewers and other fancy electronic bits, it'd make sense to have an upgraded gun as well. After all, the 105mm L7 dates to the mid-50s.