N-L-M

Drummond is notable for being very bad at the technical side of design of armored vehicles, which contrasts strongly with how vocal he is with his opinions on the topic.

I for one look forwards to both of you sharing what you can, when you can.

To my knowledge, not in active service yet anywhere.
The more cynical amongst us would say that means it's still vaporware.

Looks more like a PG-7M warhead to me.

If.

For a very long time, converted tanks were the only infantry carriers in the IDF worth a damn. They were used extensively in Lebanon for the 20 years the IDF was parked there, for moving troops and for route clearance - very important against an opponent who very much liked IEDs. 
 

Cage armors short out the warheads of certain weapons (primarily, anything which functions like a PG-7 with its nose piezo fuze and twin conductive cones to the base detonator), and prevent detonation of the warhead.
Strykers, which are notoriously paper thin, have been running around with cage armor for the better part of 2 decades, as an example.

For a very long time, converted tanks were the only infantry carriers in the IDF worth a damn. They were used extensively in Lebanon for the 20 years the IDF was parked there, for moving troops and for route clearance - very important against an opponent who very much liked IEDs. 
 

Cage armors short out the warheads of certain weapons (primarily, anything which functions like a PG-7 with its nose piezo fuze and twin conductive cones to the base detonator), and prevent detonation of the warhead.
Strykers, which are notoriously paper thin, have been running around with cage armor for the better part of 2 decades, as an example.

Powerpacks weigh up to 5 or so tons, which I doubt that light crane can deal with, but conversely the 113 fitters can't deal with that either, so it's likely not a problem.
 
Replacing the 113 is always a good idea, even if it is by using an obsolete tank hull tortured almost beyond recognition.
 
Also, you aren't very subtle with your ban evading accounts, are you?

Powerpacks weigh up to 5 or so tons, which I doubt that light crane can deal with, but conversely the 113 fitters can't deal with that either, so it's likely not a problem.
 
Replacing the 113 is always a good idea, even if it is by using an obsolete tank hull tortured almost beyond recognition.
 
Also, you aren't very subtle with your ban evading accounts, are you?

Huh, when you own a website and are an administrator on the forum that you establish you can do anything you want

who knew? fucking sorcery

Final entry: Derebus-M
 

 
Main dimensions and statistics
 
Manufacturer: Paramount-Allen-Fullerton (Para-allful) Conglomerated
Mass estimate (as based on CAD model plus ~5830lb to account for drive systems, crew amenities, ammunition and miscellaneous components): 40.5t (36.8mt) fully loaded, fueled.
Armour mass (1-3.15" (25-80mm) RHA base plus ERA, composites, side skirts and engine bay liner): 21.5t (19.5mt)
Calculated mass: 41.9t (38mt)
Crew: 4 (commander, gunner, loader, driver)
Length: 246" (6.25m) hull, 261" (6.62m) total 
Width:  150" (3.8m) with skirt
Height: 86" (2.19m) to top of commander's hatch, 91" (2.30m) total
 

 
Firepower
 
Note: the armour used for the target has the same hardness (360BRN) as the armour used in the vehicle. The target was at 0 degree obliquity for calculation purposes.
 
Main gun: 102mm L/40 “4-inch 40 calibre” low-pressure gun:
“Low-pressure” = 310 MPa/3.45MJ
“Emergency” pressure = 345MPa/3.83MJ
Recoil stroke: 300mm
Vertical travel: +20/-10’
 
Ammunition:
23.9lb (10.85kg) HEAT-FS, penetration of around 16.9" (430mm) using 122mm BK13 derivative (337mm if using BK13 penetration), 2614fps (797m/s). 26.2lb (11.90kg) HE, 2.92kg fill, estimated blast penetration of ~1.4" (35mm) RHA, 2496fps (761m/s). Simple APFSDS (15:1 LD, 550BHN monosteel body, tungsten insert, 76mm cap, ring sabot): 1x15.2" (26x387mm) rod, 0.55/3.4" (14x86mm) insert, 3.4/1.9lb (1.53/0.84kg) penetrator/sabot mass, 1800m/s, 10.3/9"(261/228mm) penetration at 100/2000y. Uses emergency pressure.  
Case: 4x19.7" (102x500mm) steel case, 4.7" (120mm base), OAL (HEAT-FS) = ~28" (700mm) Charge weight: 4.9lb (~2.2kg) standard, 5.4lb (2.46kg) emergency Case weight: 11.5lb (5.2kg) Overall weight (HEAT-FS): 40lb (18.25kg)  
Note: if following the design of 3BM-26, this could be higher in practice. Using DeMarre the estimated penetration is 10.8" (274mm) at 2000y.
 
Storage:
21 rounds stored in an armoured storage bin in the turret. The bin exhausts through blow-off panels in the turret side and roof.
36 rounds stored in armoured bins on either side of the driver behind the fuel cells, with blow-off panels in the hull side and front
 
Secondary weapons: 
.30cal/7.62mm MG as coax
Both the commander and loader’s hatch rotate and have mounts for .30 cal MGs.
 
Fire control:
Single axis stabilized gunner’s sight (of the same configuration as Derebus).
Backup 60mm telescopic sight mounted to mantlet.
Duel axis stabilized main gun.
LRF (of the same configuration as Derebus) mounted above barrel.
 

 
Mobility
 
2xV6 liquid-cooled diesels, 19l displacement each: 290hp/ 216kW each, 553kg dry weight each.
Combined output to hydraulic torque converter, feeding into Merritt-Brown-style double differential system.
The engine, transmission and cooling system all sit in an aluminium tub that fits into a bay in the rear of the vehicle. This can be removed entirely for servicing, or to replace the powerpack with a different configuration.
Suspension: 20" (0.5m) ground clearance, geared torsion bar suspension, each axle pair in detachable units shrouded by aluminium housings. Wheels are 23.6" (0.6m) in diameter, with a track width of 27.6" (0.7m) and a pitch of 7.7" (0.195m).
PWR: 13.8 HP/t (11.4 kW/mt)
Fuel load: ~2550lb total (793lb/360kg in tanks flanking the driver, 1764lb/800kg in rear sponson tanks, range of 540mi at 30mph
Ground pressure (calculated MMP): 28.4 PSI (196 KPa). 
Track contact length: 153.5” (3.9m)
Track contact area: 58.8ft2 (5.46m2)
Nominal ground pressure (using calculated mass): 9.86 PSI (68KPa)
 


 
Protection
 
 
Notes:
Mounting bolts for ERA layers are not modelled, but are accounted for.
The covers over the rear fuel cells are 1" RHA.
 
Turret front:
Two layers of L-ERA, sloped at 75’
Base armour: 3.15" (80mm) RHA sloped at 75’
KE: 18.3" (465mm)
CE: 104" (2650mm) vs single-charge. Tandem charge rated to penetrate both layers via precursor is something like 17.9/12" (455/305mm), corresponding to 3"/3" high/low-precision charges and a 4" form factor.
 
Turret cheeks:
 
Note: because of how the cheeks are sloped, protection actually drops off the closer you get to the 25’ arc.
 
Three layers of L-ERA sloped at 25’ in the horizontal
Base armour: 3.15" (80mm RHA), sloped at 25’ in the horizontal
KE: 12" (305mm) from the front
CE: 56" (1425mm) (normal) vs single charge. Tandem charge rated to penetrate both layers via precursor is something like 12.2/7.3" (310/185mm), corresponding to 2.1/2.4" (55/60mm) high/low-precision charges and a 3" form factor.
 
Turret side armour array:
Two layers of L-ERA sloped at ~30’ in the horizontal
Base armour: 1" (25mm) RHA, sloped at ~30’ in the horizontal
KE: 5.9" (105mm) at 30’ from side.
CE: 13.4" (215mm) at 30' from side. Maximum angle that side can resist 7" CE is ~58' from the side (32' from the front).
 
 
Turret rear:
1.38" (35mm) RHA
 
Turret roof:
1" (25mm) RHA
 
Hull upper front:
Two layers of L-ERA, sloped at 75’
Base armour: 3.15" (80mm) RHA sloped at 75’
KE: 18.3" (465mm)
CE: 104" (2650mm) vs single-charge. Tandem charge rated to penetrate both layers via precursor is something like 17.9/12" (455/305mm), corresponding to 3"/3" high/low-precision charges and a 4" form factor.
 
Hull lower front:
Base armour: 5.15" (131mm) RHA sloped at 45’ from vertical
KE: 7.3" (185mm)
CE: 7.3" (185mm) vs single-charge.
Notes: the area next to the driver contains two fuel cells and two protected storage areas for ammunition. Hits here are correspondingly much more protected than the above would indicate, for both the upper and lower hull.
 
Hull side:
2 x L-ERA layers
25mm RHA skirt
1" (25mm) aluminium roadwheel (depending on hit location)
29.5" (750mm) air gap/fuel (depending on hit location)
Inner skin: 1" (25mm) RHA
KE: ~3.5" (85-95mm) (normal) / ~9" (210-245mm) (30’ arc from the front)
CE: ~4.2" (100-115mm) (normal) / ~32" (730-890) (30’ arc from the front)
Immunity zone against 15.7" KE: 21’ arc from front
Immunity zone against 7" CE: 56’ from front (34' from the side)
 
Notes: the upper hull side has numerous armoured brackets to hold the skirt. These would be expected to be hit when the impact is from the 30' arc, which would significantly improve protection.
 
Belly:
1" 25mm RHA
0-0.8" aluminium
 
Notes: the suspension units are aluminium boxes, the torsion bars are modelled as 2.75" (70mm) bars and each swing arm is attached to a hollow steel tube. The mine protection for the floor of the vehicle is accordingly expected to be much higher than these figures would indicate.
 


 

If.

If.

If.

Final Entry: Main Battle Tank, 2247, project name "Derebus"
 

 
Main dimensions and statistics
Manufacturer: Paramount-Allen-Fullerton (Para-allful) Conglomerated Mass estimate (as based on CAD model plus ~6600lb to account for drive systems, crew amenities, ammunition and miscellaneous components): 43.1t (39.1mt) fully loaded, fueled. Armour mass (1-2" (25-50mm) RHA base plus ERA, composites, side skirts and engine bay liner): 20.6t (18.5mt) Calculated mass: 43.4t (39.4mt) Crew: 4 (commander, gunner, loader, driver) Length: 246" (6.25m) hull, 379" (9.63m) total  Width:  150" (3.8m) with skirt Height: 95" (2.41m) to top of commander's hatch, 109" (2.77m) total  

Firepower

Note: the armour used for the target has the same hardness (360BRN) as the armour used in the vehicle. The target was at 0 degree obliquity for calculation purposes.
 
Main gun: 5-inch 55 calibre (127mm L/55) high/low pressure gun “High pressure” = 70000 PSI (480 MPa) operating pressure, 14.16MJ energy. Vertical travel: +15'/-10'  
Ammunition:
46lb (20.85kg) HEAT-FS, penetration of around 21" (535mm) using 122mm BK13 derivative (420mm if using BK13 penetration), 3074fps (937m/s), 9.14MJ using a low-pressure charge (~45k PSI). 46lb (23.2kg) HE, (5.7kg) fill, estimated blast penetration of ~55mm RHA, 2910fps (887m/s) Simple APFSDS (15:1 LD, 550BHN monosteel body, tungsten insert, 115mm cap, ring sabot): 1.57x23.54" (40x597mm) rod, 0.866x5.24" (22x133mm) insert, 14.2/5.2lb (5.6/3.2kg) penetrator/sabot mass, 1800m/s, 15.7/13.8" (400/350mm) penetration at 100/2000y.  
Note: if following the design of 3BM-26, this could be higher in practice. Using DeMarre the estimated penetration is 17.1" (435mm) at 2000y. Upgraded monobloc projectiles could match and eventually improve on this, up to 25.6" (650mm) before needing to rework the ammunition storage.
 
Details:
 
Gun has a high-pressure and low-pressure recoil option, selectable on the slide – this doesn’t affect the recoil mechanism, it just changes where the trip key is to unlock the breech. Warning: don’t fire high-pressure ammo with the low-pressure setting selected! Gun uses a separate 6.9x27" (175x685mm) charge: 44lb/20kg mass, semi-combustible case built along the lines of the 4Zh-40 charge used with the 2A26 gun), matching the length of the HEAT-FS round. This charge gives space to produce a more powerful round to match higher future barrel higher pressures (when using a secondary charge with the APFSDS projectile itself). 74000 PSI (510 MPa) gives a potential power of 15MJ. 94000PSI (650 MPa) gives a potential power of 19MJ. Final penetration potential of the gun with early monobloc DU projectiles is something in the region of 22" (550mm) at 2000y (putting it on par with Mango and Vant). Being able to store and handle a longer projectile (ie: above 27") would probably allow something a bit better than Snivets.  Low-pressure charges are shortened (17.1" / 435mm) and come with an ejection spring to work with the same tubes as the high-pressure charges.  
Storage:
19 charges and 9 active projectiles (HE and HEAT) in armoured tubes in the turret. The tubes are sealed at the front and lead to a blast chimney that outlets to blow-off panels in the turret roof. 10 inert projectiles (APFSDS) are stored in various places in the turret space, held by retaining clips. 16 charges and 8 active projectiles are stored on either side of the driver behind the fuel cells, also using the blast chimney approach (exhausting out the hull sides). 8 inert projectiles are stored in various spots in the hull.  
Secondary weapons: 
.30cal MG as coax Both the commander and loader’s hatch rotate and have mounts for .30 cal MGs.  
Fire control:
Single axis stabilized gunner’s sight Duel axis stabilized main gun Vertical coincidence rangefinder (stadiametric, 39.4" (1m) base) which doubles as a redundant back-up sight. Simple electronic gun-follows sight fire control system (encoder connected to sight mirror feeds elevation data into a transistor-based PID controller, which tries to match position on a similar encoder connected to the gun. When gun position and sight position align, the firing mechanism is electronically triggered). Semi-autoloader: the loader places the charge and warhead on trays in the bustle. these are then fed into the gun using an automatic mechanism (horizontal rammer, pivoting loading tray and rigid chain actuator to ram the warhead and charge home). The gun automatically returns to the loading position after each shot. A short spring at the end of the actuator helps to smooth out the loading impulse. LRF mounted above barrel.  
Note: Industrial espionage has allowed Texan engineers to copy the laser rangefinder proposed for use in the Cascadian M8A1 upgrade package. The Texan copy of the LRS-2 ruby laser rangefinder uses a flashlamp-pumped ruby laser, optical sensor, quartz timing circuit and the sequential event time sampling approach (with post-sampling amplification) to allow time-of-flight rangefinding using a lower timebase and bandwidth compatible with current electronics. Solid state electronic components allow the system to be fairly compact and robust. The rangefinder features a numerical readout in the gunner’s station. The rangefinder has a maximum operating range of 5km in clear conditions and has an average estimation error of 1%. 
 
The TBC-3A ballistic computer and IAPO-3 sight were not copied, as the high velocity of the APFSDS used in the 5”/55 cal main gun was felt to provide sufficient accuracy when paired with a good rangefinder.
 
Mobility

Transverse-mounted Kharkiv V-2-derived engine (specifically the V-55 diesel): 600HP/448kW, 2248lb/1020kg dry weight. The engine has been slightly re-bored to 40l, but is otherwise mechanically very similar to the engine used on the historical T-62. Hydraulic torque converter feeding into Merritt-Brown-style double differential system. An alternate engine layout would be two V-6 engines of similar total displacement, mounted normally, with a combined linkage to the torque converter. The engine, transmission and cooling system all sit in an aluminium tub that fits into a bay in the rear of the vehicle. This can be removed entirely for servicing, or to replace the powerpack with a different configuration. Suspension: 20" (0.5m) ground clearance, geared torsion bar suspension, each axle pair in detachable units shrouded by aluminium housings. Wheels are 23.6" (0.6m) in diameter, with a track width of 27.6" (0.7m) and a pitch of 7.7" (0.195m). Fuel load: ~2400lb total (639lb/290kg in tanks flanking the driver, 1764lb/800kg in rear sponson tanks, range of 490mi at 30mph PWR: 13.8 HP/t (11.4 kW/mt) Ground pressure (calculated MMP): 29.4 PSI (203 KPa).  Track contact length: 153.5" (3.9m) Track contact area: 58.8ft2 (5.46m2) Nominal ground pressure (based on calculated weight): 10.3 PSI (70.77 KPa)  
Protection


Notes:
Composite liner (50:50 HHA/textolite): density of 4.825g/cm3, layers of 0.2, 0.4, 0.6, 0.8 or 1" depending, with thickness adjusted to prefer the thickest possible layers (1"/1") with a thinner backing layer. Mounting bolts for ERA layers are not modelled, but are accounted for. The covers over the rear fuel cells are 1" RHA.  
Turret front:
Two layers of L-ERA, sloped at 75’ Base armour: 1" (25mm) RHA sloped at 75’ 2.1" (55mm) composite (25mm HHA, 25mm textolite), sloped at 75’ KE: 16.9" (430mm) CE: 89" (2250mm) vs single-charge. Tandem charge rated to penetrate both layers via precursor is something like 17.9/11.4" (455/290mm), corresponding to 3"/3" high/low-precision charges and a 4" form factor.  
Turret cheeks:
 
Note: because of how the cheeks are sloped, protection actually drops off the closer you get to the 25’ arc.
 
Three layers of L-ERA sloped at 25’ in the horizontal Base armour: 1" (25mm RHA), sloped at 25’ in the horizontal 2.2" (55mm) composite, sloped at 25’ in the horizontal KE: 11.4" (290mm) from the front CE: 55" (1400mm) (normal) vs single charge. Tandem charge rated to penetrate both layers via precursor is something like 12.2/7.3" (310/185mm), corresponding to 2.1/2.4" (55/60mm) high/low-precision charges and a 3" form factor.  
Turret side armour array:
Two layers of L-ERA sloped at ~30’ in the horizontal Base armour: 1" (25mm) RHA, sloped at ~30’ in the horizontal 1" (25mm) composite, sloped at 30’ in the horizontal KE: 5.9" (150mm) at 30’ from side. CE: 13.4" (340mm) at 30' from side. Maximum angle that side can resist 7" CE is ~20' from the side (70' from the front).  
 
Turret rear:
2" (50mm) RHA  
Turret roof:
1" (25mm) RHA  
Hull upper front:
Two layers of L-ERA, sloped at 75’ Base armour: 1" (25mm) RHA sloped at 75’ 2.2" (55mm) composite, sloped at 75’ KE: 16.9" (430mm) CE: 89" (2250mm) vs single-charge. Tandem charge rated to penetrate both layers via precursor is something like 17.9/11.4" (455/290mm), corresponding to 3" high/low-precision charges and a 4" form factor.  
Hull lower front:
Base armour: 1" (25mm) RHA sloped at 45’ from vertical 4.2" (106mm) composite, sloped at 45’ from vertical KE: 7.3" (185mm) CE: 7.5" (190mm) vs single-charge. Notes: the area next to the driver contains two fuel cells and two protected storage areas for ammunition. Hits here are correspondingly much more protected than the above would indicate, for both the upper and lower hull.
 
Hull side:
2 x L-ERA layers Composite skirt: 0.2" (5mm) HHA with a 0.8" (20mm) textolite backing 1" (25mm) aluminium roadwheel (depending on hit location) 29.5" (750mm) air gap/fuel (depending on hit location) Inner skin: 1" (25mm) RHA KE: ~3" (75-80mm) (normal) / ~8.2" (190-225mm) (30’ arc from the front) CE: ~3.8" (95-100mm) (normal) / ~30" (690-860) (30’ arc from the front) Immunity zone against 15.7" KE: 21’ arc from front Immunity zone against 7" CE: 54’ from front (36' from the side)  
Notes: the upper hull side has numerous armoured brackets to hold the skirt. These would be expected to be hit when the impact is from the 30' arc, which would significantly improve protection.
 
Belly:
1" 25mm RHA 0-0.8" aluminium  
Notes: the suspension units are aluminium boxes, the torsion bars are modelled as 2.75" (70mm) bars and each swing arm is attached to a hollow steel tube. The mine protection for the floor of the vehicle is accordingly expected to be much higher than these figures would indicate.

More photos and video. So far all vehicles fulfilled all requirements. What is left is climatic and EMC tests. Also interesting info about criteria for the final selection. 55% weight goes to the contract price. 30% to technical parameters and 15% to the offset offer. 
https://www.novinky.cz/domaci/clanek/strelba-i-jizda-tezkym-terenem-vyrobci-v-libave-predvadeli-sve-obrnence-za-miliardy-40361588
 

I've christened it "Derebus".
Armour package and hull/turret base altogether weigh 19.89t, putting me on track to hit my target weight of 41.3t.

Someone made a book about WWII bombing campaigns
 

 

 
Maybe I should try taking off with tailwinds next time...

Hello everyone!
 
I'd like you all to formally meet the FV601 Cossack, here in it's three configurations (from left to right): Heavy Armour, base configuration and FIBUA add-on kit.
 

MUH NERA

 
Birgus, (or Lynx, don't know yet the name) the Fulda Gap fever dream:
 

I think this is the farthest I've managed to get in a competition (by how many necessary components I've completed). 
 

 
She's up to 44.8 tons, but I know I can get that down... each individual wheel is 540 lbs, which seems high... the tracks are also about 2.5 tons each (dont know how heavy they're suppose to be).