This is actually a light tank inside a larger, heavily compartmentalized flotation hull. Yes, I know I just said HEAT is out until 1940, but when it comes they'll soon find out that pre-detonation renders it ineffective even against this little armor.
It has been made to be upgradeable - the 45mm/L66 is just the starting gun, the turret ring is large enough to accommodate turrets with capacity up to a long 75mm (such as the German
7.5 cm KwK 40 L/48) or our own ATHM1933 87.6mm/L29 Howitzer; with proper turret design it can even include a radar 40mm or twin 20mm autocannon AA configuration (targeting radar not available until 1940). However, building SPG or TD casemates on this design is inadvisable due to the excessive weight.
It can also receive 20mm of additional armor in the front, 15mm on the sides, 10mm on the stern and 5mm elsewhere...
However, its engine is also rather weak, and if the tank's weight is increased, a more powerful engine must absolutely be fitted (requires a new engine design to fit). The estimated maximum configuration would appreciate an upgrade to 350-400hp and it'd require an attachable bow plate to keep it from plowing into the water.
This tank's broad tracks allow it to operate in any soggy or wet terrain short of an actual quicksand pit (where it'll get bogged, but not sink).
Weight: 18.5t (max displacement 24t)
Length: 6.05m
Width: 3m
Height:
2m hull
0.40m starting turret
Ground clearance: 0.4m
Crew: 4 (Commander/radio operator, Driver, Gunner, Loader)
Armour:
35mm@60º + 10mm front (max 55mm + 15mm )
25mm@30-45º + 5mm sides (max 40mm + 10mm )
15mm + 5mm rear (max 25mm + 10mm )
20mm top and bottom (max 25mm)
Main armament: C-V-45-M1935 45mm/L66
requires new turrets to upgrade up to 75mm/L48 AT gun (TBD)
or ATHM1933 87.6mm/L29 Howitzer
or radar (TBD, IRL 1940) AA, sporting a single 40mm or twin 20mm autocannon AA.
Secondary armament:
Coax 12.7x108mm HMG (TBD)
Pintle 7.62x54mmR MMG or twin MMG (TBD)
Engine: 200 hp (max 400hp)
Suspension: Christie
Water propulsion: Sail drive
Operational range: 300km
Speed
road: 35km/h (throttled at 50Km/h)
off-road: 15km/h (throttled at 50Km/h)
water:5 Kn (9.2Km/h) (throttled at 10Kn, 18.4Km/h)
Note: I screwed up on the road wheels, they should be much larger and hollow, increasing flotation and dispensing with return rollers, but I just can't be made to redo the whole section.