Looking at the schematics of the
the Pz-IB, the 'consumption' of the protected volume by the propulsion group seems excessive. The Vickers Mk.V light tank , while having the similar motorization, was a lot shorter affair, also lighter, with space for 3 men crew (vs. just 2 on the Pz-I). Perhaps relocating the engine aside the gearbox (and opposite to the driver) would've freed a lot of space.
The Pz-Ib was a bodge job. They had screwed up sticking an underpowered flat 4 engine of 3.5 liters (air cooled) into a 5 ton tank and it was not working. The Ib was an attempt to solve the problem with minimal retooling. Stretch the hull, put in inline 6 in place of the flat 4 opposed engine and mount an extra road wheel to carry the extra weight (which wasn't all that much) and size. They made fewer Ib's than they did Ia's. They used the same engine that was in the 1 ton half-track.
They could have done better but why? Production ended in 1937 for all practical purposes.
There were two later "versions" that were total wastes of time, resources. A side from general size they had nothing in common with the Pz Ib.
They were ordered in late 1939 but due to other things having "priority" they were not built (or completed) until the middle of 1942. They were bad ideas in the Fall of 1939, proved to be bad ideas in the BoF in 1940 and may only have been built to keep cash flow going to the companies. They were useless in 1942.
8 tons 30mm armor on the front, 20mm sides and rear, still a 2 man crew. A high revving 4.7liter engine and 8 forward gears and 2 in reverse (or a 4 speed with a 2 speed?)
The gun was a odd ball firing the same 7.9mm ammo as the German AT rifles. Whatever use it had in 1939/40 was long gone in 1942 and there was no HE ammo (I am sure this time)
40 built. It was fast and it was fast and it was.............................fast.
The other was worse.
Somebody saw a British photo of a Maltida I and said "we got to have something even stupider!!!"
So they labored mightily for over 2 years and produced something that was even dumber than the Maltida I.
At least the Matilda I was cheap.
This thing was twice as heavy (24 short tons, 80mm armor on the front), used an engine of nearly twice the power and went twice as fast (A blistering 25kph, on a road)
Twin MG34s may have been better than the MG 13s in the Pz I but wither they were much better than a Vickers gun is subject to question.
30 built or at least partially. Turrets may have been used in some fortifications?
What is truly astonishing is that each of these had a further development prototype built or building.
The Pz II
was an improved Pz I
British were testing this in 1938.
But it didn't really enter production until the summer of 1940.
You need a heck of an improvement to get a Pz II up this level in 1940-41 or even up to the level of a Soviet T-26 mod 39.
Engineering time should have been going into better/improved Pz III & IV tanks (or new 24-28 ton tank)