Panzerkampfwagen I Ausf.A ohne Aufbau
Panzerkampfwagen I Ausf A
Originally known as MG Panzerwagen (V Kfz 617) and given the Sonderkraftfahrzeug designation Sd.Kfz.101, the Ausf A was armed with two machine guns in a small turret. The 450 production tanks saw service from 1934 to 1941, last seeing action in Finland.
Pz.Kpfw I Ausf A with Krupp M601 engine
Panzerkampfwagen I Ausf B
After initial service the Ausf A was found to be underpowered and the engine prone to overheating. A more powerful engine was fitted and the superstructure transferred to the longer chassis of the kl Pz Bef Wg to produce the Ausf B, a.k.a. LaS Maybach, seeing service from 1935-1943, latterly as a command tank.
Pz.Kpfw I Ausf B with Krupp M601 engine
Panzerkampfwagen I Ausf C
The Ausf C light tracked reconnaissance vehicle, a.k.a. PzKpfW I nA or VK601, was a comprehensive re-design of the Pz I, with little commonality with earlier Ausfuhrungen introducing the Schachtellaufwerk (inter-leaved track wheels) used in many later Panzers. Forty Ausf C were built, two being sent to the Eastern Front for evaluation, the remainder were in action during the Normandy invasion of 1944. 
Panzerkampfwagen I Ausf F VK1801
The Ausf F heavily armoured infantry assault tank (MG armed), a.k.a. PzKpfW I nA verstärkt or VK1801, was an up-armoured Pz I with the Schachtellaufwerk (inter-leaved track wheels) of the Ausf C, and a turret mounting two machine-guns. Thirty Ausf F tanks were built between April and December 1942, eight of which were sent to the Eastern Front for evaluation.
Special Purpose Vehicles
Panzerkampfwagen I Ausf A ohne Aufbau
The first Panzer I vehicles to be built, 15 of this variant were completed by various firms (Daimler-Benz, Henschel, Krupp, MAN, and Rheinmetall) in a program intended to develop industrial capacity and provide initial training vehicles to the Wehrmacht. The Ausf A ohne Aufbau was a Panzer I hull without any superstructure or turret. The interior was completely open. The vehicle was crewed by a student driver and instructor, with room for three student observers behind them. The suspension and hull were identical to the Ausf A, but total weight was reduced to 3.5 tons and height to 1.15 m. Performance was similar.
Munitionsschlepper auf Panzerkampfwagen I Ausf A
Munitionsschlepper I Ausf A (Sd.Kfz.111) - light ammunition carrier,
Munitionsschlepper I Ausf A/B - cargo/ammunition carrier,
Flammenwerfer auf Panzerkampfwagen I Ausf A
A simple field modification, the Flammenwerfer had a portable flamethrower with enough fuel for about 10 seconds of firing at a range of up to 25 m mounted in place of one of the machine guns. The idea came from an experiment during the Spanish Civil War, and was intended to give the Panzer I more firepower against close targets. The conversion was not permanent, and was only reported to be used in the Battle of Tobruk by the German 5th Light Division.
Kleiner Panzerbefehlswagen (kl Pz Bef Wg) Sd.Kfz.265 - light command tank,
Main article: SdKfz 265 Panzerbefehlswagen
Given the designation SdKfz 265, the kl Pz Bef Wg was a modification of the Ausf A designed to provide a command vehicle for Panzer units. This required lengthening the chassis (by adding a fifth road wheel) and upgrading the engine. Ultimately, this chassis would be the basis for the improved Ausf B version. The klPzBefWg had a built-up superstructure in place of the turret, affording more interior room for command equipment and a FuG6 radio in addition to the FuG2. A single MG13 or MG34 in a ball mount on the front of the superstructure was provided, although often removed. Slightly heavier (5.9 tons) and taller (1.99 m) than the Ausf B, the klPzBefWg served with all Panzer units into the early war years. It received an additional 15 mm of armor later, and was moved to auxiliary duties by 1942. 184 were built by Daimler-Benz at the same time as Ausf B production, and six examples were built from Ausf A tanks.
Panzerkampfwagen I Ausf B ohne Aufbau
The Ausf B ohne Aufbau used the same chassis as the Ausf B, but omitted the superstructure and turret. Designed to provide Panzer units with a tracked recovery and repair vehicle, 164 were produced alongside the standard Ausf B vehicles. However, the introduction of larger tanks meant it was unable to do recovery work, and by 1940 it was being transferred to training duties. Compared to the Ausf B, it was much lighter (4.0 tons) and shorter (1.35 m). Like the Ausf A ohne Aufbau, the compartment was open-topped; the hull was armored.
Panzerjager I - 37mm Pak gun carrier
4.7 cm PaK (t) (Sf) auf Panzerkampfwagen I Ausf B
Main article: Panzerjäger I
Commonly known as the Panzerjäger I, this version marked Germany's first attempt at an armored tank destroyer. The turret was removed and a 4.7 cm PaK (t) antitank gun (captured from Czechoslovakia) with a tall wrap-around gun shield was installed. Made from 14.5 mm thick armor plate, the shield offered no protection to the rear or above. The gun was capable of 35° of traverse and elevation from −8° to +12°. 86 rounds were carried for the main gun. While performance was similar to the Ausf B, it was heavier at 6.4 tons and taller, 2.25 m, than the B.
Panzerjäger IB mit 7.5cm StuK 40 L/48
Sturmpanzer I Bison (Sd.Kfz.101) - 150mm sIG 33 gun carrier,
15 cm sIG 33 (Sf) auf Panzerkampfwagen I Ausf B
Main article: 15 cm sIG 33 (Sf) auf Panzerkampfwagen I Ausf B
This vehicle was sometimes known as the Bison. The larger Ausf B chassis made possible the mounting of heavier guns with removal of the turret. The largest was the 150 mm heavy infantry gun, the sIG 33. This mammoth piece was relatively short and barely fit inside a tall superstructure that was constructed up to the vehicle's 2.8 m height and over the tracks to their full 2.06 m width. The superstructure armor was light—only 13 mm—and only protected the front and sides. The heavy resulting weight of 8.5 tons overstressed the chassis; the vehicle was not a great success. 38 were converted from Ausf B tanks in February 1940. They served with six heavy SP infantry gun companies, with survivors in service into 1943. The sIG mounting was capable of 25 ° of traverse and 75 ° of elevation, and could be depressed to −4 °. It used a Rblf36 sight. Ammunition was carried separately, there being no room for onboard shell storage. The sIG would be mounted more successfully on larger chassis as the war progressed.
15cm sIG33(Sf) auf PzKpfw I Ausf B Sturmpanzer I Bison 150mm sIG 33 gun carrier Sd.Kfz.101
Flammenwerfer auf Panzerkampfwagen I Ausf. A or Flammpanzer I
A field modification, similar to that done to the Ausf B earlier in Spain, developed in preparation for the assault on Tobruk, by the 5th le division (5th Light Division) field engineers of the Deutsche Afrika Korps, and issued to the 5th Tank Regiment. the flamethrower was capable of 10 - 12 one second bursts up to 25 m (82 ft).
Flammenwerfer auf Panzerkampfwagen I Ausf B
An experimental field modification similar to that done to the Ausf A later in North Africa, this conversion was made during the Spanish Civil War. There is no record of later use during World War II.
Explosive Charge Layers
Ladungsleger auf Panzerkampfwagen I Ausf B / Abwurfvorrichtung auf Panzerkampfwagen I Ausf B
A field modification kit, the ''Ladungsleger (the prototype) or Abwurfvorrichtung (the “production” version), explosives layer, was mounted on the rear deck of an Ausf B tank and used to lay explosives to defeat field fortifications. A number of vehicles were given these kits, with authorized use on the armoured engineers company of each Pioneer Battalion.
Ladungs1eger 1 auf PzKpfw I Ausf B ver 1(zerstorerpanzer) - explosive charge layer
Ladungs1eger 1 auf PzKpfw I Ausf B ver 2(zerstorerpanzer) explosive charge layer
Ladungsleger auf PzKpfw I Ausf A/B (zerstorerpanzer) explosive charge layer
Self-Propelled Anti-aircraft Guns
Flakpanzer I Ausf A (Sd.Kfz.101) Flak 38
Main article: Flakpanzer I
A rare modification that attempted to make the Panzer I into a self-propelled anti-aircraft gun was the Flakpanzer I that was not produced widely due to limited operational utility.
Pz I B 15mm Drilling
Engineer Armored Vehicles
Pionier-Kampfwagen I - engineer tank,
Mine Clearing Equipment
Minenraumer I Ausf B - mine clearing vehicle (50 produced in 1938)
Tank Recovery Vehicles
Leichte Bergepanzer I - light recovery vehicle
Fahreschulewagen / Schulfahrzeuge I - training tank
Instandsetzungstrupp I - troop carrier / recovery vehicle,
Sanitatskraftwagen I (Sd.Kfz.265) - armoured ambulance,
Pz Kpfw I Attrappe
Krupp L.K.A.II Light Tank (Pz.Kpfw II Prototype
Pz.Kpfwl Ausf.A 'Modificado', iliPz.Kpfwl Ausf.A "Breda" (with 20-mm model 1935 gun)