The Sd.Kfz. 251 (Sonderkraftfahrzeug 251) half-track was an armored fighting vehicle designed and first built by the Hanomag company during World War II, and based on their earlier, unarmored Sd.Kfz. 11vehicle. The larger of the pair (the Sd.Kfz. 250 being the lighter one, designed and built by Demag) of the fully armored wartime half-tracks of the Wehrmacht, the Sd.Kfz. 251 was designed to transport the panzergrenadiers of the German mechanized infantry corps into battle. Sd.Kfz. 251s were the most widely produced German half-tracks of the war, with at least 15,252 vehicles and variants produced by various manufacturers, and were commonly referred to simply as "Hanomags" by both German and Allied soldiers.
There were four main model modifications (Ausführung A through D), which formed the basis for at least 22 variants. The initial idea was for a vehicle that could be used to transport a single squad of 10 panzergrenadiers to the battlefield protected from enemy small arms fire, and with some protection from artillery fire. In addition, the standard mounting of at least one MG 34 or MG 42 machine gun allowed the vehicle to provide support by fire for the infantry squad once they had disembarked in battle.
The armour plates were designed to stop penetration by standard rifle/heavy machine gun bullets (like the Mauser 7.9X57mm bullet) by using both metal thickness and armour sloping. The fairly vertical front-facing plates were 14.5mm thick; the sides were steeply angled, V-shape and just 8mm thick, saving weight. These plates were both safe against the normal (non-tungsten) rifle AP round, which could pierce about 8mm of vertical armour.
Positive aspects of the open top included greater situational awareness and faster egress by the infantry, as well as the ability to throw grenades and fire over the top of the fighting compartment as necessary while remaining under good horizontal cover. The downside was a major vulnerability to all types of plunging fire; this included indirect fire from mortars and field artillery, as well as depressed-trajectory small arms fire from higher elevated positions, lobbed hand grenades, even Molotov cocktails, and strafing by enemy aircraft.
The first two models were produced in small numbers from 1939. A and B models can be identified by the structure of the nose armor, which comprised two trapezoidal armor panels - the lower of which had a cooling hatch. The B model, which began production in 1940, eliminated the fighting compartment's side vision slits. The C model, which started production in mid-1942, featured a simplified hexagonal-shaped forward armored plate for the engine. Models A through C had rear doors that bulged out. The C model had a large production run, but was quite complex to build, involving many angled plates that gave reasonable protection from small arms fire. From early 1943, the D model was developed with the purpose of halving the number of angled body plates, simplifying the design and thus speeding up the production. D models can be easily recognized by their single piece sloping rear (with flat doors).
The standard personnel carrier version was equipped with a 7.92 mm MG 34 or MG 42 machine gun mounted at the front of the open compartment, above and behind the driver. A second machine gun could be mounted at the rear on an anti-aircraft mount.
Variants were produced for specialized purposes, including with anti-aircraft guns, light howitzers, anti-tank guns and mortars or even large unguided artillery rockets, as well as a version with an infrared search light used to spot potential targets for associated Panther tanks equipped with infrared detectors.
Another potentially good design feature of the Sd.Kfz.251 was the large track area, with the characteristic "slack track" design with no return rollers for the upper run of track, and the Schachtellaufwerk system of overlapping and interleaved main road wheels common to virtually all German halftracks of the period. This lowered the ground pressure and provided better traction, giving the Sd.Kfz.251 better cross country performance than most other nations' half-tracked vehicles. The 251 also had tank steering, whereby the normal steering wheel moved the front wheels, but after more turning of the steering wheel, the tracks are braked to cause turning, like on a tank. This is more complicated, but gives greater mobility than US halftracks. However, the interleaved and overlapping main road wheels shared a major problem with the Tiger Iand Panther tanks that also used such roadwheel configurations - in muddy or winter weather conditions, such as those during a rasputitsa mud season or the coldest Russian winter conditions, accumulated mud and snow could freeze solid between the road wheels, immobilizing the vehicle.
The early production models of this vehicle were issued to the 1st Panzer Division in 1939.
These vehicles were meant to enable panzergrenadiers to accompany panzers and provide infantry support as required. In practice, there were never enough of them to go around, and most panzergrenadier units had to make do with trucks for transport.
Sd.Kfz. 251/7 "Pionierpanzerwagen"
There were 23 official variants, and sundry unofficial variants. Each variant is identified by a suffix to the model number; however, there was some overlap in the variant numbers.
. Standard personnel carrier.
- Sd.Kfz. 251/1 Ausf. A Ungepanzerte. Made with plain steel 5mm plates instead of armour, to make up numbers due to slow initial 251 production. Around 350 made up to mid 1940.
- 251/1 I - with intercom facilities
- 251/1 II - Rocket launcher (called "Stuka zu Fuß" (Walking Stuka) or Wurfrahmen 40) equipped with six side mounted frames for launching 280 mm or 320 mm Wurfkoerper rockets.
- Sd.Kfz. 251/1 - Falke Infrared imaging equipment for driver and mg42, to be used in combination with Sd.Kfz. 251/20 Uhu. Mostly Ausf. D variants.
- Schützenpanzerwagen (Granatwerfer)
. 81 mm Mortar
carrier. Carried 66 rounds for the GrW34. A base plate was also stored so that the mortar could be offloaded and used.
- mittlere Kommandopanzerwagen (Funkpanzerwagen)
. Communications vehicle, fitted with extra radio equipment for command use in Ausf. C and Ausf. D versions.
- 251/3 I - FuG8 and FuG5 Radios
- 251/3 II - FuG8 and FuG5 Radios
- 251/3 III - FuG7 and FuG1 Radios
- 251/3 IV - FuG11 and FuG12 Radios (with 9 m telescopic mast); Command vehicle variant (Kommandowagen)
- 251/3 V - FuG11 Radio
- Schützenpanzerwagen für Pionierzug
. Assault Engineer vehicle with inflatable boats stored in the side storage lockers, and light dismantleable assault bridges stored inside through loss of a seat for more storage space. Early command vehicles for Pioneer platoons (Pionierzug
) were equipped with a 37 mm Pak 36
anti-tank gun mount.
Sd.Kfz. 251/6 - mittlere Funkpanzerwagen (Kommandopanzerwagen). Command version equipped with map boards, cipher and encoding machines, enigma. Probably only made in versions Ausf. A and Ausf. B. Replaced by the 251/3 IV command SPW.
Sd.Kfz. 251/7 I
. Another assault engineer vehicle; this had fittings to carry assault bridge ramps on the sides.
- 251/7 II - As above but with different radio.
Sd.Kfz. 251/8 I
. Armored ambulance capable of carrying up to 8 seated casualties or 4 seated casualties and 2 stretcher cases.
- 251/8 II - As above but fitted with FuG5 radio and 2m rod antenna. Assigned to HQ and Panzer units.
- Schützenpanzerwagen (7.5 cm KwK37)
. Equipped with a 75 mm L/24
low velocity gun, using the same pedestal gun mount employed on the StuG III
. Nicknamed "Stummel" ("stump"). In 1944, a revised modular gun mount was introduced to facilitate production that also incorporated a coaxial MG42
. This universal gun mount was also used to create the Sd.Kfz. 250/8
variant and the Sd.Kfz.234/3.
- Schützenpanzerwagen (3.7 cm PaK)
. Equipped with a 37 mm Pak 36
anti-tank gun mount. Issued to platoon leaders as a fire support vehicle. Early versions used the whole top half of a pak36 with full gunshield, but later ausf. C & D used a much smaller half-size gunshield so that the vehicle didn't advertise it's firepower, so it looked more like a regular 251/1
Sd.Kfz. 251/11 - Fernsprechpanzerwagen. Telephone line layer.
Sd.Kfz. 251/12 - Messtrupp und Gerätpanzerwagen. Survey and instrument carrier for artillery units. Never built.
Sd.Kfz. 251/13 - Schallaufnahmepanzerwagen. Sound recording carrier for artillery units. Never built.
Sd.Kfz. 251/14 - Schallaufnahmepanzerwagen. Sound recording carrier for artillery units. Never built.
Sd.Kfz. 251/15 - Lichtauswertepanzerwagen. Flash spotting carrier for artillery units. Never built.
. Fitted with two flame projectors
and initially a rear mounted flamethrower
, detachable but still connected to the vehicle, to be operated by dismounted infantry. This was in addition to the standard forward machine gun mount. Six Sd.Kfz. 251/16 Flammpanzerwagens were authorised for issue to each Panzergrenadier
regiment or in the Pioneer battalion. Though vulnerable, they were used very successfully at night to quickly attack enemy infantry who had just captured German trenches, hitting the enemy before they could consolidate and bring up the heavy weapons that would make them much costlier to defeat later. Late ausf. D versions had larger gunshields.
- Schützenpanzerwagen (2 cm)
. Anti-aircraft vehicle armed with a 2 cm KwK38
on a pedestal mounting with a small armored turret to protect the gunner. Late war, it was issued as a platoon commander's vehicle to replace the Sd.Kfz. 251/10.
Sd.Kfz. 251/18 I
. Artillery observation vehicle.
- 251/18 Ia - Differences unknown, likely different radio fit.
- 251/18 II - Armored observation vehicle.
- 251/18 IIa - Different radio.
Sd.Kfz. 251/19 - Fernsprechbetriebspanzerwagen. Telephone exchange vehicle.
Sd.Kfz. 251/20 - Schützenpanzerwagen (Infrarotscheinwerfer) Introduced in late 1944, it mounted a 60 cm infrared searchlight with a range of 1.5 km for illuminating targets at night. Known as "Uhu" (Eagle Owl), they guided IR sight-equipped Panther tanks to targets that were out of range of their own smaller infrared searchlights.
- Schützenpanzerwagen (Drilling MG151s)
. Anti-aircraft and ground support variant equipped with a triple-mount ("Drilling" in German means "triple") of MG151
autocannon; early version being MG151/15 mm cannon, later being MG151/20 mm Luftwaffe cannon, on a Kriegsmarine triple mount. Awesome firepower, especially when organised into platoons of 6 SPW. But with each gun capable of firing 600+ rounds/minute, 3guns = 2000rpm, it could fire off its full load of 3000 rounds in just 90 seconds.
- 7.5 cm PaK40 L/46 auf Mittlerer Schützenpanzerwagen
. Fitted with a 75 mm PaK 40
anti-tank gun. Probably too big a gun for the carriage, overloaded but effective, and the Yugoslav military was still using captured examples into the 1950s.
- 2 cm Hängelafette 38 auf Mittlerer Schützenpanzerwagen
. Reconnaissance variant intended to replace the Sd.Kfz. 250/9
and fitted with the same turret mounting as the Sd.Kfz. 234/1
Probably never built.
produced version, made by Praga
. This version had an air cooled diesel engine, and an armored roof over the troop compartment. The vehicle was not liked by those who used it and was nicknamed "Hitler's revenge".
Field modified variants - Various field modified variants also existed during World War II. There was a kit for installing an armoured map table in place of the forward MG34 mount in use in 1941. One interesting variant was made at the closing stages of the war, when German forces removed the armored bodies of damaged Sd.Kfz. 251s and installed them on light truck chassis, resulting in a wheeled variant of the Sd.Kfz. 251. At least two were made in this way judging by their number plates.