Sd.Kfz. 251

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. 11 vehicle. The larger of the pair (the Sd.Kfz. 250 being the lighter one) 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 over 15,252 vehicles and variants produced by various manufacturers, and were commonly referred to simply as "Hanomags" by both German and Allied soldiers.

Design
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 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.

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 of an open top 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's 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-1940, featured a simplified hexagonal-shaped forward armoured 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 ground pressure and provided better traction, giving the Sd.Kfz.251 better cross country performance than most other nations' half-tracked vehicles. However, the interleaved and overlapping main road wheels shared a major problem with the Tiger I and Panther main battle 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.

Use
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.

Variants


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.


 * Sd.Kfz. 251/1 - Schützenpanzerwagen. Standard personnel carrier.
 * 251/1 I - As above, but 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 detection equipment, to be used in combination with Sd.Kfz. 251/20 Uhu. Mostly Ausf. D variants.
 * Sd.Kfz. 251/2 - Schützenpanzerwagen (Granatwerfer). 81 mm Mortar carrier. Carried 66 rounds for the GrW34. A base plate was also stored so the mortar could be offloaded and used.
 * Sd.Kfz. 251/3 - 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
 * Sd.Kfz. 251/4 - Schützenpanzerwagen für Munition und Zubehör des leIG18. Gun-towing tractor, initially for use with the 7.5 cm leichtes Infanteriegeschütz 18. Later used to tow the 50 mm Pak 38, 75 mm PaK 40 and 10.5 cm leFH 18 Light Field Howitzer.
 * Sd.Kfz. 251/5 - 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 in versions Ausf. A and Ausf. B.
 * Sd.Kfz. 251/7 I - Pionierpanzerwagen. Another assault engineer vehicle with fittings to carry assault bridge ramps on the sides.
 * 251/7 II - As above but with different radio.
 * Sd.Kfz. 251/8 I - Krankenpanzerwagen. Armoured ambulance capable of carrying up to 8 seated casualties or 4 seated casualties and 2 stetcher cases.
 * 251/8 II - As above but fitted with FuG5 radio and 2m rod antenna. Assigned to HQ and Panzer units.
 * Sd.Kfz. 251/9 - 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 gun mount was also used to create the Sd.Kfz. 250/8 variant.
 * Sd.Kfz. 251/10 - 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.
 * Sd.Kfz. 251/11 - Fernsprechpanzerwagen. Telephone line layer.
 * Sd.Kfz. 251/12 - Messtrupp und Gerätpanzerwagen. Survey and instrument carrier for artillery units.
 * Sd.Kfz. 251/13 - Schallaufnahmepanzerwagen. Sound recording carrier for artillery units.
 * Sd.Kfz. 251/14 - Schallaufnahmepanzerwagen. Sound recording carrier for artillery units.
 * Sd.Kfz. 251/15 - Lichtauswertepanzerwagen. Flash spotting carrier for artillery units.
 * Sd.Kfz. 251/16 - Flammpanzerwagen. 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.
 * Sd.Kfz. 251/17 - Schützenpanzerwagen (2 cm). Anti-aircraft vehicle armed with a 2 cm KwK38 on a pedestal mounting with a small armoured 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 - Beobachtungspanzerwagen. 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.
 * Sd.Kfz. 251/21 - Schützenpanzerwagen (Drilling MG151s). Anti-aircraft 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.
 * Sd.Kfz. 251/22 - 7.5 cm PaK40 L/46 auf Mittlerer Schützenpanzerwagen. Fitted with a 75 mm PaK 40 anti-tank gun.
 * Sd.Kfz. 251/23 - 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 armoured car.
 * OT-810 - Czechoslovakian produced version, made by Praga and Tatra. 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. 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 2 were made in this way judging by their number plates.