German Empire (1906) SPAAG – 1 Prototype

The beginning of the twentieth century saw the emergence of the first armored car designs. The first vehicles were partially armored, like the British Simms’ War Car and the French Charron, Girardot & Voigt (CGV) of 1902. Fully enclosed vehicles started to appear in 1905, like the armored car from CGV and the Austrian Austro-Daimler Panzerautomobil. Inspired by these vehicles, German engineer Heinrich Ehrhardt started to develop an armored car as well, but he had a new idea in mind; exploiting it as an anti-air vehicle.



Contemporary artist impression of the Ehrhardt BAK acting as infantry support during an attack. Source: Rotterdamsch Nieuwsblad

Heinrich Ehrhardt

Heinrich Ehrhardt was a German entrepreneur and industrialist. He was born in 1840 in the town of Zella-St. Blasius (Zella-Mehlis). Ehrhardt founded several factories, including the well-known Rheinmetall factory in 1889, located in Düsseldorf, as well as several car factories. In 1903, he founded the Gustav Ehrhardt Automobile AG in his hometown, which started producing both civilian and military trucks. From 1906 onwards, the factory started to produce trucks for the military only. During the First World War, these factories played quite a big role in the German war effort, with their most famous vehicle probably being the Ehrhardt E-V/4 armored car. Ehrhardt died in 1928, at the age of 88.

The Balloon and its Opposition

The development of the Ehrhardt BAK is not only connected to the development of armored cars in the early 20th century, but is also related to the development of military aircraft, especially balloons, during the same period. The 19th century saw the rise of a new weapon, the balloon. Its potential strategic and tactical use for military operations, like observing the battlefield, was well-recognized, especially in Germany, the home of Zeppelin. However, a new weapon also required a new weapon to fight it.

Development

Already in 1905, Ehrhardt experimented with the idea of an anti-air gun on a car chassis, when he mounted a small-caliber gun on an Ehrhardt-Décauville 16/20 PS chassis. Although the pivot design was inspired by anti-air guns made by Friedrich Krupp since the Franco-Prussian war from 1871, the elevation system and the gun itself were made by Rheinmetall, the company founded by Heinrich Ehrhardt.



The Ehrhardt-Décauville from 1905, equipped with a Rheinmetall gun. Source: Stanislav Kirilec

During 1906, Ehrhardt designed and built the Ehrhardt BAK. It was ready in time to be presented at the VII. Automobil Ausstellung (Car Exhibition) in Berlin at the end of 1906. It was the biggest car exhibition in Germany at the time and was also visited by the German Emperor Wilhelm II. He also inspected the Ehrhardt. It was the second time an armored car was exhibited at the show, as Opel already presented their Kriegswagen during the previous exhibition in early 1906.

Name

Like many early armored vehicles, the Ehrhardt BAK does not have an ‘official’ name. The most common designation: Ehrhardt Ballon Abwehr Kanone (Anti Balloon Gun), BAK for short, is also used in this article, but the vehicle often goes under different names like Panzerautomobil (armored car), Panzerkraftwagen (armored truck), Ballon Verfolgungsfahrzeug (balloon suppression vehicle), or Ballonabwehr Automobil (anti balloon car). Essentially, these different names are all descriptions of what the vehicle really is, an armored self-propelled anti-air gun, the very first of its kind ever produced.



The Ehrhardt being inspected by the German Emperor (x) at the VII. Car Exhibition in Berlin. Note the 5 cm shells standing on top of the engine compartment. Source: Public domain

Design

The Ehrhardt BAK was based upon a conventional chain driven light lorry, with rear wheel drive, the engine in the front, and driver compartment in the middle. The vehicle was protected by 3 mm thick armor all around and louvers were made on the front and sides of the engine for sufficient cooling. The armor thickness was criticized by military experts as they rightfully noted that the armor was too thin to stop enemy fire, and so it was only an unnecessary ballast and waste of precious resources.

The driver’s compartment offered space for the driver on the right and a commander on the left side. Both had one vision slot facing forwards and the complete front armor plate could be folded upwards for better vision but should be closed in case of direct combat. Doors were installed on both sides of the vehicle.

Although no official documentation is known about the color of the vehicle, a visitor of the Exhibition in Berlin notes in a Dutch newspaper that the armored car was grey. On pictures of the Exhibition, the Ehrhardt seems to be painted in a light color which suggests a lighter shade of grey.



A retouched image showing the vehicle with a half-opened front plate and gun in lowest depression of 5 degrees. Source: Contemporary newspaper