the Kettenkrad semi-tracked motorcycle converted into a remote-controlled demolition vehicle, source: Flickr.com with the permission of the publishing user, edited

Mines and their clearance

Among the weapons deployed on an unprecedented scale during the Second World War, land mines certainly rank high. Tens of millions of mines of all types were used throughout the conflict, particularly in Africa and Russia, but also along the coastal regions of Western Europe. Clearing minefields has traditionally been the domain of combat engineers, and the Second World War was no exception. Mine clearance is an extraordinarily dangerous activity in its own right. When one adds the fact that it frequently had to be carried out under enemy fire, it comes as no surprise that engineers have always sought technical means to make their task as safe as possible — and the word "always" is not much of an exaggeration, as demonstrated by THIS undated historical illustration showing that technical aids for safer disposal work were in use a very long time ago indeed.

Quality at a reasonable price

It was precisely for this purpose that the firm of Borgward developed, in 1940, two successive variants of a remote-controlled minefield-clearing vehicle, designated Minenräumwagen B I and Minenräumwagen B II. These were single-use vehicles, since the destruction of mines — or any other target — meant the destruction of the vehicle itself. Great emphasis was therefore placed on keeping the purchase price as low as possible during both development and production. When it came to the resulting value for money, however, neither of the Borgward Minenräumwagen vehicles met the customer's expectations. Sometime around mid-1941, the idea therefore emerged of building a different but similar vehicle that would offer a higher quality of construction at a still reasonable price. This was to be achieved by using the proven, mass-produced semi-tracked motorcycle kleines Kettenkraftrad HK 101 (Sd.Kfz. 2), known simply as the Kettenkrad.

as poor in quality as it is rare — a photograph of the first prototype of the remote-controlled Kettenkrad, with the driver's position moved all the way to the rear, source: Flickr.com with the permission of the publishing user, edited

First version

The task of converting the motorcycle into a remote-controlled charge carrier was naturally entrusted to its manufacturer, Neckarsulm Strickmaschinen Union (NSU). The first prototype was completed sometime in the autumn of 1941. The driver's position was moved to the rear of the vehicle, and the space in front of it was used to house the explosive charge and the remote-control mechanisms. Little information is available about this first prototype, and the same applies to photographs of it. The army was apparently not particularly satisfied with it, as in spring 1942 it commissioned NSU to develop a new version. It can be assumed that even the relocation of the driver's position to the rear of the vehicle alone represented a considerable increase in production costs, and the army therefore demanded as few departures from the standard series Kettenkrad as possible.

Second version

The second version of the remote-controlled vehicle therefore resembled the standard semi-tracked motorcycle much more closely. The driver's position with its characteristic handlebars remained at the front, while in place of the original rear seat a new cover panel appeared, concealing the control system and — most importantly — the large explosive charge. The wireless remote-control system was taken from the heavy Sprengladungsträger B IV, though it was stripped of certain functions, such as the command to jettison the charge. On the modified Kettenkrad, the charge was an inseparable part of the vehicle, meaning the entire machine was destroyed along with it when detonated.

Tactics and deployment

During normal movement of the remote-controlled Kettenkrad, the driver simply sat at the handlebars and drove it like an ordinary production motorcycle. Once he reached the assembly area for the attack, he turned the vehicle so that its rear faced the intended target and switched control from direct to remote mode. The front wheel fork was then locked in the straight-ahead position using metal braces. From that point, the vehicle was guided to its target by remote control, travelling in reverse — backing towards the objective. The demolition vehicle in question was apparently designated kleines Kettenkraftrad (f.g.), where the letters f.g. stood for funk gelenkt, meaning radio-controlled.

Kettenkrad (f.g.) during its trial deployment in Crimea as part of Panzer Abteilung 300 (FL), source: Flickr.com with the permission of the publishing user, edited

At least four of these remote-controlled Kettenkrads were deployed at Sevastopol in June 1942, operating as part of the special unit Panzer Abteilung 300 (FL). The results of the deployment were far from satisfactory. The 1.5-tonne vehicle had a centre of gravity that was far too high for reliable remote control. When a driver is seated directly in the vehicle, he can see exactly where he is going and instantly feels the vehicle's tilt and behaviour — this is an entirely different matter from guiding it by remote control from a distance of perhaps 1,500 metres, hidden in a trench or behind vegetation. In short, the remote-controlled "motorcycle" tipped over far too often. The project was therefore judged a failure, but it simultaneously confirmed that the Kettenkrad's chassis was at least suitable as the basis for a vehicle of this type. This in turn laid the groundwork for the development and production of the more advanced demolition vehicle, the Springer.

ARTICLE
CONTENTS:

A BIT OF HISTORY

QUALITY AT A PRICE

FIRST VERSION

SECOND VERSION

TACTICS AND DEPLOYMENT