Article written by Ray Mudway in February 1999.
The Kübelwagen :
Dr. Ing. (Doctor of Engineering) Ferdinand Porsche designed the V.W. KdF (Strength through Joy) people's car (known today as the "Beetle") but his son Dr. Ing. Ferry Porsche was in charge of the projects to re-design it for the German Army as the Kübelwagen & Schwimmwagen. The standard Kübelwagen was a great success but it wasn't totally suitable for all the conditions it encountered. Factory modifications such as the "DAK" (Deutsches Afrika Korps) & "Winterized" versions found favour in as much as many of the "theatre specific" modifications became standard series production elements ; this despite (or perhaps because of) the fact that the initial 500 "DAK" versions were sent to Russia & the winterized version ended up in North Africa ! (Interestingly, the Kübelwagen & Schwimmwagen were combined & redesigned as the Typ-597 "Jagdwagen" in 1955 for the new German Federal Army but it did not win the competition due to European politics.)
In Africa it was found that the Kübelwagen wasn't quite able to climb the soft sand dunes that had to be traversed and it would be handier if it could tow a small cargo trailer. By the first winter of the advance against Russia (1941/42), mainly in the Ukraine, the heavy mud and snows were proving that the Kübelwagen was not up to the job ; all wheeled vehicles became stuck in the snow and mud, despite of lots of technical developments, even the 4-wheel-drive Schwimmwagen (that otherwise proved unstoppable) failed ... what was needed was a semi-tracked vehicle like the larger half-tracked tractors used by the German Army.
The Typ-155 Kübelwagen :
There isn't much known about the Typ-155 "Schneeketten" (snow-track) Kübel ; even the Porsche Archive hasn't researched this variant to date ; but there are a couple of books (some co-authored by Ferry Porsche) that mention it at least in passing. These books fill in some blanks though there are a lot of misleading statements due to faulty memory, mixed-up author's notes / translations and destroyed documentation due to bombing near the end of the War. Perhaps one day all the loose ends will be tied together and we will know the full details.
After the trouble crossing Russia, the High Command of the Army (OKH) demanded suggestions for better cross-country performance in both snow and sand of the V.W. cross-country car Typ-82 (Kübelwagen) so, in late 1942, work began at V.W.'s Stuttgart-Zuffenhausen factory. After trials with several types of drum-type ("beer-barrel") wheel extensions fitted to some Kübelwagen & Schwimmwagen failed, a tracked running gear was developed. Other companies had earlier built slightly larger prototype vehicles resulting in the production 1-ton capacity Sd.Kfz.10 half-tracks (Demag D-11 to D-7 series) & Adler designed a full-body staff-car (A3F) on their similar small half-track chassis .... so why was the Typ-155 ever started at all ??
What we do know is that "several" Kübelwagen were converted for evaluation, plus 2 "standard" Schwimmwagen (see below) & some other tracked vehicles like Maultiers were also used in the trials. Featuring 4 distinctly different designs of track system and some sub-designs. It is possible that a particular vehicle was used to trial more than one type of track mechanism as some have fittings for another design than the one shown attached. Most designs seem to utilise components from small agricultural machinery as well as parts purpose-made by the factory (Porsche had been manufacturing small tractors for farming (under his own name) and also giant articulated "Road-Train" tractors for towing complete artillery sets since before W.W.1).
The Typ-155's tracked running gear was attached to the rear axle instead of the normal rear wheels ; additional struts attached to the axle as well as swing-arms attached to (on some types) the outside body, below the front doors, provided mounting & directional stability for the tracks. The track-sets were designed so that they could be fitted in the field to a standard Kübelwagen (which would incorporate the few extra fittings needed) in approx. 1˝ hours and removed in about ˝ hour by 2 men.
I have tried to classify the various types by assigning a designation to each, however, apart from the Typ-155/1 & the Typ166/5 Schwimmwagen, these are my designations not those of V.W. or Dr. Ing. Ferry Porsche and are purely to help in categorizing them .... all bogie-wheels are "double" types ie:- a wheel on the inside & outside of the track.
Typ-155/0:- This vehicle was apparently the initial prototype form. The type of system is very similar to many early attempts world-wide to develop a track system for agricultural use (the basic layout dates from around 1910) ; this unit may have been a commercially available mechanism. The bare chassis has light "baking-dish" track-plates while the completed vehicle has the heavy-duty steel track fitted.
Typ-155/1:- A simple but well finished version there is no extra springing in the mechanism for added suspension. Small drive-sprocket, 5 small rubber-tyred bogie-wheels, the first & last bogies being flanged to help guide the track. An external scissor-action lever assembly helps to anchor & stabilize the whole mechanism. The track itself has a "sunken" middle to each link.
Typ-155/2:- This type is quite simple, a medium size drive-sprocket plus 3 slightly smaller bogies ; all of which ride on the ground, offering the same limited ground-clearance as the 155/0. The track is a very simple "band" type (made up of "U"- channel steel tubing) with guide-horns.
Typ-155/3a:- Another simple style ; this time a large drive-sprocket close in size to the Kübel's standard road wheel. With 3 small steel bogies & a similar but slightly larger toothed sprocket (not driven) to help guide the track links as an "idler", all in contact with the ground. This style also uses the scissor-action lever for stability. The track is the simple type like on the 155/2 but apparently without guide-horns.
Typ-155/3b:- An identical mechanism to 155/3a but using different pattern bogie-wheels. The 3 center bogies have rubber tyres & the idler sprocket is now a cast type with spokes. The track is the same "sunken centre" type as fitted to the 155/1.
Typ-155/4a:- The first design to incorporate extra springing for more efficient traction & a better ride. It is based on the "Horstmann" principle used by many light Tanks of several nations. Consists of a small drive-sprocket, 5 small rubber-tyred bogies, a raised idler-wheel in front & two return rollers. The last bogie is independently mounted with a shock-absorber and the others are connected in pairs in typical Horstmann manner. This design does not seem to have been actually built, probably because the suspension was too fancy & costly.
Typ-155/4b:- Looking the similar to 155/4a but with a much simpler (& practical) suspension system. The last bogie is still independently mounted with shock-absorber but the other four bogies are mounted on a common bar which has two trailing "spring-levers" for suspension, there is only one return roller. The track is less "agricultural" & more like military track as on larger vehicles, Tanks etc.
Typ-155/4c:- The ultimate type of design using a much simplified version of 4a. Incorporating leaf-spring suspension, the bogies are again mounted in pairs, the last bogie-wheel is now raised slightly off the ground & solidly mounted, not sprung ; there are two return rollers again. This version was tested both with & without track-grousers.
During testing it was soon found that the engines needed modifying with more power (larger capacity), strengthened crank-shafts and different gearing ; a limited-slip-differential was also used. Because steering with the front wheels was impossible in deep snow and sand, there was a track-brake system controlled by levers and Bowden lines (cable), therefore the brakes and the differential needed to be strengthened. In addition, other devices such as skis (attached with chains & springs) on the front wheels, a curved skid-plate on the nose of the vehicle (helping the vehicle to slide over any accumulation of sand or snow) and grouser-shoes for the track were experimented with to improve traction as part of the development work.
These trials proved that the Typ-155 was able to cover the most difficult terrain and comparison with the performance of the NSU HK-101 Kettenkrad motorcycle-tractor (Sd.Kfz.2) was favourable. But they also proved that due to the bigger engine, extra loading of the track mechanism, friction of the snow and extra weight of the (small) trailer & cargo it would carry (apart from the manufacturing cost of the track mechanism) that it was not worth the expense of this conversion. With a full load petrol consumption was as bad as 151 ltrs/100km (3 mpg) & maximum speed fell to 8 km/per hour (5 mph) !! This was unacceptable as other vehicles were faster, had better fuel consumption and larger cargo capacity.
Contrary to several claims, the Typ-155's were never tested anywhere else and never saw service, remaining purely experimental. While these vehicles were initially issued to the Army & had Army number-plates, when seconded to V.W. for trials with the tracks they were registered with civilian number-plates which were fixed over the military ones. The vehicles were tested in sand quarries and on snow-laden mountains both in Germany (Black Forest & Kummersdorf Testing Ground) and Austria, where Porsche had been forced to relocate the V.W. factory due to Allied bombing. By this stage of the war (1944) tracked load-carriers were desperately needed and the few Opel, Ford, H-K-D (& some larger Mercedes with "Pz-II" rear suspension) Maultiers available made it essential to use obsolete (turretless) small tanks (Pz-38t, Pz-II & Pz-III) and Sd.Kfz. 250 half-tracks (& at least one Sd.Kfz. 251 fitted with a wooden cargo body) as cargo & ammunition carriers. Even Nashorn's, which had the gun damaged or simply removed (as the '88' was by then not as good as the 12.8cm gun), were used as ammo-carriers for their sister vehicles, the Hummel's.
Tracked Schwimmwagen ?? :
In one of the books co-authored by Ferry Porsche there is a report that indicates that 2 Schwimmwagen (Typ-166/5) were converted to half-tracks too ; though no reference to these vehicles exists in the Porsche archives & if they ever existed, were never given a "Typ" number. This report probably came about due to mixed-up notes or faulty translating by the books author and most probably refers to the Schwimmwagen Type 166/5, that had the barrel-type extensions fitted on the wheels in order to try and give the vehicle a larger "footprint" thus lowering the vehicle's perceived weight upon the snow. These 2 vehicles proved to be not suitable as reportedly the 'boat-shaped' nose of the hull tended to "burrow" into the snow and the greater surface area of the under-body in contact with the snow caused greater drag than the flat bottom of the Kübel which behaved like a sled, sliding over the surface.
If you have any other information, find an error, have more or better quality photos of these vehicles please let us know.
|Typ-155/3b fitted with ski's on trials in the Black Forest, January 1943.||Typ-155/4c with grousers races a Kettenkrad up a sand hill. (Black Forest, 1944)|
|Typ-155/4c with grousers crests a sand knoll. Note the tow-bar & exhaust-muffler set-up. (Black Forest , 1944)||Typ-155/4c with grousers climbing at full speed. Note the hollow, see-through nose-skid. (Black Forest , 1944)|
|Rear 3/4 view of the Typ-155/1 (the official designation). A good view of the tow-bar & track style.||Possibly the Typ-155/3b with broken ski on the left side. Note the civilian number-plate on top of the military one.|
|Side view of the grouser shoe used on the Typ-155/4c fitted to a standard Opel or Ford Maultier (RSO in background). (1944)||The Typ-166/5 Schwimmwagen fitted with "deep-treaded" drum-type wheel-extensions on trial in the snow.|
|A shot from the rear of the grousers attached to the track of a standard Opel or Ford Maultier. (1944)||The Typ-155/0 initial prototype vehicle fitted with the heavy-duty steel track.|
|A spare track grouser. Note the wheels of an unknown type of tracked vehicle in the top left corner of the picture. (1944)||The Typ-155/1 (the official designation) from the side. Nice & clean but note the damage to & around the rear door.|
|The Typ-155/3a in front of the factory. Dr. Ing. Ferry Porsche in the driver's seat.||Typ-155/2 , a very simple type. Note the suspension mount in the wheel-well and the peg just behind the front mud-guard to secure the snow-skis.|
|The second sub-type of the fourth design, simplified from Typ-155/4a.||The Typ-597 Jagdwagen of 1955. It combined the looks of the Kübel with the amphibious capability of the Schwimmwagen.|
|Factory drawing of the Typ-155/4a track-system, typically well designed and expensive to produce!!|
|Factory plans of the general layout for the Typ-155/4c. Note the wide track (grousers fitted) and the "crest" on the nose skid.|
CREDITS :- thanks to ....
Thomas Hartwig for translating text.
Jens Torner , Publicity & Archive Dept. , Porsche AG for providing information & photographs.
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