Tractor Tanks

[Ricky]

This is a topic I have been playing with for a while in my head, and I had even gathered a large amount of information on - but then lost my USB stick.

My basic point is that tanks based on existing tractor designs are generally less able than tanks designed from scratch. For this topic ‘tractor’ means a fully-tracked vehicle.

Starting in WW1 with the very first tanks, there were some tanks based on the Holt tractor chassis – Schneider, St Charmond, A7V – and those designed from scratch – the ‘Rhombus’ tanks, the Whippet and the FT-17. It is worth noting that this division of WW1 tanks exactly mirrors a division along production numbers, which in itself speaks a story. Essentially, the Holt chassis proved a poor base for an armoured vehicle, particularly in the conditions of No-Mans Land, and tanks based on it were generally large, unwieldy and got bogged down a lot.

Between the wars, lots of nations experimented with tanks and tank design, with many utilising tractor chassis as a short-cut. Both Germany and the USA even produced a range of experimental SPGs based on tractors. Few of these designs progressed beyond prototypes, unless you count a number of armoured artillery tractors that found favour in some nations, particularly within South America. The only real exception to this was the Disston Tractor Tank, 26 of which were built in the USA in the mid-1930s. 16 of these went to the USMC and the remainder to Afghanistan (where one still exists in a museum). It was the Disston which served as the template/inspiration for the Bob Semple...

During WW2, only two ‘Tractor Tank’ designs were built. There was the Bob Semple, New Zealand’s last-ditch home defence measure, and the NI tank in the USSR, built in Odessa during the siege. These two vehicles were in some ways the two extremes of the Tractor Tank design. The Bob Semple was slow, top-heavy, cramped, underarmed and frankly more of a danger to its crew than the enemy. The NI tank was much more practical, with most models having a reasonably-sized gun and adequate armour. 68 were produced, with a variety of armaments, and they actually proved useful (though typically short-lived) in action.

Essentially though, Tractor tanks were still generally large, unwieldy and got bogged down a lot compared to their contemporaries. In addition, they were usually lightly armoured to avoid overloading the chassis. Post-WW2 there have been few (if any) serious Tractor Tank designs.

So why did anybody bother? The basic reason is simple – Simplicity.
Do you need a tank in hurry? Do you have no experience in making tanks, no facilities nearby to make tanks, no money/time to develop a workable tank and no money/time to buy workable tanks from elsewhere?
Then simply take one tractor chassis, slap on some armour plate and a gun or two (or three, or however many you can fit), and hey-presto! One ‘tank’.

For the desperate, the hard-up or even those with low-tech enemies, the Tractor Tank was useful (I won’t say ideal).

[lynn1212]

no real surprise there. the two designs share very few points in common. a tractor runs at slow speed, constant speed, over prepared ground, carrying almost no load. it is built to be simple, easy to maintain, with a simple drive line. most use basic brake steering. a tank is much heavier, should be faster, has to run in conditions a tractor would avoid, needs a crew instead of a driver, has to find room for weapons and ammo, and needs to pack everything into a steel box. about all they share is the tracks and even they are different.

[Christian Ankerstjerne]

It would also be interesting to compare the tractor-based tanks to the truck-based armoured cars used during both World War I, the inter-war years and the beginning of World War II. The British Rolls Royce armoured car is probably the best known, but there were others as well. Especially the various resistance groups had one-off armoured cars based on commercial trucks. Below is a photograph of one such vehicle from Denmark, based on a Ford truck with iron plates added for protection (it did little good, as it is riddled with bullet holes, which is received in the rather chaotic days after the German occupation ended).



Incidentally, I have a photograph of my grandfather from his days in the Danish resistance with another truck, also with iron plates, and armed with a 37 mm naval gun.

[Ricky]

Truck-based armoured cars are in 2 categories:

Commercial designs
Generally an armaments company will pick a sturdy & reliable truck chassis and create an armoured car from it. Many of the more notable armoured cars stem from this line - the Geman 6-wheelers, the Marmon-Herringtons, the Russian BA-64 etc - and generally they are good, well-liked and effective designs. Though obvously not always.

Desperation designs
Generally a normal lorry will be converted into an armoured vehicle, usually by sticking metal plates to it. The designs can be very simple or fairly complex, even including mid-caliber guns and revolving turrets. The simplest that I know of was during the 1916 Easter Rising in Ireland, when the British took a tanker lorry, cut loopholes in the cylindrical metal tank, and put a squad of riflemen inside. It was not a great success, as the tank was not bulletproof.
Generally these vehicles are useful where the enemy is either not expecting them or not equipped with anything above a rifle or light mg. Otherwise they are a rather short-lived diversion.

[Christian Ankerstjerne]

True about the improvised designs. Especially since they'll often only be not-bulletproof when the bullet goes in, but will keep the bullet inside once it has penetrated the armour. They'll scare untrained militias and mobs, though, and can boost the morale of ones own troops.

[aglooka]

There was also a improvised tank destroyer built by the German garrison of Lorient. This was based on a Schneider carterpillar tractor dating back to the first world war (basically a Schneider tank without armour).

The armour lay out was faceted, looking a bit like that on the German armoured half-tracks. It was open topped and mounted a PAK 40 with what looks like its original shield.

greetz

Aglooka

[Christian Ankerstjerne]

I hadn't heard about this vehicle before. Do you know where I can find out more about it?

[aglooka]

I have two mentions of this vehicle, both with the same picture.

1. Crow and Icks, Encyclopedia of Tanks. The vehicle is shortly mentioned in the datapages with a pic. Described as "Poche de La Rochelle, Improvised SP on Schneider 19.4cm SP chassis, box hull bevelled inward, wide shield, 7.5 cm Pak 40."

2.Spielberger, Beute-Kraftfahrzeuge und-Panzer der deutschen Wehrmacht. Mentions: "Einer ebenfalls aus dem Ersten Weltkrieg stammenden <<Caterpillar-Schneider>> - wurde noch in 1945 in La Rochelle behelfsmassig gepanzert eingesezt. Afgebaut war eine 5 cm-Pak für Kustenverteidigung". At the bottom of the page, the same picture in as in the Crow and Icks book is shown, but of better print quality, next to a a picture of the Caterpillar Schneider without any armor.


Remarks: 1. sorry for my bad memory, it seems to be la-Rochelle where this thing was improvised.
2. Froms the picture, and comparing this with the suspension of the caterpillar Schneider, it is clear that the thing was built on this chassis and not that of the 19.4 cm SP. From the size of the Gun i would also guess that it is a Pak 38 instead of a Pak 40. But the shield puzzles me a bit. Maybe some specialists on the forum can tell wether this is the original shield of the gun or an improvised one



many greetings

Aglooka