Culqualber and Uolchefit Tanks

Kingdom of Italy (1941)
Armored Tractor – 2 Built

There have been many attempts over the years, in a variety of countries, to turn track-laying industrial equipment into expedient armored vehicles. Their tracks and ability to carry, tow, or move heavy loads has produced expedient military vehicles based on everything from cranes to farm tractors. More common though, were those based on track-laying earthmovers and bulldozers. The production of these vehicles has usually been driven by the lack of alternative armor from actual tanks, and the campaign in Abyssinia was no different.

Strategic Background

Italy had invaded Abyssinia (modern-day Ethiopia and Eritrea) back in 1935 and fought a rather long war and insurgency against a very determined native defense force. Although they had used a number of armored cars and light tanks, such as the CV3 series, there was still a serious shortage of armor in the colony. Some additional stocks had been delivered prior to the outbreak of World War 2 in 1940 (Italy didn’t join in until 1940), but even with these, stocks of armor were still inadequate.
Far from Italy, at the end of vulnerable supply routes, it was effectively cut-off by Great Britain when Italy declared war in June 1940. It was an enormous territory to protect, sandwiched between Anglo-Egyptian Sudan to the North-West, British and French Somaliland to the North, and British held Kenya to the South. Supplies would have to skirt around the Cape of Good Hope to avoid the British held and controlled Suez Canal, which meant that the colony was effectively isolated and vulnerable. Hopes of a quick victory in Egypt to wrestle control of the Suez Canal from the British would prove vain at best, so, in the meantime, the colony was on its own. The situation was no better for the British either. Just because they effectively had the colony surrounded and cut-off did not mean it was not a threat. Positioned and dominating the Horn of Africa, this Italian territory posed a significant threat to the vital British supply route through the Gulf of Aden to the Suez Canal and up the East African coast to South Africa, Rhodesia, and Kenya. Removal of this threat to a vital supply line was essential for the British.
The 1.7 million square kilometer area comprising most of present-day Ethiopia, Eritrea, and Somalia was collectively known as Africa Orientale Italiana (AOI) and was divided into 6 military regions. These were Eritrea (capital Asmara), Amara (Gondar), Scioa (Addis Ababa – regional capital and capital of Abyssinia), Galla-Sidamo (Jimma), Harrar (Harar), and Somalia (Mogadishu). Italian forces were widely dispersed over this rugged and unforgiving terrain with just 39 light tanks (CV3 and FIAT 3000) and 24 M11 medium tanks. The bulk of the Italian armored force in the region was made up by armored cars, 126 of them in total, and all of these vehicles and troops (just over ¼ million Italian and Native) had to guard an area nearly 7 times to size of France.
Benito Mussolini’s ideas of a quick war meant that the AOI was fine and could be left to its own devices until after Britain had sued for peace. Italy would keep its possession and take a slice of France as well as maybe some more territory in North Africa or in the Mediterranean. Unfortunately for Mussolini and for AOI, Britain did not sue for peace. It was not going to be a quick war with easy territorial gains for Italy, but a long fight in which all of her colonies were going to fall one by one, including AOI.
For the troops in AOI, the war actually started fairly well. The borders of British Kenya and Anglo-Egyptian Sudan were crossed and small border areas occupied, and in August 1940 a full scale, successful invasion of British Somaliland was mounted. French Somaliland was more complicated but was effectively taken out of the war by the terms of the Franco-Italian armistice.
Early successes aside though, it was not to last and the British counterattacked in force simultaneously from Kenya in the South, Anglo-Egyptian Sudan in the North-West and occupied British Somaliland. Despite some determined resistance, it was a fool’s errand for Italy. The AOI, led by the Duke of Aosta, never stood a chance of winning, the question had only been one of how long they could last. Pressed from all sides and with an ever-dwindling number of resources, Italian forces had withdrawn progressively back towards the highland area
Addis Ababa fell to the British on 3rd April 1941 as the Duke withdrew to the stronghold of Amba Alagi which also fell to the British on 19th May 1941. The war for AOI continued though as British and Ethiopian forces pressed the Italians back towards Gondar by November 1941. Gondar was the capital of the Asmara region and lay to the north of Lake Tana, guarded by mountain passes at Wolchefit and Kulkalber.

Protecting Gondar

Italian forces in AOI were poorly equipped in general, with very little motor transport and little armor. Following the loss of Kassala, Somaliland, and Addis Ababa, there was even less available. Like so many other places when there was no armor to be had, it was improvised. In this case, twice.
Two ‘tanks’ were manufactured and named for these key passes guarding Gondar, known as ‘Culqualber’ and ‘Uolchefit’ respectively.

Uolchefit

Uolchefit (Wolchefit) was made from a Caterpillar RD7. The RD series of tractors began in October 1931 in the United States and was an extremely popular and well-selling machine with ‘RD’ used to describe the names of this series from 1935. One of the first popular, powerful, and reliable diesel engined tractors, they sold well around the world. A couple of machines had made it to Ethiopia before the war and were used in the grading and construction of roads.
The RD-7 was powered by the reliable Caterpillar 13.6 l D-8800 (831 ci) 4 cylinder vertical diesel engine. Tested in Nebraska in 1936, this engine delivered a maximum of 95 hp at 1000 rpm (belt horsepower) and 78 hp at 1000 rpm (drawbar horsepower). Adjusted to sea-level, this was 100 hp and 83 hp maximum respectively, with the highest permissible rating as 86 hp and 62 hp respectively. This engine was coupled to a 5-speed gearbox (4 forward, 1 reverse) and a top speed of 5.5 mph (8.9 km/h) forwards in 4th gear and 2.2 mph (3.5 km/h) in reverse.
Without the armored body, the RD-7 was 4.12 meters long, 2.46 m wide and 2.03 m high (to top of bonnet), with a ground clearance of 39 cm (1940 data).

Culqualber

It is mentioned in some sources that the Culqualber tank was based not on the RD-7 but on the D-6. The D-6, also made by Caterpillar, weighed just over 8 tonnes and was tested in Nebraska in September 1941. During that testing, it delivered a maximum 78 hp at 1400 rpm (belt horsepower) and 63 hp at 1402 rpm on the drawbar. Adjusted to sea-level, this was 67 hp and 81 hp maximum respectively with the highest permissible rating as 69 hp and 50 hp respectively. Powered by a Caterpillar 7.7 l D-6600 (468 ci) 6 cylinder vertical diesel engine coupled to a 9 speed gearbox (5 forward, 4 reverse), the D-6 was capable of speeds up to 5.8 mph (9.8 km/h) in fifth gear and 5.4 mph (8.8 km/h) in reverse and was carried on 16 inch (409 cm) wide tracks. The D-6 was slightly smaller than the RD-7, measuring 3.78 m long, 2.04 m wide, and 1.91 m high (to top of bonnet) with a ground clearance of 31cm.

Layout

Both vehicles were made in the same way but differ in their features. Culqualber featured a very pronounced inverted ‘V’ shaped roof over the boxy superstructure. Armor covered all sides and roof with the engine covered by a large armored grille. The rear of the machine was pointed, and in some photographs, a spot lamp can be seen in the middle of the superstructure. The driver’s position remained unchanged from when it was a tractor and he was provided with a rectangular viewport to see through and a machine-gun on each side.
Photographs also show that the roof contained two rectangular hatches roughly centrally over the V-shaped roof which served as the only access or exit to and from the vehicle for the crew. The two machine-guns, usually mounted alongside the driver in the front, could also be moved to either of the two firing ports in the rear or the two firing ports in each side. Culquaber appears to be a smaller vehicle (D-6 rather than RD-7) than Uolchefit which would match the description of it being based on a D-6. There appears to have been space for just three crewmen, a driver, a machine-gunner, and a commander, who would also act as another machine-gunner. One particular photograph of Culqualber shows it without the spot lamp and what appears to be a more pronounced roof. It is unknown whether this is the vehicle early or late in her life but, as it is the only photo showing this, the assumption is it was taken before she was finished. A confusion, however, is what appears to be camouflage painted on one side of the vehicle not seen in other photographs. This leaves open the possibility that a third, unknown vehicle was also produced

Uolchefit is noticeably longer and wider than Culqualber with space alongside the engine for a machine-gun position on each side at the front. Like the Culqualber, the casemate has a central driver’s rectangular vision port and is flanked by machine-guns. It has two large firing ports and two smaller vision ports in each side with the rear-most one on each side mounting another machine-gun. The rear of the vehicle sticks out over the rear of the tracks narrowing to a small rear panel. Each panel has a vision/firing slit and the sloping roof over the back had another slot capable of mounting a high angle machine-gun, something very useful in the mountainous terrain of the region. Assuming each gun would be manned at the same time, this makes for a crew of driver, commander/machine-gunner, and up to 6 other machine-gunners.

Armor

The original Caterpillar D-6 and RD-7 tractors carried no armor at all, so, in order to be bulletproof, armor had to be fabricated. Being cut-off from supplies, the number of trucks available to the force had diminished greatly. Spares could not be found, so trucks were salvaged as they broke down, and shortages of tyres were serious, resulting in a large graveyard of scrap trucks available. With no supplies of armor plate available, the solution was the ingenious use of the leaf spring suspension units taken from trucks and split apart. Straightened out, these springs were then welded to form the armor which was probably supported on some kind of framework also made from the scrap trucks. The result was not pretty, but was functional and provides a unique appearance to the armor. The armor is therefore estimated to be about 10-12 mm thick.

Armament

Uolchefit was fitted with seven 6.5 mm FIAT Model 1914 machine-guns. Two were fitted at the front with one either side of the engine, 2 more in the casemate above the driver’s position, one in each side and a seventh in the rear, facing backward. Culqualber, on the other hand, was fitted with two 8 mm FIAT Model 1935 machine-guns. The two were usually mounted in the front at the level of the driver, but could be moved to the rear or sides as needed. An unknown amount of ammunition was carried in each vehicle.

Combat

Both vehicles were constructed on their tractor donor chassis by Officine Monti di Gondar (workshops of the Monti company in Gondar) in late June to early July 1941 and both were soon pressed into combat. In a memo from the Commander of forces in Amhara, Gondar, dated August 23rd, 1941 to the Italian High Command, he reported setting up a platoon of tanks by taking two Caterpillar tractors and applying armor to them. He readily acknowledged that although they might have only a small military value would still provide positive support for the morale of Italian troops and likewise damage the morale of the British and Ethiopian forces. He also asked if more such vehicles would be available, presumably to create more tanks.*
A further memo from the Commander in Amhara, Gondar, dated 18th September 1941, stated that two vehicles had been made and that, although they could only manage 6 km/h, they provided valuable cover from fire as they were impenetrable to machine-gun fire and rifle bullets at 200 m.
An additional armored vehicle based on a truck was also made and all three vehicles saw combat on 13th September at Lake Tana, although one source states that only Uolchefit was present at this western garrison at Fercaber, with Culqualber in the main garrison at Culqualber pass. What is certain is that no photos show both vehicles together.
The conditions inside the vehicles were bad. During the action on the 13th, the heat and fumes inside the vehicles meant crewmen were fainting inside them. The report dated the 18th does not say that they were knocked out, suggesting that they were both still fully operational on that date.
Records for the use of these tanks in combat is unsurprisingly rare. It is known that they saw combat on 13th September at Laka Tana. The Wolchefit Pass fell on 28th September 1941 after an assault by the British after which they marched on Gondar and attacked on 27th November 1941. The resistance there lasted just three days and the loss of Gondar marked the end of official Italian resistance in AOI. The two tanks, Culqualber and Uolchefit, must have been lost or abandoned between 13th September and 27th November.
*’History of the Combat Units of the MVSN (1923-1943)’, published in 1976 states that 6 caterpillar tanks were made but this appears to confuse these tanks with other improvised armored vehicles for a total of six.

Conclusion

The Uolchefit and Culqualber tanks were not the only tanks made from the Caterpillar RD series. Thousands of miles away and compelled by similar reasons, a far more famous vehicle was made in New Zealand. The famous ‘Bob Semple Tank’ was also based on this chassis. The chassis saw other attempts too. The firm of Disston produced a ‘tank’ based on the RD tractor too which met with some limited commercial success before the war. The compelling need to produce improvised armor has led to many attempts to produce a tank based on a sturdy tractor chassis and, like the Bob Semple tank before it, these Italian designs were short-lived. The only claim to fame these have though is that they stake a claim to the first ‘tank’ produced on the continent of Africa.

Specifications (Uolchefit, RD-7 Based)
Dimensions (L-W-H)	4.12 x 2.46 x 2.03 meters
Total weight, battle-ready	9.5 tonnes (w/o armor or guns)
Crew	Up to 8 (driver, commander/machine-gunner, 6 other machine-gunners)
Propulsion	Caterpillar 13.6 litre D-8800 (831 ci) 4 cylinder diesel, 61.94hp at 1000rpm (drawbar)
Top speed	5.5mph (forwards), 2.2mph (reverse)
Armament:	7x FIAT M1914 6.5mm machine-guns
Armor	Leaf-spring suspension steel <20mm

Specifications (Culqualber, D-6 Based)
Dimensions (L-W-H)	3.78 x 2.04 x 1.9 meters
Total weight, battle-ready	8.05 tonnes (w/o armor or guns)
Crew	3 (driver, commander/machine-gunner, machine-gunner)
Propulsion	Caterpillar 7.7 l (468 ci) 6 cylinder vertical diesel, 49.93hp at 1400rpm (drawbar)
Top speed	5.8mph (forward), 5.4mph (reverse)
Armament:	2x FIAT M1935 8mm machine-guns
Armor	Leaf-spring suspension steel <20mm

Sources

www.caterpillar.com
Nebraska Tractor Tests Report No.255: Caterpillar Model RD-7 (Diesel), January 1936
Nebraska Tractor Tests Report No.358: Caterpillar Model D-7 (Diesel), January 1940
Nebraska Tractor Tests Report No.374: Caterpillar Model D-6 (Diesel), January 1941
How Italy was defeated in East Africa in 1941, Ian Carter, IWM
History of the Second World War: Mediterranean and Middle East Vol.1, Sir James Butler
Gli autoveicoli da combattimento dell’Esercito Italiano, Nicola Pignato & Filippo Cappellano
History of the Combat Units of the MVSN (1923-1943), E.Lucas-G. De Vecchi, 1976
I Corazzati Di Circostanza, Nico Sgarlato