T-13 tank destroyer

The T-13 was a tank destroyer in use with the Belgian armed forces before WWII and during the Battle of Belgium. It was designed by Vickers, and produced by Vickers, Miesse and Familleheureux and outfitted with FRC Herstal weaponry. The earlier T-13s were based on imported Vickers tracked vehicles that were outfitted with armament and armor in Belgium by the Miesse company, later versions, from the B3 version on, were fully license-produced in Belgium by the Familleheureux factory. Total production numbers are unclear and have been underestimated for political reasons, both before and after WWII, but are generally estimated at 300 vehicles, although not all were available or fully outfitted on 10 May 1940, the start of the Battle of Belgium. Nazi Germany used the vehicles as well after the occupation of Belgium, but to what extent remains unclear.

History
In general - keeping a close watch on German political and military developments - the need for armored tracked vehicles or tanks was widely accepted by the Belgian military establishment. The political view on the matter however was slightly more complex: the Belgian government tried frantically, keeping in mind the total destruction of the small country in the First World War, to keep Belgium neutral from 1936 on and therefore out of the upcoming European conflict. Politicians from the right wing political parties wished Belgium would abstain from buying offensive weapons like tanks and bombers, so as not to provoke Germany into starting a new war, politicians from left wing parties rejected heavy arms on an ideological basis.

From this point of view the T-13 tank destroyer could be described as the result of Belgium's neutrality doctrine: the vehicle had to be light, and therefore lightly armored, and was built without a fully enclosed fighting compartment, much like the German Panzerjäger designs, thus resulting in a tank destroyer class vehicle, rather than a true tank. Also, as with the T-15 Light tank units, the psychological words tank or armored/mechanized unit were never to be used in official unit designations, with the words armored/tracked motorcar and the historical cavalry being favored.

Vickers Carden Loyd 1934 artillery tractor
Since the Belgian armed forces realized the need for further mechanization of the army in the 1930s, a number of foreign platforms were looked at. In 1934, the Belgian Army signed a contract for 21 or 23 Vickers Carden Loyd 1934 utility tractors with the British firm Vickers. These were meant as artillery tractors for the Chasseurs Ardennais mountain troops, to tow the recently acquired Bofors 75 mm Model 1934 mountain gun. Impressed with the vehicle's performance on both hilly and flat terrain, the Belgian Armed Forces decided to take the concept a little further and experimentally outfitted the tractor with the F.R.C. built 47 mm anti-tank gun, much along the lines of the earlier but ultimately unsuccessful SA F.R.C. 47mm experiment. Not much is known about the basic model Vickers 1934 artillery tractor, apart from the fact that the Belgian Army seems to have been the sole user of the type. In its basic configuration, the Vickers 1934 artillery tractor was unarmored and could generally be described as an open, tracked light truck. It was outfitted with a 51 hp 5 cylinder Meadows gasoline engine with an internal volume of 3300 cc, and had an empty weight of 2 tons. Apart from the Bofors 75 mm equipped Chasseurs Ardennais, no other Belgian armed units were outfitted with the type, the Belgian armed forces instead preferring the smaller and far less expensive Vickers/Familleureux utility tractor as their main tracked transporter later on. However, given its successful use with the Chasseurs Ardennais mountain troops, the Belgian Armed Forces decided to order another 32 vehicles, which became the basis for the T-13 B1.

T-13 B1/B2 design
Pleased with the performance of the Vickers 1934 artillery truck, the Belgian Army started to equip the newly ordered 32 vehicles with the FRC Herstal built 47 mm Model 1931 anti-tank gun. Since this was a fairly heavy piece of equipment, and because of the general lay-out of the Vickers artillery tractor, with its center of gravity being well halfway the vehicle, the decision was taken to simply install the gun and its turret backwards on the vehicle, so as to keep enough space for crew and ammo.

The general lay out of the vehicle naturally mimics that of the Vickers vehicle it was based on. The suspension was made out of Horstmann suspensions resting on bogies with two rubber-lined wheel sets per bogie. This design, exclusively used on lightweight vehicles, was also used on the  Light Tank Mk VI of the Royal army and was invented by Sidney Horstmann. Apart from being relatively easy to built, compact and lightweight, it had the advantage of having a long travel, and of being easy to replace when damaged in the field. The drive sprocket was in the front, but there were no idlers or return rollers. Motor power came in the form of a Meadows 5 cylinder gasoline engine, producing 51 hp, coupled with a four speed preselector gearbox. Steering was a combination of declutching the drive to one track and braking to increase the turn. The traverse of the turret was man powered by the three man crew The T-13s were not equipped with a radio.

Armor protection was limited, but still better than that of the under armored T-15 light tank. Frontal armor was 12 mm of hardened steel, both on the frontal bulkhead and on the turret. Side armor on the vehicle basis and turret was restricted to 6 mm of steel, to minimize the weight, costs and political impact of the vehicle. This meant that the T-13 crew was only fully protected against indirect blast and splinter damage, adequatly protected against small arms fire from the frontal aspect but not from the sides, and most importantly was not protected at all against most light anti-tank rounds, such as the .50 BMG, the Boys anti-tank rifle .55 Boys or the German 13.2 mm TuF. Also, the side armor shields had to be folded down to permit the full 360° traverse of the turret, further exposing the crew to enemy rifle fire. If the (lightly) armored side shields were left upwards, traverse of the turret was limited to 120° in the frontal aspect.

Armament was fairly heavy for this lightweight class vehicle giving the T-13 tank destroyer, rather surprisingly, a very nasty bite indeed. Main armament was the 47 mm Model 1931 anti-tank gun, which fired 1.52 kg armor piercing shells and could penetrate 47 mm of armor plating from a distance of 300 m, for its time an impressive performance. The maximum firing range of the gun was 2000 m, and as both armor piercing and high explosive rounds were available the gun had a useful anti-infantry capability as well. The secondary armament consisted of a single turret mounted light FN built M1918 Browning Automatic Rifle, in essence a Belgian license built Browning BAR machine gun in a special 7.65x53mm "Belgian Mauser calibre" instead of the American .30. The machine gun fired 500-650 rounds per minute in automatic mode.

Production
After the prototype T-13 B1 passed all the tests of the Belgian Army, in 1935 production on the tank destroyer was authorized to proceed: the Miesse company near Buizingen (close to Brussels) delivered 32 T-13 B1s, all based on imported British built Vickers 1934 artillery tractors. The T-13 B2 model was a further development of the B1, but differs only slightly from the B1 model: most importantly the turret was redesigned to give the vehicle a somewhat lower frontal silhouette. All 21 (23 according to some sources) T-13 B2s were apparently converted from the earlier ordered Vickers artillery tractors for the Chasseurs Ardennais mountain troops, tracked transport of the M34 75mm Bofors mountain gun now passed on to the smaller but more economical Vickers/Familleureux utility tractor. T-13 B2 assembly ended by 1937.

T-13 B3 design
Although the Belgian armed forces were generally very pleased with the capabilities of the existing T-13 B1 and B2s, there were obvious issues with both models of the tank destroyer. Since the original Vickers artillery tractor was not designed for the tank destroyer mission, it was faced with a very common vehicle design problem called 'weight creap', which in essence is the stepwise accummulation of weight every time a new feature or capability is added to the general prototype design. This led to the first model T-13s being underpowered, somewhat unstable as a gunnery platform and prone to mechanical malfunctions because of overloading and wear and tear. Full weight was 4,5 tons for a 51 hp gasoline engine. Much more important however was the vulnerability of the three man crew. Last but not least, importing fully assembled vehicles was a technically interesting shortcut but too expensive a solution to field a tank destoyer in adequate numbers, especially with the Belgian economy performing rather poorly because of the worldwide great depression and the resulting drop in foreign demand for industrial products. The design obviously needed some rethinking.



So in 1936 a new vehicle was imported from the traditional supplier, the Vickers company - it should be noted that Belgian experiences with ordering from competing foreign companies such as the Renault company had been very disappointing (see AMC 35). This was the Vickers-Carden-Loyd Light Dragon Mk. II B (see Light tanks of the United Kingdom) in the export version, equipped with a 88 hp Meadows 6 cylinder gasoline engine and a "crash" type gearbox. The general design of the vehicle was almost identical to the T-15 Light tank already in service with the Belgian armed forces, also designed and produced by the Vickers company. The suspension was made out of Horstmann suspensions resting on bogies with two rubber-lined wheel sets per bogie. The drive sprocket was in the front, the idlers were placed in the rear, with three return rollers. Steering was again a combination of declutching the drive to one track and braking to increase the turn.

The bigger track area, the inclusion of return rollers and the bigger and stronger engine convinced the Belgian armed forces that this platform would be superior in the tank destroyer role. Also, since the Familleheureux factory, a vehicle and tractor company, was already producing the license built Vickers utility tractor, the decision was taken to buy a license for production at this company instead of directly acquiring all vehicles from the U.K. This would allow for a bigger and more economical production run compared to the T-13 B1/B2 version.

The definitive T-13 B3 was structurally very different from the earlier B1 and B2 versions, with the B3 suffix obviously chosen to play down the fact that a new tank destroyer was being produced rather than a variant of the older systems. This was again, as explained earlier, both for domestic economical and political reasons as well as to not provoke Germany into a new war. The chassis of the T-13 B3 was bigger, with, apart from the redesigned turret, a box-on-box like appearance. The gun was no longer pointed rearwards as in the first two versions. Armor was only slightly upgraded to 13 mm armored steel on the frontal surfaces and 7 mm steel on the sides, still insufficient to cope with anything but small arms fire and blast and shrapnel damage. However, the chassis was big enough to accommodate the four man crew without the need for the side armor panels, which also allowed the gun to traverse 360° without lowering the (still very low) level of armor protection for the crew in the process of gun laying. The backside on the other hand was still left open, since the vehicle was non the less meant to be a light tank destroyer.

The most important and obvious difference was the bigger and more powerful engine, which allowed for a greatly reduced wear and tear and a rather more stable gun laying platform, and above all for a better manoevrability in the field. Top speed for the T-13 B3 was, because of operational reasons, kept about the same as for the B1-B2 versions: 41 km per hour as supposed to 40 km per hour. The armament, apart from lay out and sighting systems, was left untouched, although more ammo could be carried. Autonomy was increased: from 240 km for the B1-B2 versions to 400 km for the B3 version. Total weight became 5,08 tons.

Production
Given the need for the Familleheureux company to set up production after acquiring a Vickers license in 1936, delivery of the first production T 13 B3s did not commence until 1938. After the second world war broke out in September 1939, production was stepped up so as to equip as many army units as possible with the new tank destroyer. Since acquiring its first T-13 B3s, the Belgian army was finally satisfied with the resultant tank destroyer and kept on ordering. Production of the B3 ended at the start of the Battle of Belgium, after a total of 250 to 255 units were produced by the Familleheureux factory. Together with the earlier B1 and B2 'production', this made, in theory, for a total of 303 to 311 T-13 vehicles. However, a few dozen of these T-13s were still at the factory in the process of being outfitted when war broke out. About two dozen others were on their way to being delivered to new units, but since there was no more time for driver, gunner or maintenance crew training they ended up being used as reserve vehicles for units already equipped with the T-13 or as spare part hulks. In total, it seems that only about 220 T-13 B1/B2/B3s were actually fielded in time with operational units. Still, this made the T-13 the most numerous armored tracked vehicle in the Belgian armed forces inventory.

Deployment and operational history


A total of 16-18 T-13 companies with 12 vehicles each have been fielded, together with a number of single vehicles and squads. These T-13 companies were mostly added to some of the existing infantry divisions: the 1st, 2nd, 3rd, 4th, 7th, 8th, 9th, 10th, 11th and 18th infantry division all had a single T-13 company on 10 May 1940. Only the 'Chasseurs Ardennais' 1st mountain division and the two cavalry divisions had 2 or 3 companies each. Together with the 42 fielded T-15s light tanks both Belgian cavalry divisions had about 50 armored tracked vehicles each, with the infantry mostly transported on motorcycles, and heavy weapons on trucks and a number of lightly armored but wheeled vehicles. Operationally, the Belgian armed forces, apart from the cavalry units, did follow the rather ineffective World War One "penny packet" doctrine, also used in the French army at the time. Instead of using the armored units independently to profit maximally from their speed and mobility, the units were diluted and used to "stiffen" the infantry units: this led to an adaptation of a rather inflexible and linear way of defense, greatly reducing their speed, mobility and overall, their effectiveness. The problem was a psychological command problem also, since infantry commanders were not keen on risking the few armored units they had at hand.

At war, the T-13 was still prone to malfunctions and breakdowns, especially the elderly and underpowered B1 and B2 versions, although the hastily delivered T-13 B3 equipped units - which in some cases had been training on their new equipement for a few days only - had problems as well. For example, the 8th company of the 2nd regiment 'Grenswielrijders/Cyclistes-Frontière' already had a broken down T-13 on the very first day of the Battle of Belgium, and had only four out of 12 left after 8 days of fighting: although some of these were knocked out in battle, at least half of them were lost due to mechanical breakdowns or to Luftwaffe bombing raids. The open topped T-13s were indeed very vulnerable targets in an air attack, and the overwhelming air superiority of the Luftwaffe during the war in western Europe led to high losses. The vehicle was obviously almost as vulnerable to artillery or even light mortar fire.

The lack of a radio was another very important issue that often led to immobilized units, waiting for a single motorcyclist to act as a liaison. Very often armored units were only a few kilometers away from the fighting but were not aware of this fact or not allowed to proceed without orders. However, this was true for most western armored units during the battle for western Europe: indeed only the German Panzer groups were adequately equipped and had a good enough understanding of how important wireless communications were to be in a mobile battle. Most importantly however, the T-13s, very similar to British Light Tank Mk VI and French Renault R35 and Renault FT tanks, proved to be underarmored. Therefore, in spite of the big gun, they lacked the capability to act as a true mobile counter-armor weapon. Very often, when T-13s, T-15s and even the heavier Renault AMC 35s of the Belgian army tried to counterattack, the German 37 mm PAK and likewise equipped armored units inflicted heavy casualties. It should be noted however that because of all political limitations on heavy weaponry mentioned earlier, neither the T-13 nor the T-15 had been designed for this mission.

On the other hand, the 47 mm gun proved to be very valuable, and was effective against both light and heavy armored enemy units. On 10 May 1940, after it had crossed the small country of Luxemburg at night without encountering much resistance, the reconnaissance group of the German first Panzer division got pinned down by a single T-13 of the 4th company of the first mountain division 'Chasseurs Ardennais' at the border town of Martelange, a couple of armored vehicles getting knocked out in the process. On a different occasion, in the afternoon of 12 May 1940 the 3rd regiment 'Lansiers/Lanciers' of the Cavalry knocked out a German reconnaissance group that was invading on the road between the towns of Zoutleeuw and Drieslinter, and succeeded in wiping it out completely, finishing off remaining infantry with machine gun fire. On one occasion, a single 47 mm hit pierced the hull of a Panzer IV on both sides of the vehicle, still continuing its trajectory afterwards.

Also, with four crew members assigned to each T-13 B3 (B1 and B2 versions had a crew of three), workload was well divided and when adequately trained, most T-13 equipped units were able to make good use of their tank destroyer. Confronted with soft targets, the T-13s fared well: T-13s participated in the successful counterattack at Kwatrecht near Gent on 20 May 1940, which succeeded in throwing back the Wehrmacht's 192th and 234th infantry regiments, until British troops to the south of Oudenaarde received the order to evacuate to Dunkirk on 22 May 1940 and broke contact with the Belgian front one day later.

German use


After the Battle of Belgium ended in German occupation on 28 May 1940, the Wehrmacht took over all usable T-13 vehicles that had not been sabotaged by their crews. They were hastily marked with Balkan crosses to distinguish them from enemy units. Apparently, some of these participated in the war with the remaining French army, although it is unclear how many of the T-13s got used in this way. The German designation for this vehicle was "Panzerjaeger VA 802(b)". Most of these vehicles however have very likely never left Belgium, apart from being used for scrap metal later in the war. They were mostly assigned to driver training and target practice, light support duties, airfield security, counter insurgency and possibly as part of the Atlantikwall coastal defenses. However, apart from some photographic evidence, very little is known about the German use of the T-13. A single known surviving T-13 B2 exists at the Brussels Royal Museum of the Army and Military History.