Wan Cheng 2/萬乘二

Republic of China (Taiwan) (1975)
Fire Support Vehicle – 1 Prototype Built

The Republic of China (中華民國), exiled in Taiwan, was a key US ally in East Asia during the Cold War. Following the defeat in mainland China and Hainan during the Chinese Civil War, the Kuomintang political party and Republic of China were able to hold out in Taiwan. With mainland China now part of the People’s Republic of China (中华人民共和国), the preservation of this strategic ally in the region meant that the Republic of China would receive large deliveries of American surplus equipment to build up the ROCA (中華民國陸軍/ Republic of China Army) and prevent a potential invasion attempt by the PLA (中国人民解放军/ People’s Liberation Army). Despite international setbacks, such as the international recognition of the PRC and exclusion of the ROC from the UN in October 1971, the republic remained a staunch US ally. From the mid-1970s onward, serious attempts at creating armored fighting vehicles would be started within Taiwan, likely due to the fear of weapons becoming more difficult to import due to the warming up of PRC-US relations. These attempts generally started by combining parts of different American vehicles. One of these would be the Wan Cheng 2 (萬乘二), combining a modified M113A1 hull with an M24 turret.

The ROC’s Imports of American Vehicles

Prior to the defeat and conclusion of most of the Chinese Civil War with the fall of mainland China and Hainan in 1949-1950, the Republic of China had already taken large deliveries of US equipment, notably due to the Second World War.

The first deliveries of American tanks to the now exiled ROC appear to have started with a batch of 25 second-hand M24 Chaffees in 1951, which marked the start of the light tank’s career in Taiwan. In the following years, the Republic of China Army would receive large numbers of M41 light tanks, with 550 second-hand vehicles ordered in 1953, which would be delivered from 1955 to 1959, and later be joined with a further 150 vehicles delivered in the late 1960s. Despite these deliveries of more modern light tanks, the ROCA also received more deliveries of light US armor dated from the Second World War, with a further 275 M24 Chaffees delivered in 1957-1959, as well as 400 M18 Hellcats.

As for armored personnel carriers, the ROCA would be within the large numbers of operators of the ubiquitous American M113 armored personnel carrier, purchasing 146 M113A1s in the late 1960s (which would be joined by 267 vehicles of the M113A2 variant in the 1980s, years after the Wan Cheng program was finished). In terms of heavier armor, the ROCA would only receive the first M48A1s in 1973, meaning it had to largely rely on lighter US Armor. After they were received, the M48A1s would form the base of heavier armored fighting vehicles developed in Taiwan in the same way lighter vehicles development would start with the M18, M24, M41 and M113.

The Wan Cheng Program

Though local field conversions had existed in the past, including prior to the Republic of China’s exile to Taiwan, local armored fighting development was kickstarted in 1975 by the Republic of China Joint Logistics Command (聯合後勤司令部). This department was in charge of engineering projects since the military engineering bureau of the ROC Ministry of National Defence (中華民國國防部) had been re-attached to it in 1968. This kickstart in activity was likely caused by the appointment of a new commander of the Joint Logistics Command, general Lu Youlun (羅友倫), on April 4th, 1975. Another general of the ROCA, You Shieshi (游傑士), is known to have been involved in military vehicle projects of the era, such as the Wan Cheng. He appears to have been Major Director of the Army Ordnance Development Center (陸軍兵工整備發展中心). This service includes the Armored Vehicles Development Center (戰甲車發展中心), which is the main organisation creating the ROCA’s armored vehicles. As such, You Shieshi was likely more hands-on with the project in comparison to Youlun.

The local development which would be undertaken from 1975 onward largely started with programs to overhaul or combine elements of American armored fighting vehicles to provide more useful platforms. The most well-known example of a vehicle from this era likely is the Type 64 light tank, combining the turret of an M18 Hellcat, of which the hull was likely very worn out and used up by this point, with the hull of an M42 Duster. Other early forms of indigenous armored fighting vehicle developments within Taiwan include the Type 65 light tank, an attempt to locally produce a copy of the M41 Walker Bulldog, and the diverse Wan Cheng program.

Wan Cheng (萬乘) is an old fashioned literary term which refers to the “Army of Ten Thousand Chariots’. This was a reference to the massive army and power of the Chinese Emperor in comparison to neighboring rulers in ancient China, who were said to rather have “Armies of a Thousand Chariots”. This type of references to old Chinese literature is quite common in the Republic of China.

The program consisted in armored fighting vehicles designs which were created on the base of American armored fighting vehicles, modified in order to improve their capacities or make them able to fulfill different roles on the battlefield. Wan Cheng 1 was an M113 modified to be a 120 mm mortar carrier; Wan Cheng 3 was an M113 modified to carry the indigenous Kung Feng IV (Bee Sting) 126 mm rocket (工蜂四型多管火箭), with two launchers of 20 tubes. Wan Cheng 4 was an attempt at modifying an M48A1 to M48A5 standard, with a 105 mm gun and a variety of other upgrades, though it was far from identical to the American-made M48A5 which the ROCA also operates.

The Wan Cheng 2: The ROCA’s M113 Fire-Support Vehicle

The Wan Cheng 2 was another M113A1-based vehicle.

The vehicle can be summarily described as a modified M113A1 hull which was given the turret of an M24 light tank. This may appear an unlikely combination at first sight, but looking further, there are several reasons why such an upgrade may have interested the ROCA. The M24 Chaffee was, by this point, an aging tank, and the hulls in service with the ROCA were likely increasingly worn out and thus harder to maintain, but the turrets may still have been fully functional, and their armament, while obviously not up to the comparison with that of a modern tank, could still provide useful fire-support. Providing fire support on the widely-used M113 hull could be an useful tool to add means of mobile fire-support for M113-based units. Conversions created due to somewhat similar situations or needs have existed in other nations. During the Algerian War, France did fit turrets of mechanically worn out M24s to new AMX-13 hulls to retain their fire-support utility, creating the AMX-US light tank, while Australia would create the M113 Fire Support Vehicle (FSV) by combining the 76 mm-armed turret of the Saladin armored car to the M113A1 hull in the mid-1960s, with the vehicle being used in Vietnam. In the 1970s, at the same time as the ROCA was studying the Wan Cheng vehicles, Australia would double down with the M113A1 Medium Reconnaissance Vehicle (MRV), which used the more modern but similarly-armed turret of the Scorpion light tank on the M113A1 hull. The Australian vehicles are only some of the more professional M113 conversions, and over the years and continents, many different proposals and conversions have popped up to make the M113 hull able to perform fire support duties.

The M113A1 Hull and Modifications

The base M113A1 vehicle is an American armored personnel carrier which is best described as a welded aluminum box, with the shape designed to allow amphibious capacities, with movement in water assured by the movements of the track and no propeller or hydrojet system being present. The engine is installed on the front-right. The original M113 had a gasoline engine, but this had been supplanted by a diesel engine on the M113A1. This was the Detroit-Diesel 6V-53, producing 215 hp at 2,800 rotations per minute. The vehicle had a crew of two, a driver and a commander, who could operate a pintle-mounted M2HB .50 caliber machine gun, and the rear infantry compartment had space for 11 dismounts. Weight of the vehicle could differ from about 10 to 14 tonnes from the entirely empty to the maximum weight, with the standard combat weight being of about 12.3 tonnes.

The Wan Cheng 2’s hull was far from unmodified, with the ROCA’s engineers undertaking significant efforts to make the hull more adapted for a fire support vehicle.

The turret was to be mounted centrally on the vehicle. As such, the front-right mounting of the engine could not be retained, as the engine block would be directly below part of the turret ring. Therefore, the engine was moved to the rear of the Wan Cheng 2’s hull. Following this change in configuration, all the center and front of the hull was lowered, with only the rear of the Wan Cheng 2 hull, around where the engine was located, retaining the original height. The length of 4.86 m and width of 2.68 m were kept. This lowering, as well as the removal of the elements from the dismount compartment likely led to the Wan Cheng 2 hull being lightened by a non-negligible amount in comparison to a base M113A1. This would obviously be more than compensated once the turret was fitted. The armor layout was, in all likelihood, identical to the M113A1 for the hull. It was constructed using H32 rolled aluminum armor, with a thickness of 38 mm angled to 45° (upper front plate) or 30° (lower front plate) from the vertical at the front, 38 mm at the roof, 38 mm at 8 to 9° at the rear, 44.5 mm on the upper sides, 31.8 mm on the lower sides, and 28.6 mm on the floor.

With the engine being placed to the rear, the rear ramp was obviously no longer usable to exit or enter the vehicle, and the Wan Cheng 2 would have to be exited through different means. The hatch of the driver, to the front left, was retained, while the turret crew would likely enter and exit through the turret hatches already present on the M24 turret. The front removable cover for access of the engine was still present on the Wan Cheng 2, being pretty much a structural element of the M113A1’s hull construction, but it is unlikely that it would ever be used in anything but maintenance. On this cover, a rectangular sign was placed, with the characters 車試 (Che shi) written in white on red background. On this sign, they were likely to be read from right to left, where they describe an experimental, test or prototype vehicle.

The M24 Turret

On this modified M113A1 hull, the Wan Cheng 2 vehicle mounted a turret taken straight from an M24 light tank.

This turret used a 1,500 mm turret ring, which fit handily on the wide hull of the M113A1 armored personnel carrier. The turret was mounted centrally so as to allow for the driver’s hatch to be retained, while the turret would still sit in front of the higher rear part of the hull. The turret and its gun appear to still have been high enough that the turret could be able to rotate 360°, though there would be little to no gun depression over the rear arc.

The M24 Chaffee turret featured a three-men crew, with the gunner sitting to the left front, the commander behind him, and the loader to the right. The turret featured a large cupola for the commander to the left, and just to its right, a fairly large turret door/hatch. The gunner had no dedicated hatch to exit the turret.

Armor protection for this turret was 38 mm of cast armor to the front, with the cast mantlet also being 38 mm thick. The sides were 25 mm thick, angled at 25° on the right side and 20° on the left. The rear was 25 mm thick, with no angle from the vertical. The roof was 13 mm thick. These figures may seem deceptively similar or even thinner than the hull armor, but this was homogenous steel, which had heavier resistance in comparison to H32 aluminum – though it would also be considerably heavier for the same area and thickness. The turret was electrically rotated, with a turret motor installed towards the front of the turret basket.

The main armament of this turret was the 75 mm M6 gun, which was a lightened version of the M3 used in the M4 Sherman, with about identical performances. This gun could fire the M48 high-explosive round, containing an explosive charge of 680 grams of TNT, at a muzzle velocity of 625 m/s. This was still a quite capable weapon in the fire-support role, which would have deadly potential against recently landed troops which had not yet had the time to dig in deeply. Against armored targets, the gun could fire the M61 and M72 armor-piercing rounds. Both were fired at 618 m/s. Against rolled homogeneous armor, the M72 would penetrate 102 mm at 100 m, 99 mm at 250 m, 95 mm at 500 m and still 86 mm at 1,000 m, at 0° from the vertical. At the same ranges, the M72 could penetrate 190, 102, 92 and 76 mm, being more effective at close range but less at medium ranges and further. These values may seem very low for the 1970s – and if compared to a modern main battle tank, they certainly were – but it should be taken into account that, in case of a landing attempt by the PRC against Taiwan in the 1970s, the first waves’ armored vehicle fleets would overwhelmingly consist of lightly armored amphibious vehicles, such as the Type 63 light tank and Type 63A armored personnel carriers. The PRC was yet to have means to easily send over any significant quantity of heavier armored fighting vehicles in the first waves of an assault, and even the old 75 mm M6 would go through the armor of light amphibious vehicles without difficulty at any combat range.

The ROCA did not appear to undertake any deep internal modification on the M24 turret, but did modify the external machine gun mount. On the original M24 turret, an M2HB .50 cal machine gun could be installed on the turret basket. It was meant to be used by a crewman standing on the engine deck for anti-air purposes. This configuration did not allow for the commander or loader to use it from his hatch, which was generally disliked by crews. On the Wan Cheng 2, the .50 cal machine gun mount was brought forward, in front of the cupola, which would highly improve the machine gun versatility and its ability to be used upon short notice, particularly against ground targets. It appears that the basket mount was not eliminated, but instead, curiously enough, appears to have been recycled to mount a 30-06 M1919A4 rifle-caliber machine gun. These machine guns were not systematically installed, and indeed, most photos of the Wan Cheng 2 show the vehicle without any.

Performances and Trials

Though many points can be guessed by the features of the M113A1 and M24, the exact specifics of the Wan Cheng 2 are not known, and for example the weight or maximum speed of the vehicle are anyone’s guess. The vehicle very likely had a crew of 4, with a driver in the hull, and a commander, a gunner, and a loader in the turret. Some considerable space would likely still be available inside the hull. The vehicle’s ammunition stowage is unknown but likely had the potential to be significant if the ROCA desired so.

The vehicle underwent some mobility and firing trials. During these, it was found that the vehicle could no longer be expected to be fully amphibious. This was likely a consequence of the vehicle being made heavier by the M24 turret – guessing the exact weight of the Wan Cheng 2 is not possible due to the changes which were made to the hull as well as the addition of the turret, but a weight of at least around 14-15 tonnes should likely be expected – as well as the changes in the center of buoyancy.

The Wan Cheng 2 was never adopted by the ROCA. A reason behind this lack of adoption could be that, by the 1970s, the number of M113A1s present in Taiwan was still moderate. As such, consuming part of the fleet in such a conversion, which unlike simpler conversions such as installing mortar or rocket armament, implied some extensive transformations of the hull that in all probability could not be reverted, was viewed as an uncertain venture. This was likely supported by the idea that the combat value of such a vehicle going into the future would be increasingly uncertain.

Conclusion – An Interesting Piece in the Start of Armored Vehicles Production in Taiwan

The Wan Cheng 2 is likely the instance of the Wan Cheng program that has been seen the most by Western armored vehicles enthusiasts, though many do not even know its name and merely consider the vehicle to be an odd M113-M24 Frankenstein’s monster from the Republic of China. In practice, the vehicle was integrated in a whole series of early armored vehicles development starting in the mid-1970s.

These 1970s developments were far from entirely irrelevant. The similarly-dated Type 64 has entered service. Within the Wan Cheng program,the Wan Cheng 1 mortar carrier would evolve into the CM-22, which is still used operationally to this day, and work performed on the Wan Cheng 3 at least led to similar rocket launchers being mounted on some M113s. More significantly, the experience gained on these first attempts to modify American-designed M113s, but also M48s with the Wan Cheng 4, allowed for ROCA engineers to begin gaining experience, which they are known to have used further. The M113-based but modified CM-21 armored personnel carrier reached the prototype stage in 1979, and more than a thousand have been pressed into service since 1982. In the field of tanks, the CM-11 and CM-12, based on American technology from the M48s, M60s and even from the M1 Abrams, have been in ROCA service since around 1990.

Wan Cheng 2/萬乘二 Specifications
Length	4.86 m
Width	2.68 m
Weight	Likely around ~15 tonnes
Engine	Detroit-Diesel 6V-53 six-cylinders engine producing 215 hp at 2,800 rpm
Suspension	Torsion bars
Maximum speed (road)	Likely around 60 km/h
Crew	Likely 4 (Driver, commander, loader, gunner)
Main gun	75 mm M6
Secondary armament	Pintle-mounted (front of commander cupola) M2HB .50 cal machine gun Pintle-mounted (turret basket) .30 cal M1919A4 machine gun Coaxial .30 cal M1919A4 machine gun
Hull armor	H32 rolled aluminum armor 38 mm at 45° (upper front plate) 38 mm at 30° (lower front plate) 38 mm at 0° (roof) 38° at 8/9° (rear) 44.5 mm (upper sides) 31.8 mm (lower sides) 28.6 mm
Turret armor	Cast and welded steel homogeneous armor 38 mm (front and mantlet) 25 mm (sides and rear) 13 mm (roof)
Numbers made	1

Sources

SIPRI Arms Transfer database
STUART, A History of the American Light Tank, Volume 1, R.P. Hunnicutt
http://afvdb.50megs.com/usa/m24chaffee.html
http://afvdb.50megs.com/usa/m113.html
Blogxuite.net:
You Shieshi: https://blog.xuite.net/genliudinghan/twblog/587445282
Lu Youlun: https://blog.xuite.net/genliudinghan/twblog/294174211
https://read01.com/zh-tw/O3Lnxon.html#.YVR9AbgzbIU