Retrospective - The Tank is Dead

Introduction

No doubt this title will provoke some violent objections. The passing of the horse-drawn and horse-borne era did not occur in quiescent silence either. The demise of the tank does not imply any degradation in strength or status of armoured units; but rather a need to adapt to the products of technology. Just as the introduction of the tank to modern warfare had great impact on tactical philosophy, so will its passing. Perhaps it is more accurate to say that changes in tactics have led to the technological advances which have killed the tank as we know it.

The history of tank development is characterized by continuing conflict between armour and armament and between weight and speed. Ever since the tank was first introduced to warfare, designers have been torn between the need for a light fast tank, and a heavy invulnerable machine capable of resisting and destroying enemy tanks. Many nations have resolved the conflict by employing tanks of different sizes. Others have attempted to satisfy all needs in the one vehicle by achieving compromise on the various requirements. The disadvantages of each approach have often been dramatically demonstrated in military history.

Since World War II, a wide range of tanks have been produced, indicating that the conflicts still exist. As ‘general purpose’ tanks have been given better armour and better guns, so they have become larger and heavier. The evolution of special tank-killing tanks has generally been abandoned in recent years since it has been necessary to sacrifice too much mobility to enable them to fulfil their main purpose. Recent development and exploitation of other military equipments have given cause for some rethinking on the role and characteristics of the tank. The major characteristics of tanks and tank units in the past have been:

• Firepower.
   
• Protection.
   
• Mobility.

Other characteristics are often quoted, but are not essential to the nature of tanks. Alternative methods of achieving these main characteristics should be considered.

Firepower

The value of direct-fire, hard-hitting main armament is evident. The firepower of American and Australian tanks is being used to great benefit in support of infantry operations in Vietnam—in a type of war where many pundits said tanks would be useless. Despite the fact that the enemy have no armoured vehicles and virtually no soft-skinned vehicles, and despite the difficulty of coming to grips with enemy concentrations, the weapons of the tank have been useful. The main guns can deal effectively with enemy bunkers and their accuracy allows a commander to quickly and effectively neutralize any suspected enemy position which he can pinpoint and indicate to the tanks. Even the heavy machine-guns which are carried on most tanks provide the infantryman with a source of sustained heavy calibre firepower which is not otherwise readily available to him.

Probably one of the greatest advantages of tanks over both artillery and air support is that the tanks are usually physically close to the mobile supported unit and consequently target indication is facilitated and communications simplified. In addition, with tanks in support of infantry, response time of their fire support may be as short or shorter than that of the infantry sub-units themselves. Against an enemy with light armoured tanks or personnel carriers, or even soft-skinned vehicles, the main tank armament finds many worthwhile targets which cannot always be dealt with quickly by other means.

On the other hand, whilst the Vietnam war has illustrated some of the advantages of tanks in a situation where there was some doubt about their value, it has also demonstrated the effectiveness of other forms of direct firepower. The enemy have shown how effectively various sized rockets can be used in both direct and indirect modes. Most of these weapons are man-carried and their accuracy has been proven in combat and in tests of captured weapons. They have been used against vehicles, personnel carriers, strongposts and even tanks with devastating results. They appear to offer many of the advantages of the tank main gun with few of the disadvantages. Allied use and exploitation of similar weapons has been inhibited by the ready availability of other sources of firepower. While a commander can obtain heavy suppressive or destructive artillery or air fire support, or call on tank support for direct fire missions, the absence of other direct-fire weapons is not critical. An American weapon which has partly filled the gap created by the absence of suitable man-carried rocket-launchers is the M79 grenade launcher. This weapon has proven to be useful in a direct-fire short range role, to supplement infantry small arms weapons. 

Helicopters have proven to be a valuable source of firepower to the infantryman. Until recently, the accuracy of the fire from gunships was limited by the need for the aircraft to be moving forward rather than hovering. Since the introduction of the Hueycobra [sic] and the Cheyenne, the variety and accuracy of helicopter fire support have both increased enormously. Notwithstanding the limitations on endurance and weather capability, helicopter fire support will often be used rather than tanks.

Such modern innovations as gyroscopically stabilized sight systems and laser range finders have made it possible for lightweight missiles to be used effectively from different types of platforms. Such weapons as Swingfire and Dragon offer lethal tank-killing capability with accuracy and range in the same order as tank main weapons. The lightweight AS 12 wire-guided missile can be helicopter launched, and has the explosive effect of a 155-mm shell. The French ACRA wire-guided missile travels at supersonic speed, covering three kilometres in less than seven seconds. Investigation of the use of lasers as weapons indicates that prototypes will be available in the near future. Such developments are rapidly leading to the time when an accurate, quickly deployed, dynamic weapon system will satisfactorily be carried and operated on smaller and faster vehicles than the tank as it is known today.

Protection

The value of the protection afforded by modern tanks has been subject to question for some time. Operations in Vietnam have shown that even without the presence of enemy tanks and aircraft, allied tanks can be destroyed and disabled.

As soon as a tank is immobilised, it loses most of its advantage. Despite development of superior armour plating materials over recent years and new hull designs, it requires only one broken track for a tank to lose its mobility, limit its firepower, and compromise its protection. This is being achieved by the use of rockets and crude landmines in Vietnam. Development of modern ‘high-kill’ mines will lead to much more efficient and effective anti-tank mine warfare techniques. Though the tracks of the tank resist small-arms fire better than pneumatic tyres, the machine can be completely immobilized if the track is cut—whereas a multi-wheeled vehicle might be able to continue to operate with one wheel missing.

Despite the heavy protection afforded by tanks, the two areas most vulnerable to disabling damage are the running gear and the main armament—that is, the tank’s mobility and its firepower. The rather lavish protection of the crew of the modern tank is to no avail if mobility and/or firepower are lost.

The development of anti-tank missiles and guns, and even artillery and airborne weapons, has advanced so far that any hope of providing effective conventional armoured protection to a useful tank should be discarded. Protection from such weapons must be sought in evasion or deception, or in some new method or technique which is not yet employed. The bigger and slower the tank, the more difficult will evasion be. Concealment of a large tank from visual, infra-red or electronic surveillance is difficult. Deception is awkward and expensive with large machines—even dummy tanks being bulky and costly. These factors have led to recent consideration of light-weight tanks with high speed and manoeuvrability, where physical shielding has been sacrificed to a certain extent for increased evasive capability. The Sheridan tank for instance weighs only 16 tons and has a maximum speed of 40 mph. One of the fastest tanks in the world today is the French AMX13 which achieves a speed of 43 mph. It is conceivable that scientists of the near future will develop an anti-metallic protective shield based on magnetic or electric fields. Alternatively, a system of tactical anti-ballistic missiles might be developed for operation from land vehicles. Only a breakthrough of this magnitude would appear to offer a suitable solution to the problem of protection from modern missiles, guns, and other tank destroying ordnance. CBR protection can be provided by many materials other than armour plating and need not impose the enormous weight penalty which exists at present.

Reasonable protection against small arms weapons and shrapnel can now be achieved by use of relatively light-weight materials, which can be carried by other means apart from tanks. This type of protection is only incidental to the other characteristics of the tank, in any case.

Mobility

Tanks achieve their mobility by virtue of low ground pressure, the resistance of tracks to damage by small arms fire, adequate horse-power and suitable suspension. Restrictions on mobility are imposed by:

• Densely timbered country.
   
• Excessively rocky terrain.
   
• Wet and marshy ground. 
   
• Ravines, steps and excessively steep gradients.
   
• Damage to tracks.
   
• Artificial obstacles.

Because of lower ground pressures and invulnerability to shrapnel and small arms fire, tracked machines have generally offered better mobility than wheels. However, tracks are useless if broken; they are very prone to damage in rocky terrain, and they add to the all-up weight of a tank. The sheer size of modern tanks has contributed to limiting their mobility—particularly on highways. Although weight distribution may be kept low, most modern tanks have a bridge classification far higher than other military vehicles and this restricts their movement on highways. Highway movement of tanks can badly damage road surfaces. In some countries, railways cannot accept the weight and dimensions of tanks.

Recent work with new wheeled vehicles has indicated that far greater mobility might be practicable than was apparent a few years ago. Two of the more outstanding recent examples of such machines are the Caterpillar ‘Goer’, and Lockheed’s ‘Twister’. The former vehicle is in service in Vietnam at present in various cargo carrying configurations, and is demonstrating cross-country performance equal to that of M113 personnel carriers in swampy going. The vehicle has an articulated body with ‘wagon steering’ and four large, low-pressure tyres. There is no suspension system but the four-wheel drive will allow 30 mph movement carrying an eight-ton load. The vehicles were originally designed as logistic support vehicles for armoured and mechanized units—and as such they were required to have comparable mobility. The Goer evolved from wheeled earthmoving equipment and speed was not the main aim. Though not armour-protected at all in its present configurations, the Goer has such a respectable load carrying capacity that it could be lightly armoured with a relatively small restriction in its cargo carrying capacity. In the foreseeable future, the vehicle could probably be fitted with heavy machine-guns, rocket or missile launchers, or even cannon, to give it firepower as effective as the armament on current main battle tanks.

Twister offers even more potential for high speed mobility over rough terrain. This vehicle has a fully articulated double body, with eight driving wheels and independent suspension, and a separate engine in each part of the body. The manufacturers claim a top speed of 65 mph, a twenty-foot turning radius, and ability to traverse extremely rugged broken ground without upsetting the passengers. It has a 400-mile range, is air-transportable, and can be adapted to a wide range of configurations. Although it is not yet in military service, the United States have commissioned Lockheed to build three military prototypes for evaluation.

Ground effect machines, or hovercraft, have made a significant impact on vehicle mobility, particularly in extremely soft going. Their limitations are such that they will probably have little influence on the replacement for the tank. A combination of wheels (for control) and air-cushion (for load distribution) has been found to be a satisfactory solution to the movement of heavy loads over soft ground. However, the combat vehicle of the future will probably rely on light-weight and manoeuvrability for its mobility and speed, and will not require air-cushion for normal cross-country travel.

One of the most significant technological advances which will affect the design of future cross-country vehicles is the invention of cellular rubber tyres. These are non-inflatable tyres, of coarse grain closed-cell synthetic rubber, with inert gas filling the cells. Experiments have indicated that tyres made of this material perform satisfactorily, though they are rather more rigid than conventional tyres. At high speeds there have been some problems with overheating, but this difficulty is probably only a temporary one. Puncture tests have shown that the tyres are virtually unaffected by complete penetration by nails, spikes, and bullets. The small number of cells which are ruptured by the projectile do not affect the overall resilience or stability of the tyre. This could mean that the main objection to wheeled combat vehicles is about to be overcome.

What of the Future?

If the tank is indeed dead, what remains? There will probably continue to be a need for vehicles which can carry heavy firepower wherever it may be needed. There will still be a need for highly mobile weapon systems to move in close ground support of vehicle transported infantry. There will still be a requirement for a fast cross-country vehicle to strike at the enemy from the flank where he least expects it; to pursue the withdrawing force; and to provide concentrated but mobile firepower in the counter-attack. Even in counter-revolutionary and limited war, these needs will continue to exist. The combat vehicle of the future will not be stereotyped. It will probably be essentially an articulated vehicle with probably more than eight driving wheels fitted with cellular/solid tyres, capable of high speed performance in most types of terrain. It could have multi-fuel engines with an operating range in the order of 500 miles rather than the typical current tank range of 200 miles. The basic machine will have a low profile, and will be adaptable for use as troop carrier, cargo carrier, recovery vehicle, mortar, howitzer or field-gun platform, anti-aircraft weapon carrier, or as a direct-fire weapon carrier. In this latter role, the vehicle may be fitted with rockets or guided missiles, heavy machine-guns, grenade launchers and other novelties. Combat vehicles will be armoured against small arms fire and shrapnel, probably using lightweight alloy or plastic plates or flexible sheets. At some time in the future these vehicles may be equipped with invisible electronic or electro-magnetic anti-missile shields. Some may be equipped with electronic remote explosive initiators which will destroy enemy mines or incoming missiles or rockets at a safe distance. Science may produce a practical, self-protection, anti-ballistic missile for launching from the vehicle to deal with offensive enemy ordnance. These combat vehicles will demonstrate many of the traditional characteristics of cavalry units—even more than tanks ever did.

The tank of today is as anachronistic as mediaeval suits of armour. Though it has many obvious advantages, it has evolved to the stage of imminent extinction, because it has become increasingly inefficient in an age which demands more of machines than ever before. It has become the Juggernaut of modern military technology, demanding high capital outlay and enormous logistical support, in return for fire support not much more effective than that of the lone enemy guerilla who destroys the tank with a well-placed rocket.