Purpose of this blog

Dmitry Yudo aka Overlord, jack of all trades
David Lister aka Listy, Freelancer and Volunteer

Sunday, April 5, 2020

The Biggest and Best?

The first half of the 1950's were a very interesting time for the British tank designer. They had been given an enemy armour target of 6in @60 degrees to beat. This was based on a British assessment of exactly how much penetration was required to knock out the most protected Soviet target in their arsenal (the IS-3) and cover any future stretch potential in the face of improving armour thicknesses. To achieve this, they scaled the idea up to the biggest direct fire gun they could, and designed a vehicle around it, basing the tank on the FV200 chassis. This resulted in the FV215 and its whopping 183mm L4 gun.

However, the Australian's, with assistance from the British were working on the Malkara guided anti-tank missile. This too featured a colossal HESH warhead and was capable of splattering an IS-3 across the landscape as well. Several new vehicles were designed to launch these missiles, and one was based upon the Centurion, and became the FV4010. Both vehicles filled the role of heavy tank destroyer, but with money limited, which one should the British Army buy? Major R. S. Beresford of the 13/18 Royal Hussars was asked to compare these two totally different vehicles to find out which was better.
Malkara on its launching arm.
The first thing Maj Beresford looked at was offensive capabilities. In some respects his role was made easier by the fact that any vehicle hit by either of these monstrous projectiles was just going to be outright obliterated. This meant he had no need to calculate chance of penetration, and chance of lethal behind armour effect. He assessed the chance that a hit would be a good solid hit as 78% for both, then added in a 5% chance that the Malkara would somehow be unreliable. Then came the big one, the chance of a hit.  Below 500 yards the Malkara had no chance of scoring a hit, due to the missile needing to be gathered up and brought under guidance of the operator. In comparison out to 100 yards the FV215 had a massive 98% chance of hitting the target.
From 500 to 2,000 yards, and over the Malkara had an 85% chance of a hit, while the FV215 started dropping off, reaching 59% at 2,000 yards. Adding it all together you get the following:

Next vulnerability to enemy return fire was assessed. Instantly the FV4010 has an advantage, it can be fired from a turret-down position, while the FV215 has to fire from a hull-down position. Equally with a dismounted remote controller some 200 yards away from the FV4010 the tank is further back from its firing point. However, due to armour levels if the tank is hit then the FV215 has a much better chance of survival. Another factor to take into account was the smaller size of the FV4010. In summary the FV4010 was more survivable from a static firing position, but when moving the FV215 was more survivable at close range. At longer range the chance of a miss was increased enough that the chance of being hit and killed balanced out the increased armour, but bigger size of the FV215.
Model of the test rig built to trial the FV4010 fighting arangements. Imagine the tracks and engine from a centurion sticking out the front. You can see how it would be hull down when firing.
Then cost was assessed. One would assume things would go badly for the FV4010 as it is firing expensive missiles. However, the assessment included the total running costs, this included fuel, and component life, such as wear and tear on tracks. All of the latter costs are significantly higher on heavier vehicles. Equally, the FV4010 did not have the expensive components to create a turret, such as junction boxes, turret rings and the like. The FV4010 also had one less crew than the FV215, although this was judged to be a false economy, as the support requirements for missiles would be higher. These included such things as electrical testing and checking of the missiles before being sent to launcher vehicles.

The report does give us a estimated cost of the FV4010 as £37,000, however, it fails to supply an estimated cost for the FV215 but does say that you can purchase between 1.2 to 1.6 FV4010's for the same money as a FV215. This gives us an estimated cost for the FV215 of between £44,400 to £59,200. In comparison a Centurion costs £35,000. All figures are 1953 prices, have a 25% of their cost for spares and are fully loaded with ammunition.

The FV4010 test trailer in action.
At first glance it seems that the FV215 is a far better buy, being more lethal and better survivability. However, that neglects to consider the role of the vehicle. The role is long range destruction of targets. At closer ranges, say under 500 yards, the critical distance for the FV4010, normal tank guns such as the 20-pounder would be successful against tank targets. In addition, the FV4010 would almost certainly be fighting from prepared positions, and thus be all but immune to enemy fire. With a cheaper vehicle, that performs better in its designed role, it seems an obvious choice which to select.

This concept would continue to be refined, with one of the first things to be dropped was the heavy armour and vehicle chassis, and suddenly you see something like the light ATGM carriers that feature in most armies.

Would you like to know more about the FV4010, the FV215 and the Malkara, and how they were developed, and projects that followed on? Well I have my new book out, the Dark Age of Tanks. It has a look at British armoured warfare in between about 1945-1975

It contains all the weird projects and designs I could find in the archives, and how they got boiled down to the tanks we saw in service. Of particular note was to my mind the British starting work on hover armoured vehicles!

Image credits: