Here we are again at Bovington...
...to take a close look at another...
...intriguing sidetrack in tank development...
...the Tortoise.
It really marked the end of the line...
...for the British philosophy...
...of having two classes of tank:...
...Infantry (heavily armoured and slow...
... for supporting infantry in attacks)...
...and Cruiser (faster and more mobile...
...for exploiting any breakthroughs...
...their lumbering colleagues achieved).
In early 1943...
...with minds moving towards the eventual...
...invasion and liberation of...
...continental Europe, people started...
...thinking about the battle conditions...
...they would face.
The German skill in defence...
...had been made clear in two wars by now...
...and this reinforced a certain view...
...in the British military establishment...
...that something very well armoured...
...and armed would be needed to breach...
...the expected strong lines.
At the time, the standard infantry tank...
...then in service was the Churchill...
...but it had problems...
...an unreliable engine and...
...poor track performance...
...to name just two.
So, they started looking around...
...for other suitable candidates. First...
...a development on the Cromwell chassis...
...was considered - the A33 Excelsior.
On paper it offered little improvement...
...over the Churchill...
...and when the latter was modified...
...the Excelsior project was dropped.
Another was the A38 Valiant.
This was conceived with the fighting...
...in the Far East in mind.
Based on the Valentine chassis...
...it was hopelessly compromised...
...from the start.
It had to be both heavily armoured...
...and light in weight.
For once, and hopefully having learned...
...their lesson, they started with...
...a clean sheet of paper...
...and a specification was issued in April 1943...
...for what was described as...
...'a super heavy assault tank. '
Between then and February 1944...
...18 separate designs were produced...
...each larger and heavier...
...than the one before.
In February the Tank Board confirmed...
...a design and ordered 25 straight away...
...as the A39...
...without any prototype testing.
But the end of the war came...
...before the Tortoise was ready...
...and the order was cut...
...with just six examples being produced.
One went to Germany in 1948 for testing...
...when the impracticality of its sheer bulk...
...became all too clear.
Transporting it was a real nightmare.
At 80 tons, there was barely a bridge...
(and certainly not the...
...British Army Bailey Bridge)...
...which could take it.
However...
...unlike its predecessors...
...it was mechanically reliable...
...and a good, stable gun platform.
The first thing to notice...
...is that it looks more...
... like a contemporary tank...
...or tank destroyer than the TOG.
It rather resembles a StuG on steroids...
or a distant cousin of the Soviet SU-122
It has a double torsion bar suspension...
...(like the Tiger II)...
...and underneath it all is a 650hp...
...Rolls Royce Meteor engine...
...a detuned version of the famous...
...Merlin engine fitted to planes...
...like the Spitfire.
This could however only manage to...
...to propel the Tortoise at a maximum speed of...
...19km/h on the road...
...and 6 km/h across country...
...on tracks that were nearly a meter wide.
It has armour of between 178...
...and 228 mm on the superstructure...
...with more on the gun mantlet.
The whole of the superstructure...
...is a single massive casting.
It stands 3 metres high...
...about the same as a Tiger II...
...and over 25 cm taller...
...than an IS-2 of the same period.
This was the 32 pounder...
...developed originally....
...from the 3.7 inch anti aircraft gun.
It fired a 14.5 kilo armour piercing shell...
...at a muzzle velocity of 880 m/sec.
In tests it proved it could knock out...
...all the late war German tanks.
It certainly would also have handled...
...the IS series of Soviet tanks.
Secondary armament...
...consisted of three 7.92mm BESA machine guns...
...one in the front...
...and two in a sort of small turret on top.
Let's have a look at the ammunition...
...that was used on the Tortoise.
Now of course the 32 pounder ammunition...
...and the first thing we have...
...is the 32 pounder shell...
...two part ammunition...
...so the second part is the charge...
...and look at the size of this.
We have now moved up...
...into the fighting compartment...
...of the Tortoise.
Now the first thing that is...
...blatantly apparent is the sheer size...
...that is absolutely unbelievable.
But of course it did have a crew of seven.
So it needs plenty of room.
Let's have a look at that crew...
...in each of its individual positions.
Now the first position...
...where I am sat at the moment...
...is where the crew commander would sit.
Directly to the front left...
...left is where the machine gun operator is...
...and just to the right of him...
...you'd find the gunner's position.
You could see the gunner's seat...
...directly in front of that...
...traverse hand wheel and just above that...
...the traverse indicator.
You then have two loader's positions...
...one located to the left...
...and one located to the right...
...to the breach of the main armament.
Everywhere you look around there is...
actually ammunition stowage. Don't forget...
...Tortoise had two part ammunition.
We then move across...
...to the second of our...
...machine gun operator's positions.
And the final crew position for the Tortoise...
...located to the front right...
...was the driver's position.
The commander's position has absolutely...
...loads of room, especially compared to...
...modern main battle tanks.
Some of the key things he's got in here...
...you can see that he's got...
...a traverse hand wheel...
...it enabled the commander's cupola to rotate...
...and it's actually got a fairly good array...
...of periscopes, all the way around...
...so he did not have the bad view...
...whatsoever when he was fully closed down.
And also directly to the front right...
...to the commander you'd also see another...
...traverse indicator, a good way...
...he could actually align the gunner...
...if he had observed something first.
So...
...as far as the British Army was concerned...
...this really was the end of the road for...
...'super heavy breakthrough tanks'.
Even if, as in this case...
...they could be made reliable...
...and given a good gun...
...their sheer size and weight had to...
...call into question their value...
...on the battlefield.
Simply getting them there...
...would have been a huge headache.
And by this time...
...what we now know...
...as the Main Battle Tank...
...had started to emerge in the...
...form of the British Centurion...
....with the very good 20 pounder gun...
...and the 105 mm which was not far behind.
No longer did tanks have to be...
...artificially restricted...
...down to the pace of the walking soldier...
...since infantrymen...
...were now being carried in APCs.
The Tortoise remains a testimony...
...to the persistence of an outdated belief...
...and the tenacity of the individuals...
...who held it.