The Tank, Heavy Assault, A33 (Excelsior) was a British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 experimental heavy tank

Heavy tank

A heavy tank was a subset of tank that filled the heavy direct-fire role of many armies.Heavy tanks have usually been deployed to breakthrough enemy lines, though in practice have been more useful in the defensive role than in the attack...

 based on the Cromwell

Cromwell tank

Tank, Cruiser, Mk VIII, Cromwell ,The designation as the eighth Cruiser tank design, its name given for ease of reference and its General Staff specification number respectively and the related Centaur tank, were one of the most successful series of cruiser tanks fielded by Britain in the Second...

 (A27) design developed in the Second World War when there were concerns as to performance of the Churchill tank

Churchill tank

The Tank, Infantry, Mk IV was a heavy British infantry tank used in the Second World War, best known for its heavy armour, large longitudinal chassis with all-around tracks with multiple bogies, and its use as the basis of many specialist vehicles. It was one of the heaviest Allied tanks of the war...

.

Development

After the Dieppe

Dieppe Raid

The Dieppe Raid, also known as the Battle of Dieppe, Operation Rutter or later on Operation Jubilee, during the Second World War, was an Allied attack on the German-occupied port of Dieppe on the northern coast of France on 19 August 1942. The assault began at 5:00 AM and by 10:50 AM the Allied...

 raid in August 1942, there was concern that the Churchill was not as good as expected and a tank to combine the infantry

Infantry tank

The infantry tank was a concept developed by the British and French in the years leading up to World War II. Infantry tanks were tanks designed to support the infantry in the attack. To achieve this they were generally heavily armoured compared to the cruiser tanks, to allow them to operate in...

 and cruiser tank

Cruiser tank

The cruiser tank was a British tank concept of the inter-war period. This concept was the driving force behind several tank designs which saw action during the Second World War....

 roles was planned.

English Electric

English Electric

English Electric was a British industrial manufacturer. Founded in 1918, it initially specialised in industrial electric motors and transformers...

 built two prototypes on a Cromwell tank

Cromwell tank

Tank, Cruiser, Mk VIII, Cromwell ,The designation as the eighth Cruiser tank design, its name given for ease of reference and its General Staff specification number respectively and the related Centaur tank, were one of the most successful series of cruiser tanks fielded by Britain in the Second...

 hull the first with the suspension of the US M6 Heavy Tank

M6 Heavy Tank

The Heavy Tank M6 was an American heavy tank designed during World War II. The tank was produced in small numbers and never saw combat.-History and description:...

 and the second with a widened Cromwell track. The design included extra armour and an Ordnance QF 75 mm gun. With the problems of the early Churchill models worked out, the project was dropped.

Survivors

• The second pilot vehicle is on display at the Bovington Tank Museum
  Bovington Tank Museum
  The Tank Museum is a collection of armoured fighting vehicles in the United Kingdom that traces the history of the tank. With almost 300 vehicles on exhibition from 26 countries it is the second-largest collection of tanks and armoured fighting vehicles in the world.The Musée des Blindés in France...
  
   in Bovington, UK.