The Daily Mail recently posted an article on the WWI era Mark II tank identified at tank 785.  This tank currently resides at the Tank Museum at Bovington.  According to the article, this tank was unwittingly sent into combat despite being built not out of armor plate but of untreated steel, leaving it vulnerable to rifle fire.

British tank crews unwittingly went into the first ever major tank battle in vulnerable unarmoured vehicles, historians have revealed 100 years after the event.  Researchers have found that the 45 Mark II tanks that went into action at the Battle of Arras in May 1917 were training vehicles which had no armour.  Experts believe the crews were not informed the steel the tanks were made from was untreated and therefore could be penetrated by rifle fire.  The weakness of the vehicles actually ended up helping the British war effort after one was captured by the Germans, who then abandoned plans to develop more advanced armour-piercing weapons.  But it was actually mechanical issues that proved the most costly, with just 11 of the tanks eventually crossing No Man’s Land due to breakdowns.

Read the full Daily Mail piece here