https://en.wikipedia.org/wiki/General_Dynamics_Ajax#Project_progress
Ordered in 2014, the first delivery was scheduled for 2017, while it was stated that the first British Army squadron "will be equipped by mid-2019" so that they could be deployed by the end of 2020. This was delayed due to design and testing problems. Test crews were required to wear noise cancelling headphones and be checked for hearing loss at the end of operations and the vehicles were unable to reverse over obstacles more than 20 centimetres high.
As of March 2021, the British Army had taken deliveries of the Ares variant, whilst 12 Ajax variants were going through acceptance testing. In June 2021 it was revealed that trials of Ajax variants were halted from November 2020 to March 2021 due to excessive vibration and noise, leaving crews suffering from nausea, swollen joints and tinnitus. Test crews were then limited to 105 minutes inside and 20 miles per hour (32 km/h). The excessive vibration while moving was also damaging electronic systems and preventing armament from stabilising. Suspension faults on the Ajax variant meant that its turret could not fire while moving.
The hulls were of inconsistent lengths and had non-parallel sides, which meant that the vibration problems did not manifest in a uniform manner, making it exceedingly difficult to determine if the vibration arose from a fundamental design problem or from build quality failures.
A leaked report doubted whether the Ajax Armoured Vehicle programme would be delivered on time and within budget and suggested that there was a risk that the vehicles' credibility would be questioned by troops and morale impaired. General Dynamics UK refused to comment on the report.
