[3] A relatively novel feature at the time was the presence of airline-style at-seat entertainment systems at some seats that enabled passengers with headphones to listen to radio and recorded audio tracks.

Various noise-dampening measures were incorporated, such as a floating floor, acoustic ceiling panels, and high levels of insulation, to produce a relatively quiet interior; a low-noise air conditioning system was also fitted.

[3] The Class 175 is furnished with a passenger information system, consisting of onboard LED display and audio announcements that communicate both the destinations and arrivals.

[3] The Class 175 fleet was initially operated by First North Western (FNW), which placed them on routes serving Birmingham New Street, Crewe and Manchester to Llandudno, Holyhead, Barrow and Windermere.

[3] Early operations of the Class 175 were troubled by low unit availability on account of reliability problems; several services were substituted for by older locomotive-hauled trains at short notice.

Their sphere of operations was promptly extended to South Wales via the Welsh Marches Line, serving destinations such as Cardiff, Swansea, Pembroke Dock, Fishguard and Milford Haven.

[29] Performed at Alstom's Widnes facility, this work saw various improved amenities being installed for passengers, such as re-covered seats, the addition of at-seat USB and electrical sockets, new carpets throughout, and various other new interior fittings; a new external livery was also applied.

[7] On 16 January 2010, unit 175103 operating the 08:30 service from Manchester Piccadilly to Milford Haven struck two cars at Moreton-on-Lugg crossing between Hereford and Leominster.

The signaller had raised the barriers in error when the train was approaching the crossing,[38] and he was arrested on suspicion of manslaughter in July 2010;[39][40] he was convicted of charges under health and safety legislation following a trial at Birmingham Crown Court in 2013, and was fined £1,750 and ordered to carry out 275 hours of community service.

[44] The train was operating the service from Milford Haven to Manchester Piccadilly and the driver of the lorry was arrested on suspicion of endangering safety.

[45] Class 175 units have caught fire in 2004 at Preston (175008), 2009 at Prestatyn, 2011 at Manchester Piccadilly, 2017 both at Shrewsbury (175109) and between Chester and Crewe, 2018 at Deganwy, and in 2019 both near Pontrilas (175107) and at Gowerton (175102).

[46][47][48][49][50][51] In February 2018, following the discovery of a number of instances of damaged wheels on Class 175 units, the entire fleet was temporarily withdrawn from service for safety checks.

All three fires were attributed to a build-up of "debris, leaf litter, and other contaminants" in the units' under-floor engine bays, a pre-existing problem for which a remediation programme was already underway at Chester Traincare Centre.

[55] Acknowledging that the three incidents in quick succession would "raise concerns", TfW Rail decided on 2 March to temporarily withdraw from service all Class 175 units that had not been through the cleaning programme.