LNER 225 sets

[D365]

Forty years has generally been standard for electric rolling stock.

Indeed but the 91s were designed for 30 years, which most/all of them reached.

 

[yorksrob]

Indeed but the 91s were designed for 30 years, which most/all of them reached.

Most rolling stock lasts longer than it was designed for. Look at the "stop gap" HST's !

 

[DanNCL]

Forty years has generally been standard for electric rolling stock.

For slower speed electrics yes, racehorses like the 91s however usually only last 30 years. Or even just half of that in Japan!

Indeed but the 91s were designed for 30 years, which most/all of them reached.

117, 120, 126 and 128 made it to 29 years in service, the rest all made it to at least 30 years in service. 101, 105, 106, 107 and 109 are now at 35 and if as speculated above last until 2027 they’ll reach 39 years in service.
108 despite being the first to be withdrawn still made it to 31 years in service.