(30 Dec 2020, 11:35 am)Storx wrote They have a spare for every 7 - 8 vehicles though or just slightly under? 

But historically, they didn't order spares when purchasing new vehicles.

GNE since the 2013/14 order year have ordered 1x spare for every 7-8 vehicles purchased give or take a small number of exceptions (B9TL acting as spare for X9/X10 when B5TLs purchased).

Having a good spare vehicle ratio of decent spares will help reliability massively.