I visited Euston Friday evening / Saturday morning and noted:
Friday
On the Highlander – 92033, (Inverness), 153xx, 15330, 15331, 15332, 15314, 15205, 15105, 15006, 15206, (Fort William), 15304, 15303, 15307, (Aberdeen), 15308, 15201, 15101, 15004, with 92038 on ECS.
On the Lowlander – 92038, (Glasgow), 15209, 15329, 15325, 15324, 15316, 15203, 15106, 15008, (Edinburgh) 153xx 15309, 15319, 15320, 15318, 15204, 15108, 15009, with 92010 on ECS.
Saturday
On the Highlander – 92018, 15010, 15107, 15210, 15334, 15305, 15327, 15335, 15315, 15003, 15109, 15007, 15323, 15321, 15317, 15310, 152xx.
On the Lowlander – 92028, 15002, 15110, 15212, 15339, 15326, 153xx, 153xx, 15211, 15005, 15103. 15202, 15311, 15312, 15313, 15322, 15306, with 92010 on ECS.
Does anyone know how frequently the formations change? Do CS try to rotate coached regularly, eg to ensure all carriages have roughly equivalent mileages to simplify maintenance schedules, or are changes made on more of an ad hoc basis? TIA