Class 707 reliability climbs upwards

Informed Sources

A fleet destined to go off-lease soon leads New Train TIN-watch

Top of the table: a brace of Class 707 units pass through the disused piers of the former East Putney – Point Pleasant Junction up line flyover while forming the 11.07 Waterloo – Waterloo circular on 14 July 2018. Antony Guppy

TIN-watch uses Moving Annual Average Miles per Technical Incident (MTIN MAA) because it smooths the ups and downs of fleet reliability from period to period, due to external vagaries. But with the South Western trains consistently topping the table – and this month over 2,000 MTIN clear of the Yardstick of Derision (the Pacer), I thought it might be of interest to record how Wimbledon depot and Siemens have got to the current reliability level.

Conveniently, all 30 five-car units were in service from Period 1 2018-19, the figures for the two previous periods looking a bit ‘cut and paste’. Note that the number of faults per period is trending downwards, over a short timescale in rolling stock reliability growth terms. But in parallel the fleet mileage has dropped.

Finally, the MTIN for the latest Period shows why MTIN MAA is my preferred yardstick for TIN-Watch and this year’s annual Golden Spanners analysis starting on page 54.

In Table 1, with the Class 700 Thameslink fleet at full strength, the drive is on to accelerate reliability growth. MTIN MAA has been inching up by 300-500 miles each period and should overtake the Golden Spanner-winning Northern Class 142 fleet next period. However a breakthrough into five-figure territory is overdue.

Also overdue are more participants. With 31 Hitachi Class 385 electric multiple-units in service with ScotRail for the start of the new timetable, I hope to add them to the table shortly.


It’s been a turbulent year on pretty well every front and next year seems set to be even bumpier. As ever, through the triumphs and disasters of 2018, the giant jigsaw puzzle which underlies this column has depended on the multitude of informed sources who have provided the missing pieces enabling me to provide readers with as comprehensive picture of what is happening – or going to happen – as possible.

So please continue to e-mail me with observations, corrections and criticisms. You can follow my, mostly, inconsequential ramblings on Twitter (@captain_deltic). If you don’t yet subscribe to my monthly blog Informed Sources e-Preview, e-mail me ( for an invitation.

But for now may I wish all readers a joyous Christmas and a happy new year.