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Loco issues contribute to poor Caledonian Sleeper PPM figures

Issues with new locomotives have contributed to the low PPM figures posted by Caledonian Sleeper since Serco took over the franchise, according to the operator’s performance director, writes Sam McCaffrey.

Caledonian Sleeper’s latest PPM figure, for Period 2 (3 May to 30 May 2015), is 91.7%, which is significantly lower than the 98.2% posted a year ago when the services were a part of ScotRail. However, it is an improvement on the 88.8% from April.

David Simpson, performance and safety director at Serco Caledonian Sleeper, told RTM that it’s usual for the numbers to fluctuate from period to period, especially as the franchise operates so few services.

“With all the small numbers it can only take a few small incidents to quickly knock trains beyond the PPM targets, and I think that’s what happened in Periods 1 and 2 since we took over from ScotRail,” he said.

Last period, 15 Sleeper trains missed their PPM targets, with the causes evenly split between  Network Rail issues, delays caused by other operators and Serco’s own problems.

Of the operator’s own problems, the one contributing most to missed PPM targets is issues with the new Class 92 locomotives, which haul the Mark 2 and Mark 3 British Rail coaches.

When it took over, Serco elected to move on from DB Schenker, which had been hauling the Sleeper coaches for more than a decade, and awarded the contract to GB Railfreight instead. This also meant a switch from Class 90s to GB Railfreight’s Class 92s and – from October on the non-electrified sections – a switch from Class 67s to Class 73/9s.

Under the new arrangement, refurbished Class 92 dual-voltage electric locomotives haul services south of Edinburgh and Glasgow, and failures with these have contributed to 20% of Caledonian Sleeper’s total missed PPM targets.

The problem with the locos is caused by two pieces of safety equipment meant to detect stray electrical currents and protect against their impact.

Simpson said: “The limits [for] those two pieces of kit are set quite tight, for good reason, and what we’ve found is that when the locomotives travel through neutral sections in the OLE [overhead line equipment] some of that protection has been tripping out, because it has recognised interface issues between the OLE and the loco. The procedure there is straightforward – the driver can reset the kit and travel on as normal – but that can cause delays and has and caused PPM miss at destination.”

The Class 92s were built for use through the Channel Tunnel and Serco believes that the levels at which this equipment is set is higher than is necessary for use on the main line network. The company is working with GB Railfreight at relaxing the level at which the protection is set.

“Now that has to go through Network Rail to be validated, which is absolutely right and proper, but there is a strong case for that and it should give us some additional resilience as we go forward,” Simpson said.

He added that so far in Period 3, as of 17 June, they have had no PPM failures due to the issue so it appears it may be resolved.

For more from our interview with David Simpson, performance and safety director at Serco Caledonian Sleeper, see the next issue of RTM.

(Picture by: Train Photos)

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