Increased Reliability

TfW Class 769 769008 on a test run from Rhymney to Cardiff

What do passengers and consumers demand from any Train Operating Company (TOC)? They need trains to be clean and tidy, comfortable and running on time but, above all they need the trains to be reliable so that, if a train is supposed to depart at 08.30 in order to get them to work, they must have confidence that this will happen – not just on the odd occasion, but every day. Over the years, many TOCs have fallen short in this respect, largely because of old, out of date locomotives and trains. Too often the cry has gone up that certain parts of the British rail network have suffered because the old stock has been pushed to less demanding areas but, sadly, time and time again, it has been shown that this is false economy. Looking at TfW’s current fleet, The Class 170 fleet were introduced in December 2019 and the first Class 769 in November 2020 and already both have seen huge improvements in reliability. The 175 fleet remains consistent with its reliability.

One TOC which has taken this matter seriously is Transport for Wales. A great deal of time and money has been invested in getting to the root of the problems and then endeavouring to put matters right. Not only has TfW been investing in new stock but it has also investigated ways of improving the results even more and an example of just how successful this approach is can be seen from the latest figures for reliability of the trains in the network where, for example, TfW trains are now travelling more than 2,000 miles further before they develop a fault. The increase in reliability since October 2018 means those trains can effectively travel twice round the entire Wales and Borders network before needing any sort of repair (miles per technical incident).

Transport for Wales' Head of Customer Experience and Innovation Barry Lloyd said: “Punctuality always comes top when we look at the factors affecting customer satisfaction, so it’s fantastic to see this recent improvement in performance. A fantastic achievement from all involved and one that our customers would have welcomed.”

The improvements have helped TfW to become the third-most improved TOC in Britain during that period, according to the ORR. The improvements have also been key in fleet hitting availability targets every day for more than a year. The figures have also been helped by Covid-19, which has seen fewer trains running, those customers still travelling between October and December 2020 enjoyed a 24.4% improvement in on-time performance against the previous figures in 2019.

How were these Results Achieved?

In attempting to makes these massive steps forward, there is no magic button to press. It has been necessary to look at every aspect of the way TfW’s trains operate, where necessary to work with other organisations, to look at whether there are new technical developments that can be applied, and are new working practices required? The answers to these questions make interesting reading. Barry Lloyd explains.

Joint Seasons Management Group

In 2019, Transport for Wales Rail, along

with Network Rail, established a new joint seasonal management group. Redesigned from the ground up, we implemented a new ‘risk-led’ seasonal framework which is underpinned by a robust governance structure ensuring all our mitigation plans are thoroughly validated by all departments before being deployed. This approach has been commended and is now recognised nationally as good practice.

Live Availability Targets

Every day we need to work with our train planning and performance teams to understand what our train availability requirement is – how many trains our fleet team need to deliver ready for service to meet the needs of the timetable. By understanding the needs of the business on a live basis we can be more fluid in what we deliver each day – for example when a route is out of action due to flooding or engineering works, we may need to reduce the number of trains we have to get ready, giving us more time to deliver maintenance on other trains.

Wheel Slide Protection

A piece of technology that works similarly to anti-lock brakes on a car. These were fitted on all of our Class 150 fleet (36 trains) in 2019/20. As a result, none encountered wheel flats in the autumn of 2019 or in 2020. Wheel flats occur when a metal wheel slides along the track rather than rolling, due to slippery seasonal conditions – much like aquaplaning.

The weight of the train is all on one spot of the metal wheel, causing a flat spot which must be repaired before the train can carry on in service. If left untreated they can cause serious damage to both the wheels and track by acting like a sledgehammer coming down on an anvil rather than a smooth rolling motion.

Wheel slide protection significantly reduces the chances of the train sliding in poor conditions. While it is in place in more modern trains, our Class 150 fleet were built in the 1980s before this technology was widely available. We were the first in the UK to retrofit the technology to Class 150s.

Performance Technicians

The performance technicians are a selected team of five additional people providing 24/7 cover focussed primarily on defects, defects being the cause of all problems. Every shift, the PT’s evaluate the previous days’ failures and live failures in traffic to establish what work is required, possible root causes and solutions to rectify. The performance technicians personally oversee any repeat defects that arise, building work packages specific for such faults and monitoring the train’s performance. They are the first line technical support for the technicians and have contributed to the MTIN* increase the business has seen over the last two years.

Reporting

From a reporting perspective, we have transitioned to PowerBi software, allowing us greater insights into factors such as delay trends and locations.

Wabco Compressors

This is an extremely interesting development and is one that has arisen from more detailed studies of in-siu failures.

The class 15x fleet are fitted with Cummins NT855 and L10 engines. Each engine is fitted with an engine driven air compressor to provide compressed air for the vehicle pneumatic system. Due to the configuration and design of the compressor, the vehicle pneumatic system suffers from oil contamination caused by oil carryover from within the engine driven compressor. These compressors fitted to the 15x fleet have also led to a 91% increase in air system reliability.

The carryover of engine oil from the compressor into the unit pneumatic system has contributed to the build-up of carbon being deposited in the air delivery pipe and a build-up of emulsification within the air reservoirs and filters. These issues have led to subsequent reliability problems of pneumatically operated ancillary systems such as the air dryer and door system components. The concept of the modification was for the positive inlet pressure to assist the compressor internal sealing arrangement with retaining the lubrication oil effectively, thus reducing oil carryover and subsequent contamination of the air system.

The Wabco 636 twin air compressor: • drastically reduced air system build up times as it utilises positive air feed directly from the intake manifold; • drastically reduces oil carry over compared to the Holset during trials. The Holset 676 delivers 30 CFM compared to the Wabco 636 delivering 37 CFM; • offers reduced maintenance, as there are no moving parts in the cylinder head as reed valves are used; and • reduced maintenance requirements leading to reduced whole life costs.

Results

Footnote * A measure of the engineering reliability of trains expressed as the average mileage between incidents and reported for individual fleets. A 3 Minute Delay (TIN) is counted when a fault on a train causes a total primary delay of 3 or more minutes at any point on one journey for a single root cause, where the root cause is a technical or maintenance defect on the train. This relies on a precise common definition of miles and 3 Minute Delays (TINs).