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Upgrading the Jubilee line

Stewart Mills, director of operations at Tube Lines, discusses the extensive work programme comprimising the Jubilee line fleet upgrade.

Our remit is to maintain, renew and upgrade the Jubilee, Northern and Piccadilly lines on behalf of London Underground (LU). On a more strategic level, the company is working together with LU to transform the world’s oldest metro system into a railway suitable for a modern, dynamic and fast-moving capital city such as London.

Tube Lines is delivering an improvement programme worth £5.4bn over eight years to the Northern, Piccadilly and Jubilee lines, as part of an overall TfL upgrade plan for the Tube that is the largest upgrade programme that the network has ever seen.

Our remit covers a massive 41% of the entire LU network and also includes the maintenance, renewal and upgrade of over 320 kilometres of track, 254 points and crossings, 255 trains, 100 stations, 4314 bridges and other structures, 231 escalators and 110 lifts.

One of the key programmes of works we have carried out is a complete overhaul and improvement of the fl eet on the Jubilee line. This was a unique project that has set a new industry benchmark in terms of managing to implement a very complex project in record time without stopping any trains for service with a very high level of quality. Key for the delivery was the extensive use of lean manufacturing techniques, very strong quality assurance, true partnership with suppliers and very strong project management. It was imperative that this work took place in time for the Olympics due to the potential impact on availability of trains and safety.

The work packages were as follows:

Brake actuator

The brake actuator is critical to safety and availability as any leakage could activate the brakes suddenly. The process to remove and refi t a single actuator was initially eight hours and was reduced to three hours by completely reworking the process. New lifting equipment was designed by the team and that allowed the reduced process time with improved safety of the task. A team of 11 people worked on this activity mainly during nights replacing a train’s worth of brake actuators (16).

Doors

Prior to introduction of Transmission Based Train Control (TBTC), this system was already the worst performing, with large numbers of no fault found. With the introduction of TBTC and the cross-loading during the Olympics, the situation was very likely to become much worse. One of the life expired components (the EP valve) was safety critical.

Following a condition assessment of the components, the scope was defi ned and split into three phases, with the two most critical completed (phase 1a and 1b) before the Olympics.

The previous benchmark project for doors overhaul was the Northern line, where the processes were optimised, and this meant that it was possible to complete one unit (three cars) between peaks, which was already a vast improvement on the usual time taken of two days. During this project we delivered one train (seven cars) between peaks – therefore a 133% improvement on effi ciency without affecting availability of trains. This was combined with the six monthly exam also completed on the train at the same time.

A team of 41 people were working on this job, mainly during day shifts. This was also complemented by the maintenance team performing the six monthly exam.

Semi-permanent couplers

Drawgear collapse and worn-out AMPEP bearing were the two failure modes experienced by the semi-permanent coupler.

Even with relatively low numbers of failures, due to the complexity of the task of removing and refi tting, any failure would lead to trains being taken out of service. The combination of the overhaul being overdue and the duty cycle as a result of TBTC were making the situation diffi cult to manage with part of the overhaul being overdue and hardest duty cycle with TBTC. The initial strategy of just replacing the AMPEP bearing, although this was having a positive effect, was not enough and a full overhaul of the coupler was required.

The process for remove and refi t was created from scratch to ensure the task could be performed between peaks at the takt rate of one train a day.

Previously a single replacement of a semipermanent coupler used to take over 12 hours. Critical to the process was a bespoke lifting table/stillage, which was designed for the completion of this task. This allowed the team to remove the whole assembly in one stage. This lifting table was also used to transport the semi-permanent coupler to the sub-supplier for overhaul, thus improving the safety of the transportation process.

The supplier for the overhaul of this system had never performed a task with this level of intensity and it was subjected to a very comprehensive audit regime by Tube Lines to ensure the quality of the product was not compromised. The number of team members that worked on this project was 27.

Saloon seats

Previously, the seats on the Jubilee line fl eet were a traditional sprung wire construction comprising of coil springs and a wire frame.

A feature of this type of construction is that when a spring fails, there is a possibility of a sharp wire protruding from the seat base and causing damage to property or injury to passengers. This was an increasing situation with the seats on the fl eet and they were deemed fundamentally life expired.

There were two options for replacement of these seats: direct replacement with new versions of the existing design or a new design to remove the historical failure modes and, if possible, provide a reduced whole life cost model.

After a tender process for a new design a supplier was selected. The new seat design had a customer satisfaction survey with over 700 interviews and a satisfaction rate of over 90% of customers.

The seat achieved compliance with London Underground’s customer satisfaction ratings and met or exceeded the performance of the existing seat design in every respect, whilst offering a cost reduction and improved whole life cost model over the existing design.

Although the original assumption was to keep the moquette and replace only the seat bases due to the tight timescales for completing this programme of works. However, at the end of 2011, the executive team authorised the replacement of the moquette and it was decided to fit ‘Landmark’ moquette to the seat bases, backs and the perch seats.

However a tolerance issue was identified during the fitment of the first train. Therefore the design was revised and the works to replace seat covers was completed ahead of schedule in July 2012. The team of 33 members were working mainly during days, on the same train as the doors completing the tasks between peaks. Drivers’ seats were also replaced, with new L17 seats replacing the existing L14 design.

Small wheels

A programme of replacement of small wheels has been running on the Jubilee line fleet for a number of years. This programme was necessary for a number of reasons. During the early life of the fleet there were less than perfect wheel turning regimes in place that needlessly turned wheels and as such reduced the fleet mean wheel size and a delay in commencement of the nine-year overhaul as originally planned. The fleet issued a concession to allow the minimum Motor Wheel Set size to reduce from 710.00 to 707.00 mm.

This programme had been in place for around two years when the Fleet Improvement Team took ownership and the programme had delivered just over 200 motor wheel sets into the fleet at an inconsistent rate of four wheel sets a week. In order to meet the predictor demand, and prevent multiple units from being stopped for small wheels prior to the Olympics or during the Olympic period, 300 wheel sets had to go through the small wheel programme between January 2012 and the start of the Olympics and in order to achieve that the weekly takt rate had to be increased from four to eight then 12, 16 and 20 for the final weeks before the Olympics.

When the fleet improvement team took this project, the following road blocks were preventing tark rate from even achieving the rate of four sets a week:

• Surety of supply for consumed materials, some of it with 50 weeks lead time.

• Labour for removing and refitting the wheel sets (depot activity).

• Capacity at LH Group Wheel Sets (the main contractor).

• Float of wheel sets (wheels available to support takt rate).

The above challenges were successfully overcome by:

• Tube Lines personnel seconded to LH to ensure close coordination with depot to ensure slick supply and return of components; this also allowed the removal of bottlenecks at processes at LH and improvements from the quality point of view.

• Required quantities of material were gathered by identifying and validating alternative suppliers, strong negotiation of lead times and approaching other rail companies who had material in stock for their usage borrowing it.

• Reverse engineering of some of the castings from rapid prototyping.

• Integration of the ‘lifting team’ with the pull forward team and membership increased from four to six with the teams from other pull forward activities supporting on an adhoc basis.

• Daily review with fleet planners, LH and overhaul team to ensure right trains were already with right wheel removed when they arrived from supplier. Any changes in plans were communicated on real time.

In addition to the above, the overhaul team was working very closely as a single team with operations and supporting it when required. Towards the end of the reliability programme the team supported the implementation of some of the reliability activities such as PEA covers, windscreen wiper replacement, headlight bulb replacement, under frame security checks and floor coving. During the Olympic period, the members of the team who were to be retained for the remainder of the overhaul and phase 2 of the doors became part of fleet operations to support the activities during the Olympic Games. This ensured there was continuity and the knowledge and experience gained during the Games was not lost.

Activities at REW

REW was the nominated supplier for the Jubilee line overhaul. Although the activities at REW had very limited impact on the performance of the fleet, they are worth mentioning due to the innovative approach taken to manage REW.

A Tube Lines team was embedded within the REW at their premises, to focus on and help deliver the quality demands for the Jubilee line. Acting as on-site representatives for the fleet team, a collaborative approach was undertaken.

The first major overhaul was uncharted territory for the Jubilee fleet as it had never been attempted before. The pre-existing documentation prepared by the original lead manufacturer was limited at best. The overhaul processes had to be built from scratch in some cases, drawing upon REW overhaul knowledge of other fleets, clarifications from the original manufacturer’s and then backed up by Tube Lines product engineers. The processes were then fully documented with a view to providing a legacy for future overhauls.

The fleet improvement team seconded at REW has been working with the REW team as a single team to ensure the quality of the product was at the right level with the following milestones being implemented for each work package:

• PFMEA of the overhaul process behind each product.

• First Article Inspection of each product.

• Quality audits of the main suppliers.

As a result of the above, the quality of the product supplied by REW (50% of the brake actuators, eight bogies and four wheel sets) have been higher than in the past and any issues are being ironed out for ramp up of bogie replacement.

Quality Assurance Activities

This year there has been a large increase in the activities of the Quality Assurance Team, which has extended its remit to all fl eets, not just the Piccadilly line fleet. Some of the key achievements have been the following:

• Number of supplier audits for the year 2012 will be 38, which is a 110% increase on the 18 audits performed during 2011. All the CARs raised have been closed on time with challenging lead times to ensure close control of the number of CARs in the system.

• Scope of activities expanded from Piccadilly to Jubilee, Jubilee overhaul, Piccadilly life extension procurement activities and Transplant.

• Closure of all the relevant CARs related to the rail grinder incident and BSI audit at TransPlant (TransPlant is a part of Tube Lines and provides specialist engineering trains and on-track plant, purpose-built to work anywhere on the LU network, and supports both Tube Lines’ and LU’s maintenance and renewal obligations).

Tube Lines is an asset management company and is a wholly-owned subsidiary of Transport for London (TfL).

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