Checking the minutia In this narrative I suspect I will use the word ’system’ several times. It’s the word the Modular S&C project team uses frequently too. This is the team most people associate with ’those tilting wagons’. Tilting wagons may be one of the most high profile bits of kit being bought by Network Rail in recent years, but they are just part of a system – the system of bringing S&C renewals from their original 54 hour instalment time right down to just 8 hours.
The team is keen to point out that they are giving the same attention to the minutia of detail involved in achieving their goal. Everything has to be considered and controlled. From the tilting wagons, of course, right down to knowing the location of a small water pipe on the site on the night. Everything has an impact on the system. The team is changing the ethos from S&C renewal being just the assembly of construction materials to it being an ’engineered product’.
25% time reduction
About a year ago we covered the original outline plan. We mentioned Early Deployment, the Mark I Modular and the last stage - the Full Modular. This month’s coverage is a review of where the programme team has got to and what lies ahead. The impression given in their new office accommodation – in the converted Power signal Box at Euston station – is that they are steadily motoring.
Stage 1 was all about improved planning. The first stage was divided into four sub-stages and they are now at about stage 3½! The result? A 25% time reduction. The big win came by taking out the contingency element – not recklessly, but with due thought and consideration taking into account the risks involved. It could have been taken out right at the start, but without understanding why it was there and without doing anything about the underlying problems, this would have been a bit foolhardy!
Parallel working
There has always been a tendency to plan and carry out track work in a purely sequential way. This may have been down to the supervisory resource and skill levels available on site. Linear railway sites depended on a commander usually only able to control one activity at a time. This has been challenged by pressing for the maximum amount of parallel working as possible – achieved through improved planning, close site supervision and repeated practising by the teams.
Work output norms have also been challenged and best practices have been spread throughout the territories via structured lesson learned workshops.
Video records
Planners are now involved closely with the ’doers’. The results of a plan are evident when the shift videos are analysed. It is important to use video as opposed to merely relying on clipboard notes. Videos are accurate and impersonal, whereas there can be arguments about what is written on a clipboard. Personalities can get in the way!
The videos are of the complete installation from a suitable vantage point. The cameras are manned throughout the work and are able to cover all the action. There is now an element of competition between the teams – and there is now an accurate bank of new norms. The teams are however actively sharing ideas and best practice.
Plug-and-play signalling equipment!
Mark 1 Modular builds on the planning and management discipline from the Early Deployment stage. It also brings new products into use including the cutting of Switch and Crossing assemblies into ’Panels’ at suppliers’ compounds, a ’Splice’ mechanism for re-joining the panels and new lifting and handling equipment for the panels and splice.
Mark I modular has the potential to cover 25% of Network Rail’s S&C workbank. The units are transported by a variety of methods. For some locations, the modules travel by road to a railhead and they are loaded flat onto Salmon wagons to travel the final part of their journey to site as out-of-gauge loads. For others the panels are offloaded adjacent to the job and picked up by crane.
In the quest to achieve consistency of product, many lessons have been learnt – some more obvious than others. The assembly bed has to be flat – steel and concrete manipulated in three dimensions are unforgiving materials – unforgiving and very heavy. Training and competence has to be consistent at both the suppliers’ yards and also the worksite – as well as at any interim stages. Handling at all of the stages has to be designed, rather than left to ad hoc arrangements.
Where possible, this means that just about every ancillary component is pre-fitted - signalling equipment, cabling, point drives. There are plans that, on later designs, the signalling equipment will be plug-and-play. Point drives will also initially be standardised on the Hydrive system for the ’full modular’ panels since this system has a smaller footprint, enabling them to fit on tilting wagons. Point heaters are also fitted at the factory. It is no longer necessary for installers to work in the fourfoot after installation.
Lessons from Toyota
All this prefabrication is derived from the programme team’s application of SMED – a technique acquired from an engineer’s own systems engineering background. SMED stands for Single Minute Exchange of Dies - not much to do with S&C renewals it would seem at first. It was a technique developed by Toyota. They had the problem of trying to cut down the time it took to change dies in their motor production lines.
By questioning what had to be done on the production line and what could be done externally, they began to make useful – and then dramatic – savings in production downtime. They went from an operation that used to take days down to one that could be done in minutes. It’s the same technique used in the Mark I modular operation and is yielding similar impressive improvements.
Designing from scratch
The full modular stage aims to reduce times further to 21 hours and finally to 8 hrs. This is where the acquisition of the tilting wagons comes in. This will allow 75% of the workbank to be given the modular treatment. Network Rail have placed an order with Kirow of Leipzig for the supply of 26 special wagons. Michael Hartmann of Kirow explained that this was a new venture for them - Kirow are usually associated with cranes.
The remit that they were given by Network Rail was that they were to draft a method of transportation for the S&C panels. They were given the W6a loading gauge, the lengths, position and weights of the bearers and asked to come up with a strategy consistent with the modular renewal programme.
They feel that their success came from starting from scratch by designing the wagon around all the required parameters. This made a big difference compared to existing designs in use in Europe. Although there is no problem with weight distribution or with wheel loads, the main technical challenge is of ride. These will be very long wagons. They need a stiff spine.
They have tested their early concept designs using VAMPIRE software at Manchester Metropolitan University. In this way they are able to simulate ride quality before the main build. VAMPIRE enables them to put together a virtual model. The first feedback from Manchester shows they have a sound design. They are now confident to proceed to final design, fabrication and final acceptance testing.
First prototype wagons
The programme’s Rail Vehicle Project Engineer, Kate Burt is liaising with Kirow and explains that there are three types of wagon and they run in fixed rakes of three with the ability to add extra units as required as shown in the illustration. Those with low drawbar connections can take longer modular sections. Those with buffer stocks restrict the loading of panels at the ends. Each wagon has its own power source. The power plants are for moving the platforms – they are not used for traction.
The wagons are at the advanced design stage at moment. This summer Kirow will start to cut steel with building in the autumn. By early 2009 the first prototype wagons will have been built. They will then undergo functional testing – the platform movements, clamps etc. Acceptance testing will take place in the UK and once this is complete the remaining sets will be constructed.
Wagons – but remember the bogies!
The details of how the panels are to be clamped to the moving frame are the subject of detailed discussions. There are thoughts that ’something different’ will be developed that takes into account the actual process involved in the job on site - using the crane, picking up the panel and laying it on the ground. There is certainly a wish to keep away from having staff working at a height struggling with individual clamps and ratchets. Therein lies danger and an activity that swallows huge amounts of time.
Whilst the wagons will deliver the units to site ready for the final lift, and whilst the order in the train formation is not critical, the train does have to be the right way round. This quirk of railway logistics has been discovered by railway engineers through the generations and most recently by Network Rail’s High Output Relaying project. They have been very helpful with this part of the operation.
Once the wagons have been tested and accepted, there will follow a programme of training and familiarisation. Systems engineering techniques will be used again to tune the operation. The programme team received sound advice from their NDS logistics colleagues, that placing the order was one thing - getting wagons delivered on time with bogies underneath was another!
There is a very high demand for bogies globally and so these components had to be ordered quickly. Fortunately, the wagons, whilst being complex functionally, do not push the frontiers of rolling stock knowledge. Both the all-up weights and the running speeds are modest - 72t and 60mph respectively. Standard low bogies are sufficient and delivery of these has been secured.
Further work
But, as was said at the start of this article, the S&C project is not just about the wagons. There is still the issue of rapid excavation of spoil, its disposal and the importation of new material and the preparation of the new track bed. In parallel with this is the issue of welding – probably using mobile flash butt welders – and the introduction of new stressing processes.
Reference was made to the accurate knowledge of site conditions. It has never been acceptable to be taken by surprise by site conditions. These must be known and managed beforehand. But this is ever more important when there is only 8 hours available. As we’re all aware, the smallest cable can cause a disproportionate amount of delay and disruption. There has to be a step change in the quality of survey work – with accurate updates to stop the surprises presented by recent site changes.
Tailpiece
So, in the coming months whilst the wagons are being built, the team will not be waiting around. There is still plenty to sort out to ensure that the system (that’s 8 times) of S&C renewal really does break the time barrier. Delivery of ’those tilting wagons’ will be just the completion of another stage.
