How much should it cost to maintain the railway? This question is exercising the industry and government in the current Periodic Review which will determine the level public funding for the railways over next five years.

SKM have been assisting Network Rail with their work on strategic asset management. The rail engineer talked to Sam Luke, SKM’s technical director for rail and bridges, to find out about the scientific basis behind the headline numbers.

This section of SKM’s business was formed by the acquisition of Mouchel’s rail engineering assets in October 2011. We report on the group’s capabilities in advanced composites, research and development and multi-disciplinary design, and how this fits with SKM’s global operations.

Global business

Sinclair Knight Merz has its origins in Australia where it retains a strong base. Since being formed in 1964, it has grown steadily and now operates worldwide. With over 6,500 staff at 40 offices, SKM’s total revenues increased by 10% in 2010/11 to 1.2 billion Australian dollars or around £780 million.

Over 65 mergers and acquisitions in the last 15 years have given SKM its current position as a leading projects firm with global capability in strategic consulting, engineering and project delivery.

The Mouchel rail engineering business was one such takeover. Another familiar name in the UK is Colin Buchanan and Partners, which merged with SKM in June 2011.

Professor Sam Luke is SKM’s technical director for rail and bridges. Luke was one of the four senior team directors responsible for integrating the Mouchel team into SKM.

He says, “The transfer went smoothly. We have co-located all our staff, so now former Mouchel, Colin Buchanan and SKM staff sit together as one team in our office at London Bridge. We did the same with a co-located team at Salford Quays in the North West.”

Luke is now interested in capitalising on the benefits of the acquisition.

“SKM wanted to increase their rail capability in the UK and also leverage into international operations. The former Mouchel rail business brought strength and depth of project delivery in the UK with over 140 experienced staff. Colin Buchanan and Partners brought front-end skills including economic appraisal and transport modelling. Together, SKM can now offer a one-stop delivery service in the rail sector.”

The UK rail and bridges team sits within SKM’s Buildings and Infrastructure group. This is one of four groups targeted at market sectors, which also include mining and metals, power and energy, water and environment.

Luke has just returned from a three-week trip to Australia. “I met senior people from rail and road authorities and presented our capabilities to 16 clients. There are a lot of opportunities out there in addition to our UK work. We’re also expecting to develop business servicing the mining sector and dedicated mineral lines.

“There is a lot of cross-fertilisation between teams, a lot of virtual teaming. To complement the strengths of the existing teams, my rail and bridges team has particular expertise in strategic asset management, advanced composites, large bridge and multidisciplinary design.”

Strategic Asset Management

Asset management was one of the eight key areas investigated by Sir Roy McNulty’s Rail Value for Money Study. Recommendations included developing a high level framework for asset management. The study’s methodology included a ”should-cost” exercise.

SKM have an ongoing £1 million civil engineering strategic cost modelling project with Network Rail looking at just these issues. The work started in October 2010 and is due to complete by the end of this year. It involves developing life cycle and deterioration models to predict the investment needed to maintain Network Rail’s civil engineering assets.

Luke says, “A key achievement has been to apply a Bayesian process to develop a predictive asset model”.

This allows the vast volume of data within Network Rail’s asset database, including some 60,000 bridge spans and 100,000 earthworks, to be interpreted sensibly.

In statistical terms, a prior model is formed using available data including the global asset inventory, condition data, deterioration rates and average historic intervention costs. A subset of assets is chosen and studied in detail by hand, considering examination reports, detailed cost estimates, intervention profiles and alternative policy definitions.

The heart of the model is a Bayesian processor, a statistical method for probability forecasting, which takes the results of the detailed studies and applies their findings to the prior output, producing a “posterior model”. This posterior model effectively applies the learning from the subset of detailed studies to the whole database.

A web-based decision-support tool allows users to interrogate the results of the modelling exercise in detail as well as applying the effects of different policies. Different policies can be applied to different groups of assets such as primary routes or freight-only lines.

The relative effect of these policies can then be evaluated; for example, the difference between maintaining assets against an ultra-reliable high performance level, compared with maintaining to achieve lowest whole life cost, compared with intervening only when required to maintain an acceptable level for continued safe railway operation.

Luke adds, “We have been involved in this and similar work for over 15 years”. Whilst the acronyms change, the intent is the same.

“It is CECOST for the current Control Period 5 study. We worked on CECASE for CP4 and SACP for CP3.” The value of the modelling depends on the quality of data.

“Compared with 15 years ago, the input data is much better and the effectiveness of the modelling is much more apparent.”

“Reliable asset management models help to inform cost planning, and our work, not just with Network Rail but also London Underground, is developing the essential decision support tools to support this process.” Luke’s Australia visit was enlightening.

“They are behind the curve compared with the UK, but I expect they will come under similar pressures to develop this type of framework”.

Advanced Composites

Through the acquisition of the Mouchel rail business, SKM is now one of the leaders in the application of plastic composites. The firm boasts a portfolio of over 150 schemes using composites, including 20 for Network Rail.

Luke sat on the steering committees for two key publications, the Concrete Society and CIRIA (Concrete Industry Research and Information Association) guides to the use of composites on concrete and metal structures respectively.

Recent rail projects include Rhuba Glas bridge and Calder Viaduct. Both of these replaced life-expired timber decks with Fibre-Reinforced Polymer (FRP) units. These lightweight modules enabled the replacements to be carried out using light cranes in a short duration, giving a cheap, cost-effective method.

The team were also the designers for the first FRP bridge over the UK motorway network. Erected at Mount Pleasant in Lancashire over the M6, this bridge used FRP units rather than concrete for the deck section. It won a national award for innovation from the Institution for Highways and Transportation.

On the other side of the world, SKM designed the carbon-fibre strengthening scheme for 1500 metres of approach viaducts on the West Gate bridge in Melbourne. This is one of the longest and busiest bridges in Australia; originally built to carry 40,000 vehicles a day it now carries four times that number.

“The technology is mature. It is cheap, durable and shown to be effective”, says Luke. “Construction costs for the M6 bridge and the railway decks were comparable to conventional concrete, and much lower if you consider whole life costs”.

But there are barriers to wider adoption. “There is conservatism to be overcome. There is still a view that the material is in its infancy. We need continuing focus, the education of designers, clients, teaching on its use at universities.”

Luke points to the Airbus A380 double-deck plane, where composites account for a quarter of the structure. “In aerospace and Formula 1, composites are already the order of the day.”

Multi-disciplinary design

Luke’s background is bridge engineering. “SKM have a global bridge capability with over 100 bridge engineers”. Highlights in the UK include concept design of the centrepiece 400m-long viaduct for the £117 million Croxley Rail Link project. This scheme, awarded government funding in December 2011, will extend the Metropolitan Line to Watford Junction station.

Further north, Luke’s team undertook the detailed design for a three-span bridge over 15 railway tracks including the East Coast Main Line. This bridge was installed in January 2012 and forms a critical part of the £30 million White Rose Way Doncaster Southern Gateway improvement scheme.

SKM’s multi-disciplinary capabilities are showcased by their work on London Underground depots. SKM are lead designer for Taylor Woodrow’s £44 million project to extend and remodel Ealing and Upminster depots to accommodate the new Bombardier S7 train fleet.

The scope includes modifications to permanent way, traction power, signalling, structures, buildings, M&E and civil engineering. On top of that, SKM are also responsible for human factors considerations, systems engineering and design assurance.

The station design portfolio includes prestigious refurbishments of Liverpool Lime Street and Salford Central. SKM have completed 26 Approval in Principal designs for the step-free access-for-all station improvement programme.

Work has commenced at Green Park underground station to install air handling units. The detailed design for the cooling scheme has been carried out by SKM for Morgan Sindall’s £9 million project. The challenge for cooling the tube has always been about how to extract heat from the trains and stations.

The Green Park scheme uses boreholes and heat exchangers to pump unwanted heat into the aquifer below the park, the first time this type of installation has been used on London Underground.

SKM carried out the complex three-dimensional analysis of heat transfer at the platforms and throughout the cooling system.

Key values

SKM place a real emphasis on sustainability. Going beyond the typical corporate ‘core value’, sustainability is firmly embedded within the company. For example, an ambitious plan to reduce SKM’s own carbon emissions by 30% over three years was achieved last year.

With exciting projects, continued growth, ongoing recruitment and environmental credentials, you could be wondering how the share price is performing and whether this would be a sound investment. Indeed, one of SKM’s stated key values is “controlled risk-taking and steady wealth creation”.

However, SKM remains an independent company and is employee-owned. So it seems that the only way to join in is to join up.