A total renewal of the Danish signalling infrastructure

In January 2009, the Danish parliament decided to fund a €3.2 billion replacement programme of renewing all Danish railway signalling before 2021. The programme is one of its kind in Europe both in size and being unique in its approach of focusing on economies of scale and creating a competitive market situation to ensure the best possible price and quality.

The programme also introduces a step change in technology which maximises the possibilities and benefits of re-signalling the Danish railway network. Customer benefits from the programme includes: higher reliability, higher line speed at selected lines, homogenous high safety and nationwide interoperability.

Banedanmark’s signalling systems are aging to a point where many of the present signalling systems have overrun their technical service life. This leads to an increase in errors and delays for passengers and a general decrease in train traffic service level. A renewal based purely on life expiry would mean that 60% of all signalling installations would have to be replaced before 2025. So no matter what, major investments lay ahead.

Banedanmark conducted a strategic analysis demonstrating that a total renewal strategy would be the best economical and technical way of renewing the signalling systems. Further detailing this strategy in a detailed project proposal led to the governmental decision to replace all signalling on all Banedanmark’s railway lines before 2021 and replace all signalling on the Copenhagen S-bane before 2020.

The signalling programme is now well underway. The organisation has grown from 10 to 42 employees and a major consortium of consultants is in place.

Signalling today

The Banedanmark network includes 2,100km of lines and 3,200km of tracks. It serves about 560 trains from four major operators on the conventional network.

Existing technology

The existing Danish railway system is equipped with traditional signalling equipment i.e. colour light signalling, train detection by means of track circuits, and points operated by electric point machines. The mainline and regional network (Fjernbanen) is operated from three larger regional control centres and 11 smaller control centres.

One larger modern control centre manages the operation of the Copenhagen mass transit network (S-banen). All signalling to the driver is provided through colour light signals as described in the Danish rule book SR75, which like most national rule books is a specific set of Danish rules iteratively developed over a period of almost 100 years.

Danish ATP was developed around 1990 based on the Siemens ZUB100 platform.

The system uses balise transmission and infill loops to complement line side signalling.

Most main lines are fully equipped providing supplementary cab signalling, but secondary lines are either equipped with a scaled down ‘train stop’ system without cab signalling or unequipped. On densely trafficked main lines infill is widely used to heighten capacity.

On the Copenhagen S-bane, a loop based speed code ATP-system (HKT) provides continuous train supervision and protection on most of the network.

Age

About half of the signalling systems in use today are more than 50 years old. Nearly 80% are based on relay technology from the 1950s-1960s and some even on pre-World War 1 technology.

Even today there are lines with signalling which need urgent replacement and during the next 15 years 60% of the signalling assets’ life cycle expires. Experience shows that if the assets are not replaced in due time before the life cycle expires, the number and severity of delays will increase, along with the risk of high profile breakdowns.

The current signalling system causes 39,000 delayed trains per year corresponding to half of the total delays attributable to Banedanmark. Analysis has shown that with a continuation of the existing level of investment for renewal and maintenance in signalling equipment, the punctuality will steadily decrease, as the current level of renewal is lower than the level of life cycle expiry.

The concept of total renewal

Total renewal means replacing all signalling equipment. From basic train detection and point machines to the overall traffic management systems as well as on-board systems.

A new strategy for signalling

The idea of total renewal of all signalling equipment was conceived as a response to a number of urgent infrastructure management constraints:

• The high and increasing average age of Banedanmark’s signalling assets
• Lacking competition in the Danish market due to unique national rules, limited market and the associated monopolistic market situation
• High maintenance costs, safety approval, implementation of changes and spare parts
• Difficulties in the supply chain for spare parts
• Lacking expertise in the old technologies as staff is pensioned
• Lack of functionality and potential development of the railway.

On this background a comparable business case study of different renewal strategies was undertaken in 2006:

• A more traditional successive renewal based on life cycle expiry
• A total renewal of all signalling system regardless of age rolled out within a limited period

Despite the fact that there will be sunk costs associated with a total renewal strategy as all existing signalling systems are replaced regardless of age, the study showed that the cost, risk and benefits of a total replacement was a better option than a traditional renewal strategy.

Future signalling

Total renewal offers the possibility of a step change in technology from yesterday’s custom made distributed electromechanical and relay-based technologies to today’s industrial standard IT-components.

A step change in technology

The total renewal strategy will implement the newest proven signalling technology, based on standard industrial hardware components, redundant system configurations offering uniform system interfaces and high reliability. Furthermore, it gives the opportunity to implement full interoperability on the Danish conventional network (Fjernbanen) and to integrate the automatic traffic management in a few centres for the whole country.

To achieve these benefits, the natural choice for the conventional network has been ERTMS level 2 which offers substantial economical and operational benefits associated with the removal of all line side signals. The reduction of volatile equipment in the sensitive near-track environment reduces the vulnerability of the signalling system. The centralisation of interlocking logic and radio block centres on the basis of modern computers enables the realisation of the high performance vision, on the basis of redundant fault tolerant configurations.

The configuration will, in addition to the above, include condition monitoring of components, integration with passenger information systems and a uniform and higher country wide level of safety.

Roll-out

The overall roll-out strategy is to implement early deployment lines for extensive test and approval, followed by a swift roll-out of main lines and regional lines.

From 2009 through 2015, allowing for the preparation of the assets for signalling roll-out and fitting of rolling stock with ERTMS Level 2, investments will be focused on improving the lines with punctuality concerns through life extension of existing equipment.

During this period, the Signalling Programme will establish the full programme organisation and by the end of the period, three early deployment schemes covering approximately 300km are planned to be installed.

As infrastructure signalling renewal is the driver for the programme, double equipment of infrastructure is generally not feasible. As a consequence the roll-out is based on rolling stock fitted with ERTMS and a specific transmission module (STMDK) that can interpret existing ATP balises and loops. ERTMS level 2 roll-out is planned from 2018 to move prioritised south and east along the mainline (blue lines) in Jutland, as well as south and west along the mainline on Zealand including the new double track line København-Køge-Ringsted, and joining at the contract border on the western side of Funen.

The installation programme then moves back westwards and eastwards to install the remaining secondary routes (red lines).

The roll-out of ERTMS level 2 on the secondary lines have proved to be the cheapest way to achieve a necessary replacement of signalling on these lines as they benefit from the marginal cost of the full roll-out on main and regional lines. The use of the ERTMS Regional specification has been considered for these lines even though this approach is currently not sufficiently mature. Banedanmark will though evaluate the possibilities of including an ERTMS Regional like approach for these lines instead of ERTMS level 2.

Completion of the programme is reached in Western Jutland and the Zealand coast line by 2021 in time to coincide with the life expiry of the existing ATP equipment.