Publié le 12/05/2016 - Mis à jour le 12/05/2016
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Wagon cranes and trestle wagons in action!

About thirty kilometres from Paris, the small railway station of Goussainville is bristling with activity at the beginning of a weekend in October 2015. A well-timed ballet of work has started – only a few dozen metres away from the platforms – for the replacement of 12 railway switches. Two new tools will be used – a wagon crane and a trestle wagon.

The station in Goussainville is easily recognised by its 19th century architectural style and is served by the Paris area RER D Express on the Paris-North/Lille line. This railway station in a suburb of Paris is about to experience an unforgettable October weekend. Several other similar weekends have been planned until the end of November.

While the RER D Express trains continue to operate normally, some fifteen railway employees wearing fluorescent safety vests and hard hats are busily working near the train tracks. Each employee seems to perfectly master the tasks to be accomplished. They have already been at work for a week preparing this out of the ordinary renovation project: the replacement of 12 railway switches.

Project organised long beforehand

As part of the Vigirail network monitoring programme, the condition of railway switches is closely monitored. Any replacements are scheduled long before the works themselves, up to 3 or 4 years in advance. This is necessary to organise and plan the very large number of railway works in the Paris region. At the time, the network maintenance teams had determined that the operation of the lines running through Goussainville could still continue in total safety.

Hervé Brémand, Operations Director in the Ile-de-France Projects Division, explains that “The Paris area network is very dense. It represents 10% of the national network, 40% of the traffic and 70% of train journeys in France. It is an intensely used network which has – naturally – grown old. Modernisation works and quick renewal are therefore necessary.”

It is an intensely used network which has –naturally – grown old

Many trains alongside platforms in the Saint Lazare station in Paris

Acceleration of network modernisation programme
 

The replacement of railway switches is one of the priorities of the Vigirail programme. Since the programme was launched in October 2013, the number of renewal works has increased significantly, especially in the dense areas in the Ile-de-France region. As a result, 480 switches will be replaced in 2016 (including 175 in Ile-de-France), compared to 326 in 2013.

A long and painstaking preparation

While observing the site where the long ballast removal (extraction of 20 cm deep of ballast) and cleaning operations started in the morning, Nicloas Payen, Operations Director in the Ile-de-France Projects Division, remembers all the preliminary work performed in advance. It has already been 8 months since this renewal project was initiated, in particular by ordering the switches from the manufacturer (EIV Moulin-Neuf). It was then necessary to conduct a large number of surveying operations in order to define the works plan and to schedule the renewal operation over several weekends. While the preparation work can take place during the day and week, the actual technical operations are performed only during weekends. Three separate shifts work around the clock to limit the impact of the works on railway traffic.

Three separate shifts work around the clock

Two new tools now contribute to the successful completion of these major operations – the wagon crane and trestle wagon. Nicloas Payen, Operations Director in the Ile-de-France Projects Division, says “The wagon train and trestle wagon greatly limit train traffic interruptions during the works. In case the traffic does need to be changed, we try as much as possible to reduce the impact on passengers”.

The wagon train and trestle wagon greatly limit train traffic interruptions during the works

New production methods

But today, thanks to the wagon crane and trestle wagon, everything is different. There is no longer a need for an assembly zone as the switch arrives by train from the factory and is completely assembled. In addition, the assembly crossbar is no longer necessary and has been replaced by a lifting crane which sits on the train track. In the end, this represents an enormous savings in time and the ease of handling results in optimal quality. For Hervé, “only by using these new industrial processes are we able to optimise the renewal of the switches and deal with current and future needs.”

The savings in time is enormous and the ease of handling results in optimal quality

Installing an enormous lego

The tilting capability of the trestle wagon allows it to transport already assembled switches

The wagon crane and trestle wagon will soon arrive. Thanks to the successful management of this operation, with “forward planning” being the key word, it has been possible for these special devices to travel on the normal railway lines among the commercial train traffic. Olivier Joyaux, who is in charge of SNCF works project management for the North Paris area, ensures that everyone is in position. Safety at the works site is his main concern as the area is quite small.

Between the ovehead lines (which are switched off), the power poles and the nearby homes of neighbouring residents, the work stations of each employee must be optimised.

Thanks to the successful management of this operation, with “forward planning” being the key word, it has been possible for these special devices to travel on the normal railway lines among the commercial train traffic.

 

As planned, the trestle wagons arrive with a very full load from Chambly, the town in which the EIV Moulin-Neuf factory is located. This first switch travelled 50 kilometres before arriving on the site. Despite the enormous size of the switch, both in terms of width and height, the tilting platform of the trestle wagon has allowed it to travel among the traffic of other trains and past the different obstacles along its route, such as bridges. Thanks to its tilting capability, it was even able to travel through tunnels, like any normal train. 

Speed and efficiency

The wagon crane’s telescopic arm unfolds

The wagon crane – a real 128 tonne monster – positions itself just behind the trestle wagon. Under the powerful floodlights, the crane soon unfolds its impressive telescopic horizontal arm. When in its maximum position, it can reach out 27 metres and can easily lift the 30 tonne switch, which is 30 metres long.

With their headlamps on, the railway employees watch the first step of the operation which involves removing the old switch, whose fastenings have been taken off.

Slowly but surely, the old switch, which has lived its day, leaves the scene for the brand new one which will be laid in its place. Everything is scrupulously calculated as during the operations it is very important not to spill over onto the neighbouring tracks where normal train traffic continues. While giant showers of sparks cover the grinders in action, an excavator spreads and evens out the ballast.

A night shift team hard at work on a switch

The renewal operations are in full swing, the night is not over, and yet a new shift team arrives to take over. In a few hours it will install the switch.

However, there is still a considerable amount of work left to do before suspending the works site on Monday morning at dawn.

At this time, the old switch will be transported on the trestle wagon to the factory workshops in order to be recycled

During the renewal operations, we must be careful not to spill over onto the neighbouring tracks where normal train traffic continues

 

EIV Moulin-Neuf 
 

EIV Moulin-Neuf has several factories in France for the manufacturing of railway tracks and switches. In the Paris area, the factory is located in Chambly in the Oise department. It provides units in charge of track maintenance with a part of the equipment needed for the renewal or creation of fixed lines. The Chambly factory is the largest manufacturing site for railway switches in France. It manufactures more than half of the switches used for SNCF. This company has existed since 1918.