EP4179147B1 - Initial and final methods for laying long rails - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates, in general, to the technical field of work trains such as construction and renewal trains consisting of installing equipment necessary for the construction of railway tracks or, in the case of renewal, replacing all or part of the materials constituting the tracks, namely the rails and the fixed structure such as the sleepers, as well as the ballast which ensures the holding of the track on its platform, when these materials are degraded.

The invention relates more specifically to an initial method of laying long new rails of a railway track by a works train, a final method of laying, and a method of renewing old rails, already laid, of a railway track by long new rails initiated and/or finalized by these initial and/or final methods of laying long new rails.

STATE OF THE PRIOR ART

Builders or managers of rail transport networks regularly need to build new railway tracks or renovate existing ones, i.e. replace some of the elements that make them up, such as the rails and sleepers supporting the rails, as well as the fixing means and other accessories. A large part of this need for renewal is due to wear and tear on the tracks, but it can also involve replacing old models with more recent ones to enable better performance.

In the most complete case of renewal, such operations are carried out using a railway convoy such as a renewal train, comprising multiple specialized machines to carry out the different renewal operations. A typical complete track renewal operation uses specialized railway convoys comprising machines capable of carrying out the following operations in sequence: stripping, screening of ballast and evacuation of stripping products, by conveyor belts on wagons intended for discharge or by direct jet to the embankment, renewal of the track to be renewed (rails and sleepers), ballasting and lifting of the track, levelling and straightening, welding of rails, release of constraints, new levelling-straightening, adjustment of benches and cleaning of shoulders.

• approvisionnement de rails nouveaux de types « LRS » sous forme de « barres longues » (par exemple 324 mètres), préalablement réalisées dans des ateliers de soudage éloignés du chantier à partir de rails élémentaires (par exemple trois rails élémentaires de 108 mètres chacun), provenant des usines de fabrication de rails,
• enlèvement des attaches et tronçonnage des rails anciens,
• enlèvement des rails anciens,
• mise en place et alignement bout à bout des rails nouveaux, soudage aluminothermique des rails nouveaux entre eux mis bout à bout, fixation des rails neufs sur les traverses,
• raccordement des rails neufs à la ligne existante par soudures aluminothermiques, libération des contraintes (desserrage des attaches des rails neufs, frappe, resserrage des attaches), neutralisation du rail si nécessaire avec un tire-rail, chauffage à gaz ou autre méthode en fonction de la température au moment de la substitution,
• chargement et évacuation des rails anciens, et nettoyage du chantier.

The constant search for safety and increased speed of movement of railway vehicles has led to the design of rails called "long welded rails"("LRS") or "long bars". In the specific case of rail renewal, the renewal operation consists of replacing old rails with new long rails without intervening on the other elements of the track (platform, ballast, sleepers). It typically involves the implementation of the following steps:

• supply of new “LRS” type rails in the form of “long bars” (for example 324 metres), previously produced in welding workshops far from the site from elementary rails (for example three elementary rails of 108 metres each), coming from the rail manufacturing plants,
• removal of fasteners and cutting of old rails,
• removal of old rails,
• installation and end-to-end alignment of the new rails, aluminothermic welding of the new rails together placed end-to-end, fixing of the new rails to the sleepers,
• connection of the new rails to the existing line by aluminothermic welding, release of constraints (loosening of the fasteners of the new rails, striking, tightening of the fasteners), neutralization of the rail if necessary with a rail puller, gas heating or other method depending on the temperature at the time of substitution,
• loading and removal of old rails, and cleaning of the site.

On a track equipped with "normal" bars, the expansion is absorbed at the rail joints, a precisely adjusted clearance between two consecutive bars. allowing a slight elongation of the rails. Such a track is therefore relatively insensitive to temperature variations. This is not the case with a track equipped with long bars or "LRS" because in this case there are no joints between the rails to absorb the expansion. The tightening of the rail on the sleepers and the anchoring of the sleepers in the ballast oppose the free movement of the rails under the effect of temperature variations. The expansion of the rail being hindered, it is compensated by an increase in the internal tensions of the rail. When the resistance of the ballast is no longer sufficient to oppose the internal constraints of the rail, the rail ends up elongating: since it cannot elongate lengthwise, it does so in the lateral direction, thus creating a deformation of the geometry of the track frame. Such deformations of the track are obviously extremely dangerous.

To considerably reduce the risks of breakage of said rails in cold weather or of deformation in extreme heat, it is known to carry out an operation called "neutralization" of the new rails. This neutralization makes it possible to fix the rails at a given state of expansion, either at a determined average temperature (for example 25°C) when the neutralization takes place by heating the rails, or with a stretching of the rails corresponding to their expansion at this average temperature when the neutralization operation is carried out by stretching the rails.

All these operations, carried out step by step, by section of rail, rail by rail or long bar by long bar, require a lot of time as well as an interruption of traffic. The same operations are necessary when laying a new track, with the exception of course of the dismantling of the old ties and the evacuation of the old rails.

Solutions capable of implementing rail renewal operations with a rail neutralization step have been known for a long time, but at relatively low speeds, or even which are not adapted to the renewal of rails for the laying of long welded rails. Other existing solutions require the use of several different rail convoys to each implement only part of the renewal operations, which is costly. Furthermore, such renewal projects are very long and require a larger workforce. Finally, when such solutions propose a neutralization of the rail, this neutralization turns out to be non-existent at the ends of the new rails connected to the old railway line or carried out in an artisanal manner by separate means.

Examples of rail renewal operations are described in the documents WO 2017/017600 A1 , WO 2007/118977 A2 And WO 2014/080118 A1 .

PRESENTATION OF THE INVENTION

The invention aims to remedy all or part of the drawbacks of the state of the art by proposing in particular a solution making it possible to implement a method of renewing old rails with long new rails, offering the shortest possible immobilization of the railway track to reduce the duration of the work, while guaranteeing good safety of the railway track laid, in particular at the ends of the old rails framing a portion of the track to be renewed, corresponding to the ends of the new rails connected to the old railway track.

• une étape de pose d'une partie au moins d'un premier des longs rails nouveaux sur la structure fixe à au moins une extrémité d'un rail ancien de jonction ;
• une étape de raccordement temporaire bout à bout de l'extrémité du rail ancien de jonction avec au moins une extrémité du premier long rail nouveau par au moins un dispositif de raccordement temporaire ;
• une étape de raccordement permanent, par exemple par soudage, par exemple aluminothermique, des deux extrémités raccordées du rail ancien de jonction et du premier long rail nouveau ;
• -préalablement à l'étape de pose, une étape de chauffage ou de refroidissement de neutralisation à la température de référence, d'au moins une portion d'extrémité du premier long rail nouveau, la portion d'extrémité comportant l'extrémité du premier long rail nouveau à laquelle doit être raccordée l'extrémité du rail ancien de jonction.

To do this, according to a first aspect of the invention, an initial method of laying long new rails of a railway track by a work train traveling in a direction of travel is proposed, the initial method being intended to be implemented during a method of renewing old rails of the railway track of the type comprising a phase during which the long new rails are laid and then fixed to a fixed structure of the railway track when the work train travels in the direction of travel, the initial laying method comprising:

• a step of laying at least part of a first of the long new rails on the fixed structure at at least one end of an old junction rail;
• a step of temporarily connecting end to end the end of the old junction rail with at least one end of the first long new rail by at least one temporary connecting device;
• a permanent connection step, for example by welding, for example aluminothermic, of the two connected ends of the old junction rail and the first long new rail;
• - prior to the installation stage, a neutralization heating or cooling stage at the reference temperature, of at least one end portion of the first long new rail, the end portion comprising the end of the first long new rail to which the end of the old junction rail is to be connected.

"Long rails" are rails also called "long welded rails" ("LRS") or "long bars". These long welded rails are formed from one or a plurality of elementary rails of normal length, or "normal bars", welded together, generally in welding workshops far from the construction site, and thus forming a single continuous unit. The distinction between long welded rails and rails made of normal bars is then very clear in terms of length, with long welded rails being able to extend over several hundred meters or even kilometers. The railway track here concerns both tracks laid on ballast, or tracks without ballast laid on other supports (tracks on concrete, tracks on slabs, etc.). The fixed structure of the railway track can vary depending on the type of track and may include, for example, sleepers, slabs, a concrete platform, etc.

Thanks to such a combination of characteristics, such a method allows a connection between the old railway track and the new railway track with a level of safety guaranteed by the neutralization of the rails before their fixing equivalent to the rest of the track, in particular here at the end portion of the first long new rail. Of course, the initial laying method can be implemented on a row of rails of the railway track or simultaneously on the two rows of parallel rails of the railway track.

According to one embodiment, the initial laying method comprises a step of neutralizing, preferably by heating or cooling, an end portion of the old junction rail comprising the end of the old junction rail to which the end portion of the first long new rail is to be connected.

According to one embodiment, the neutralization heating or cooling step at the reference temperature of the end portion of the first new long rail is preceded by the neutralization step, preferably by heating or cooling, of the end portion of the old junction rail comprising the end of the old junction rail to which the end portion of the first long new rail is to be connected.

According to one embodiment, the heating or cooling step of neutralizing the end portion of the old junction rail is carried out by thermal transfer or insulation means, which preferably comprise a source of infrared radiation for heating said end portion of the old junction rail to the reference temperature.

According to one embodiment, prior to the step of end-to-end connection of the end of the old junction rail with the end of the first long new rail by the temporary connection device, a step of cutting the old junction rail is carried out to form the end of the old junction rail to be connected.

According to one embodiment, the temporary connection device comprises at least one fishplate or rail puller. The temporary connection devices such as the fishplate or rail puller have the function of keeping the ends of the rails abutted, regardless of the variations in external temperatures, thus ensuring the perfect joint of the ends. Another function is to maintain the reference length of the old and new rails until the step of welding the ends. This temporary connection device is removed once the ends of the rails are welded, and the weld has cooled after a predetermined cooling time, generally twenty minutes. The permanent connection, subsequent to the temporary connection, makes it possible to guarantee circulation at normal speed of a railway vehicle, while the temporary connection only allows at best circulation at reduced speed.

According to one embodiment, prior to or subsequent to the step of temporary end-to-end connection of the end of the old junction rail with the end of the first long new rail by the temporary connection device, said ends undergo a preparation step with a view to the permanent connection step, for example an abrasion machining step.

• une étape de pose d'une partie au moins d'un dernier des longs rails nouveaux sur la structure fixe à au moins une extrémité d'un rail ancien de jonction ;
• une étape de raccordement temporaire bout à bout d'une extrémité du dernier long rail nouveau avec au moins l' extrémité du rail ancien de jonction par au moins un dispositif de raccordement temporaire ;
• une étape de raccordement permanent, par exemple par soudage, par exemple aluminothermique, des deux extrémités raccordées du rail ancien de jonction et du dernier long rail nouveau ;
• -préalablement à l'étape de pose, une étape de chauffage ou de refroidissement de neutralisation à la température de référence, d'au moins une portion d'extrémité du dernier long rail nouveau, la portion d'extrémité comportant l'extrémité du dernier long rail nouveau à laquelle doit être raccordée l'extrémité du rail ancien de jonction.

According to another aspect of the invention, the latter relates to a final method of laying long new rails of a railway track by a work train running in a direction of travel, the final method being intended to be implemented during a method of renewing old rails of the railway track of the type comprising a phase during which the long new rails are laid and then fixed to a fixed structure of the railway track when the work train runs in the direction of travel, the final laying method comprising:

• a step of laying at least part of one of the last of the long new rails on the fixed structure at at least one end of an old junction rail;
• a step of temporarily connecting end to end one end of the last long new rail with at least the end of the old junction rail by at least one temporary connecting device;
• a permanent connection step, for example by welding, for example aluminothermic, of the two connected ends of the old junction rail and the last long new rail;
• - prior to the laying step, a neutralization heating or cooling step at the reference temperature, of at least one end portion of the last long new rail, the end portion comprising the end of the last long new rail to which the end of the old junction rail must be connected.

According to one embodiment, the final laying method comprises a step of neutralizing, preferably by heating or cooling, an end portion of the old junction rail comprising the end of the old junction rail to which the end portion of the first long new rail is to be connected.

According to one embodiment, the neutralization heating or cooling step at the reference temperature of the end portion of the last long new rail is followed by the neutralization step, preferably by heating or cooling, of the end portion of the old junction rail comprising the end of the old junction rail to which the end portion of the last long new rail is to be connected.

The steps implemented and the means used for this final process are mutatis mutandis similar to the initial process. Thus, and in the same way as for the end portion of the first long new rail, such a process allows a connection between the old railway track and the new railway track, with a level of safety guaranteed by the neutralization of the rails before their fixing comparable to the rest of the track, in particular here at the end portion of the last long new rail.

According to another aspect, the invention also relates to a method for renewing old rails of a railway track of the type comprising a phase during which the long new rails are laid and then fixed to a fixed structure of the railway track by a work train running in one direction of travel, the renewal method being characterized in that the phase is initiated by the initial method of laying long new rails as described above and/or is finalized by the final method of laying long new rails as described above.

According to one embodiment, the renewal method comprises a first phase during which new long rails are unloaded along the railway track from a transport train of a work train traveling in a first direction of travel, and comprises a second phase in which the work train travels in a second direction of travel opposite to the first direction of travel, the new long rails being laid and then fixed to the fixed structure such as the sleepers of the railway track during the second phase.

Such a renewal process can be implemented by a single work train. Furthermore, the operations carried out can be sequenced in an optimized manner. It is no longer necessary to carry out all the operations at the same time, or sequenced successively in a single direction of circulation, which would have the effect of reducing the speed of circulation on the site according to the most restrictive operation. Indeed, when the work train implements all the operations in series, only one operation requiring the immobilization of the work train is needed to limit the progress of the site on the other operations. By proceeding in such a sequenced manner in two phases, and by distributing the renewal operations both in one direction of circulation, then in the other direction of traffic, a reduction in the time of the works is observed for an equivalent length of renewed rails. Finally, it is possible to carry out all these operations during the same temporary interruption of traffic while minimizing the duration of this interruption.

According to one embodiment, the work train comprises vehicles mounted on wheel sets, for example bogies, the neutralization step by neutralization heating or cooling being carried out in an area of the work train located upstream of the first of the wheel sets of the work train bearing on the long new rails, relative to the second direction of travel.

According to one embodiment, the neutralization heating or cooling step is followed by a step of maintaining and/or correcting the reference temperature of the neutralized rail portion, by thermal transfer or insulation, the step of maintaining and/or correcting the reference temperature preferably being carried out in a zone of the work train located at least downstream of the first of the wheel sets bearing on the long new rails, relative to the second direction of travel. Preferably, the thermal transfer or insulation means comprise a source of infrared radiation. During a step of maintaining and/or correcting the reference state, the maintenance means can provide a correction of the neutralization, in addition to said neutralization step, so as for example to tend towards a reference state that would not have been reached during the previous neutralization step.

Once the long new rails have been laid on the fixed structure, a certain distance separates the area where these rails are laid from an area where said rails are fixed to the fixed structure. Such a step of maintaining and/or correcting the reference state, for example the reference temperature, downstream with reference to the second direction of travel and at a distance from the neutralization step makes it possible to guarantee fixing of the neutralized long new rails, in particular with a temperature maintained at the reference temperature. This makes it possible to further reduce the risks of breakage of said rails or deformation of the track depending on the heat differences to which they are subjected.

The initial process is an initial phase or commitment to the stages of laying the long new rails and dismantling the old rails by the works train to begin the renewal starting from this initial configuration of a portion of railway track.

Preferably, the neutralization during the initial process of laying the end portion of the old junction rail is carried out by all or part of the means for maintaining and/or correcting the reference temperature.

The final process is a final or clearance phase of the stages of laying the long new rails and dismantling the old rails by the works train to finalize the renewal of a section of railway track.

Preferably, the neutralization during the final process of laying the end portion of the old junction rail is carried out by all or part of the means for maintaining and/or correcting the reference state.

BRIEF DESCRIPTION OF THE FIGURES

• [Fig. 1] : un schéma d'un convoi ferroviaire comprenant un train de travaux selon un mode de réalisation de l'invention ;
• [Fig. 2A] : un schéma d'un détail de la figure 1 ;
• [Fig. 2B] : un schéma d'un détail de la figure 1 ;
• [Fig. 2C] : un schéma d'un détail de la figure 1 ;
• [Fig. 2D] : un schéma d'un détail de la figure 1 ;
• [Fig. 3A] : un schéma du convoi ferroviaire tel qu'illustré sur la figure 1, durant une première phase d'un procédé de renouvellement selon ce mode de réalisation ;
• [Fig. 3B] : un schéma du convoi ferroviaire tel qu'illustré sur la figure 1, durant une deuxième phase d'un procédé de renouvellement selon ce mode de réalisation ;
• [Fig. 4] : un schéma d'un détail de la figure 3B ;
• [Fig. 5A] : un schéma d'une étape d'une phase initiale de la deuxième phase du procédé de renouvellement selon ce mode de réalisation ;
• [Fig. 5B] : un schéma d'une étape de la phase initiale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 5A ;
• [Fig. 5C] : un schéma d'une étape de la phase initiale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 5B ;
• [Fig. 5D] : un schéma d'une étape de la phase initiale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 5C ;
• [Fig. 5E] : un schéma d'une étape de la phase initiale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 5D ;
• [Fig. 5F] : un schéma d'une étape de la phase initiale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 5E ;
• [Fig. 6A] : un schéma d'une étape d'une phase finale de la deuxième phase du procédé de renouvellement selon ce mode de réalisation ;
• [Fig. 6B] : un schéma d'une étape de la phase finale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 6A ;
• [Fig. 6C] : un schéma d'une étape de la phase finale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 6B ;
• [Fig. 6D] : un schéma d'une étape de la phase finale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 6C ;
• [Fig. 6E] : un schéma d'une étape de la phase finale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 6D ;
• [Fig. 6F] : un schéma d'une étape de la phase finale de la deuxième phase du procédé de renouvellement, postérieure à celle de la figure 6E ;
• [Fig. 7] : un diagramme illustrant le fonctionnement du train de travaux suivant son évolution le long de la voie ferrée.

Other characteristics and advantages of the invention will emerge from reading the description which follows, with reference to the appended figures, which illustrate:

• [ Fig. 1 ]: a diagram of a railway convoy comprising a works train according to one embodiment of the invention;
• [ Fig. 2A ] : a diagram of a detail of the figure 1 ;
• [ Fig. 2B ] : a diagram of a detail of the figure 1 ;
• [ Fig. 2C ] : a diagram of a detail of the figure 1 ;
• [ Fig. 2D ] : a diagram of a detail of the figure 1 ;
• [ Fig. 3A ]: a diagram of the railway convoy as illustrated on the figure 1 , during a first phase of a renewal process according to this embodiment;
• [ Fig. 3B ]: a diagram of the railway convoy as illustrated on the figure 1 , during a second phase of a renewal process according to this embodiment;
• [ Fig. 4 ] : a diagram of a detail of the Figure 3B ;
• [ Fig. 5A ]: a diagram of a step of an initial phase of the second phase of the renewal method according to this embodiment;
• [ Fig. 5B ]: a diagram of a step of the initial phase of the second phase of the renewal process, subsequent to that of the Figure 5A ;
• [ Fig. 5C ]: a diagram of a step of the initial phase of the second phase of the renewal process, subsequent to that of the Figure 5B ;
• [ Fig. 5D ]: a diagram of a step of the initial phase of the second phase of the renewal process, subsequent to that of the Figure 5C ;
• [ Fig. 5E ]: a diagram of a step of the initial phase of the second phase of the renewal process, subsequent to that of the Figure 5D ;
• [ Fig. 5F ]: a diagram of a step of the initial phase of the second phase of the renewal process, subsequent to that of the Figure 5E ;
• [ Fig. 6A ]: a diagram of a step of a final phase of the second phase of the renewal process according to this embodiment;
• [ Fig. 6B ]: a diagram of a step in the final phase of the second phase of the renewal process, subsequent to that of the Figure 6A ;
• [ Fig. 6C ]: a diagram of a step in the final phase of the second phase of the renewal process, subsequent to that of the Figure 6B ;
• [ Fig. 6D ]: a diagram of a step in the final phase of the second phase of the renewal process, subsequent to that of the Figure 6C ;
• [ Fig. 6E ]: a diagram of a step in the final phase of the second phase of the renewal process, subsequent to that of the Figure 6D ;
• [ Fig. 6F ]: a diagram of a step in the final phase of the second phase of the renewal process, subsequent to that of the Figure 6E ;
• [ Fig. 7 ]: a diagram illustrating the operation of the work train as it moves along the railway track.

For clarity, identical or similar elements are identified by identical reference symbols throughout the figures.

DETAILED DESCRIPTION OF AN EMBODIMENT

THE Figures 1, 2A, 2B, 2C and 2D illustrate diagrams of a railway convoy 10 comprising a works train 100 according to an embodiment of the invention. The works train 100 comprises a power car 110 at the head of the train followed, directly here, by a transport train 120 coupled to the power car 110. The transport train 120 is configured to ensure the transport of long new rails 22 to be transported to a works zone Z0 and preferably also to store old rails 21 to be evacuated from this same works zone Z0, as the long new rails 22 are laid. The work train 100 comprises a work train 130 coupled to the rear of the transport train 120. The work train 130 is illustrated in a variant equipped with three work vehicles 131, 132, 133 coupled successively, in particular a first work vehicle 131, a second work vehicle 132 and a third work vehicle 133. It has a variable composition, that is to say that its composition in cars can vary punctually, during a passage in the workshop for example, but which once determined, generally for a specific site, only changes during a passage in the workshop.

It should be noted that "old" rails are understood as rails already laid, pre-existing on a track to be renewed, new rails are understood as rails replacing these rails already laid. These terms do not predict the wear or age of the rail as such.

The railway convoy 10 comprises a welding machine 140 which is here a railway machine that can be removably coupled to the tail of the work train 100, in particular here to the tail of the work train 130, relative to a first direction of travel F1. Such a coupling makes it possible to move a railway convoy to the work zone Z0. The welding machine 140 is designed to be uncoupled from the work train 100 once it has arrived near the work zone Z0, as illustrated on the figure 1 , so as to be able to circulate independently of the work train 100, preferably at a distance from the work train 100. Its usefulness will be better understood by reading the renewal method described below.

• une première phase A, durant laquelle des longs rails nouveaux 22 sont déchargés le long de la voie ferrée 20 depuis la rame de transport 120 du train de travaux 100 circulant dans un premier sens de circulation F1, et
• une deuxième phase B durant laquelle le train de travaux circule sur un chemin inverse, à savoir dans un deuxième sens de circulation F2 opposé au premier sens de circulation F1, et durant laquelle les longs rails nouveaux 22 sont posés puis fixés sur une structure fixe 23 de la voie ferrée 20, ici des traverses 23.

THE Figures 3A and 3B illustrate diagrams of this railway convoy 10, respectively in a first and a second phase A, B of the renewal of the railway track 20: this involves the renewal of the old rails 21 of the railway track 20 with long new rails 22. The process of renewing old rails 21 of the railway track 20 with long new rails 22 is generally broken down into:

• a first phase A, during which new long rails 22 are unloaded along the railway track 20 from the transport train 120 of the works train 100 running in a first direction of travel F1, and
• a second phase B during which the works train travels on a reverse path, namely in a second direction of travel F2 opposite to the first direction of travel F1, and during which the long new rails 22 are laid then fixed on a fixed structure 23 of the railway track 20, here sleepers 23.

In other words, the works train 100 moves on the railway track 20 in two phases, outward A and return B , during which it implements different steps, the combination of these two phases A and B making it possible to ensure the renewal of the railway track 20.

During the first phase A, the new long rails 22 are unloaded successively along the railway track 20 from the transport train 120 of the work train 100, this as the work train advances in the first direction of travel F1, pulled by the motor car 110. The motor car 110 can optionally provide traction assistance or not to the work train 100 which is equipped with its own advance system, in particular by distributed drive wheel sets. Thus, the transport to the construction site can be carried out in two variants: with a self-propelled machine specific to the work train, or by being towed by a locomotive. On the construction site, the self-propelled machine can also be assisted by traction provided by the locomotive.

Depending on the desired configuration, these long new rails 22 can be unloaded outside the railway track 20 along the old rails 21 to be renewed, or in the center of the railway track 20. Once the first phase A is completed, this results in an alignment of long new rails to be laid, arranged successively along the railway track 20 and around it. A step of placing supports on the ground, such as roller supports, is implemented prior to unloading the long new rails, preferably by one of the vehicles of the works train 130, so that the long new rails come to rest, on the ground on these roller supports and not directly on the ground or the ballast. The station 107' configured to ensure the laying or installation of the roller supports is located upstream of that of the unloading of the long new rails 22, with reference to this first direction of circulation F1. In this example, the work station 107' ensuring the installation of the roller supports is implemented by the first vehicle 131 of the work train, in front of the second vehicle 132 at which the unloading is ensured, with reference to this first direction of circulation F1.

In parallel with this operation of unloading the long new rails 22 along the railway track 20, still during the first phase A, each of the ends of the unloaded long new rails 22 undergoes a preparation step with a view to a permanent connection step, for example welding. Such a preparation step comprises for example an abrasion machining step. This welding preparation step is implemented by a welding preparation station 116 carried by the welding machine 140. This welding machine 140 is in this example a railway machine. In particular configurations, the welding machine could also be a rail-road welding truck or a rail-road welding excavator. The welding machine 140 travels independently of the work train 100 and in the first direction of travel F1, behind it. During the first phase A, the welding machine 140 therefore travels generally in the same direction F1 as the work train 100, at a distance d behind it, this distance being variable during the first phase A. In this way, while the work train 100 travels at a quasi-continuous and homogeneous speed to unload the long new rails 22, with a few breaks so as to guide the long new rails 22 towards a train laying area, these breaks marking stages A3 in the progress of the worksite (see there figure 7 ), the welding machine 140 operates at a different speed and in a sequenced manner, alternating static phases, when preparing to weld the ends of the long new rails 22, and dynamic phases where it progresses along the railway track 20 to reach a next end, and so on.

During the second phase B , the works train moves in a second direction of travel F2 opposite to the first direction of travel F1, thus making the reverse journey. The railway convoy 10 with successively, from front to back relative to the first direction of travel F1, the locomotive 110 (which is optional if it is not used as a traction aid during the worksite) then the transport train 120 and the works train 130 then travel in reverse order: the works train 130 is at the head of the works train 100, with reference to this second direction of travel F2. The welding machine 140 which travelled independently and at a distance behind the works train during the first phase A, travels during the second phase B still independently and at a distance from the works train 100, but this time in front of it, with reference to this second direction of travel F2.

Several operations are implemented substantially jointly during this second phase B.

On the one hand, the old rails 21 of the portion of railway track to be renewed are dismantled by the work train 100, then preferably loaded onto the transport train 120 of the work train 100. The old rails 21 are cut at regular intervals as they are loaded onto the transport train 120 of the work train 100 in order to be stored in a plurality of separate sections of old rails 21. In this way, the transport train 120 can be used both to store the long new rails 22 and the old rails 21. Another possible alternative is that the old rails 21 are moved along the railway track 20 from the railway track 20 itself, in particular from their location on the sleepers 23. The transport train 120 is provided with handling equipment 121 such as a handling gantry making it possible to ensure a number of operations such as cutting the old rails 21, or gripping the rails 21, 22, etc. Alternatively or in addition, these operations can also be carried out in whole or in part manually. Preferably the loading path of the old rails 21 follows the reverse path to that of unloading the new rails 22. In this way the multiplication of equipment is limited, in particular on the second vehicle 132 of the works train 130.

The welding machine 140, which therefore travels during this second phase B in front of the work train 100 and in the same direction of travel F2 as the latter, comprises welding means 115 and carries out welding operations, preferably electric welding, of the long new rails 22 end to end. The welding machine 140 operates at a sufficient distance from the work train 100 so as to allow the electric welding to cool before the installation of the long new rail 22. A cooling time of the order of 20 minutes for example can thus be guaranteed.

The laying of the long new rails 22 on the sleepers 23 of the railway track 20 is carried out by the work train 100 at a laying zone Z1 located downstream of the welding machine 140. This laying operation consists in particular, but not exclusively, in moving the long new rails 22 arranged along the railway track 20, to install them on the sleepers 23, at the same place where the old rails 21 are previously dismantled, this dismantling taking place in a dismantling zone Z6 upstream relative to the laying zone Z1. The dismantling of the old rails 21 and the laying of the long new rails 22 are carried out in parallel and therefore progress in a synchronized manner. The same vehicle 132 of the works train 130 mainly implements the dismantling and laying steps so that the laying zones Z1 and dismantling zones Z6 are located opposite the same vehicle 132 of the works train 130, these steps being implemented by the same second vehicle 132. In this way, the discontinuity of the railway track 20 caused by the dismantling of the old rails 21 and the laying of the long new rails 22 is spanned by the same vehicle 132 carried by a wheel set such as a bogie 101 upstream relative to the second direction of travel F2, running on old rails 21 and a wheel set such as a bogie 101 downstream running on long new rails 22 positioned on the sleepers 23. This bogie 101 downstream of the vehicle 132 implementing these two steps constitutes the first of the bogies 101 of the work train 100 on the new long rails 22, in relation to the second direction of travel F2.

A step of neutralization by portions 24 of the long new rails 22 by heating or cooling to a reference temperature is implemented to allow fixing of the rails at a given expansion reference state. During this neutralization step, located in a zone Z2 (see the figure 4 ), each of the portions 24 of the long new rails 22 is heated or cooled to the reference temperature by main neutralization means 111 located in the same zone Z2 before being laid on the sleepers 23 of the railway track 20. The main neutralization means 111 preferably comprise a heater such as induction heating. Preferably, the main neutralization means 111 comprise cooling means, for example equipment for projecting a liquid flow such as water or a gas flow, ideally air, possibly compressed, dry ice, etc.

This neutralization zone Z2 is located upstream of the first of the wheel sets, in particular here the bogies, 101 of the work train 100 carrying the long new rails 22, relative to the second direction of circulation F2.

To avoid too great a temperature difference between the reference temperature and the temperature of the rails at the time of their attachment to the sleepers 23, the neutralization heating or cooling step is followed by a step of maintaining and/or correcting the reference temperature of the neutralized rail portion 24 , by thermal transfer or insulation. Preferably, the thermal transfer or insulation means comprise a source of infrared radiation.

This step of maintaining and/or correcting the reference temperature is carried out in a zone Z3 of the work train 100 located at least downstream of the neutralization zone Z2 and downstream of the first of the bogies 101 bearing on the long new rails 22, relative to the second direction of travel F2. This zone Z3 continues downstream of the second bogie bearing on the new rails in a variant illustrated in FIG. figure 4 . The new long rails 22 are then fixed to the sleepers 23 by fasteners in a zone Z4 of the work train 100 located directly downstream of the zone Z3 of the work train in which the step of maintaining and/or correcting the reference temperature is carried out. This step of maintaining and/or correcting of the reference state, namely the reference temperature, is implemented by at least means of maintaining and/or correcting 113 the reference temperature located at the level of this same zone Z3.

Of course, an additional step of maintaining and/or correcting the reference temperature of the portion of rail 24 neutralized by thermal transfer or insulation can be implemented on another zone Z5 of maintaining and/or correcting the upstream reference temperature, for example by additional means of maintaining and/or correcting 112 the reference temperature, upstream of the first of the bogies 101 bearing on the long new rails 22, and downstream of the neutralization zone Z2 (see the figure 4 ). Indeed, a significant distance separates the main neutralization means 111 from the first of the bogies 101 bearing on the long new rails 22, approximately 8m in this embodiment, which justifies the interest of such an additional device for maintaining and/or correcting 112 the upstream reference temperature. Of course, other complementary means for maintaining the reference temperature may be used, such as complementary means for maintaining and/or correcting 114 the reference temperature which are located between the means 113 and 112, at the level of the first and second of the bogies 101 bearing on the long new rails 22 : the first of the bogies 101 bearing on the long new rails 22 forming the downstream bogie of the second vehicle 132 and the second of the bogies 101 bearing on the long new rails 22 forming the upstream bogie of the first vehicle 131 which succeeds it with reference to the second direction of travel F2.

Ideally, the step of maintaining and/or correcting the reference state is implemented over the entire portion of rail located between its neutralization and its fixing, the fixing of the fasteners being directly downstream of the maintenance and/or correction to the reference state. In practice, due to the presence of certain equipment or a work station necessary for example for the installation of the fasteners 107 before their fixing (screws and/or clips) by a work station 108, care will be taken to ensure that the distance separating a zone Z4 of the work train in which the step of fixing the long new rail is carried out from the zone Z3 of the work train in at which the step of maintaining and/or correcting the reference state is carried out, is less than 7m.

During this second phase B , initial and final phases must be implemented to initiate and finalize the laying of the long new rails 22 at the same time as the dismantling of the old rails 21 in relation to the pre-existing railway track to which it must be connected.

• une étape de démontage des attaches fixant les rails anciens au voisinage et en aval des rails à renouveler, c'est-à-dire sur une portion située en aval d'une extrémité 211' d'un rail ancien de jonction 211 à laquelle doit être raccordée une portion d'extrémité 221' d'un premier des longs rails nouveaux 221, par rapport au deuxième sens de circulation F2 (voir la figure 5B) : cette étape de démontage des attaches est mise en oeuvre par des moyens de démontage 102 situés de préférence au niveau du troisième véhicule 133 amont de la rame de travaux 130 dans ce sens de circulation F2 lorsqu'il est employé ou peut être mis en oeuvre également en amont du véhicule 132 mettant en oeuvre l'étape de neutralisation ;
• une étape de chauffage ou de refroidissement de neutralisation de la portion d'extrémité 211' du rail ancien de jonction 211 en aval de son extrémité 211' à laquelle doit être raccordée la portion d'extrémité 221' du premier long rail nouveau 221, par rapport au deuxième sens de circulation F2 (voir la figure 5B), la portion d'extrémité 211' comportant l'extrémité 211' du rail ancien de jonction 211 à laquelle doit être raccordée la portion d'extrémité 221' du premier long rail nouveau : cette étape de chauffage ou de refroidissement est de préférence mise en oeuvre par les moyens de maintien et/ou de correction 113, 114, 112 de la température de référence, plutôt que par les moyens 111 de chauffage ou de refroidissement de neutralisation. Ces moyens de transfert ou d'isolation thermique sont portés en partie (112) par le deuxième véhicule 132 attelé devant le premier véhicule 131 et situés en aval de la rame de travaux 130 dans ce sens de circulation F2 ;
• une étape de coupe du rail ancien 21, en particulier du rail ancien de jonction 211 (voir la figure 5C) créant ainsi une discontinuité dans la voie ferrée 20 dans une position enjambée de la discontinuité de la voie ferrée 20 par le véhicule 132 effectuant le chauffage ou de refroidissement de neutralisation, le démontage des rails anciens 21 et la pose des longs rails nouveaux 22 au fur et à mesure que le train circule suivant le sens de circulation F2 ;
• une étape de chauffage ou de refroidissement de neutralisation de la portion d'extrémité 221' du premier long rail nouveau 221 comportant l'extrémité 221' à laquelle doit être raccordée l'extrémité 211' du rail ancien de jonction 211 ;
• après la pose d'une partie au moins du premier long rail nouveau 221 sur les traverses 23 à l'extrémité 211' du rail ancien de jonction 211, une étape de raccordement temporaire bout à bout de l'extrémité 211' du rail ancien de jonction 211 avec l'extrémité 221' du premier long rail nouveau 221 par un dispositif de raccordement temporaire 30 tel qu'une éclisse ou un tire-rail (voir la figure 5D), garantissant le passage des bogies 101 et permettant de maintenir une position bout à bout et idéalement neutre, malgré d'éventuelles variations de température extérieure ;
• lorsque le train de travaux 100 a dépassé le dispositif de raccordement temporaire 30, une étape de raccordement permanent, par exemple de soudage, de préférence aluminothermique, des deux extrémités raccordées 211', 221' suivie d'une étape de retrait du dispositif de raccordement temporaire 30.

To do this, the second phase B includes an initial phase, illustrated in detail on the Figures 5A, 5B, 5C, 5D, 5E and 5F . In these figures, only the first and second vehicles 131 and 132 of the work train 130 are illustrated to simplify the views. In an initial configuration, the old rails 21 extend continuously and are fixed to the sleepers 23 by fasteners (not illustrated), while the long new rails 22 are laid along the railway track (see Figure 5A ). The initial phase corresponds to the start of the steps of laying the long new rails 22 and dismantling the old rails 21 by the works train 100 to begin the renewal starting from this initial configuration. This initial phase includes in particular, but not exclusively, the following steps, preferably for each of the two parallel rails at the same level of the railway track 20 :

• a step of dismantling the fasteners fixing the old rails in the vicinity and downstream of the rails to be renewed, that is to say on a portion located downstream of an end 211' of an old junction rail 211 to which an end portion 221' of a first of the long new rails 221 must be connected, relative to the second direction of circulation F2 (see the Figure 5B ): this step of dismantling the fasteners is implemented by dismantling means 102 preferably located at the level of the third vehicle 133 upstream of the works train 130 in this direction of circulation F2 when it is used or can also be implemented upstream of the vehicle 132 implementing the neutralization step;
• a heating or cooling step for neutralizing the end portion 211' of the old junction rail 211 downstream of its end 211' to which the end portion 221' of the first long new rail 221 must be connected, relative to the second direction of F2 circulation (see the Figure 5B ), the end portion 211' comprising the end 211' of the old junction rail 211 to which the end portion 221' of the first new long rail must be connected: this heating or cooling step is preferably implemented by the means 113, 114, 112 for maintaining and/or correcting the reference temperature, rather than by the neutralization heating or cooling means 111. These thermal transfer or insulation means are carried in part (112) by the second vehicle 132 coupled in front of the first vehicle 131 and located downstream of the work train 130 in this direction of circulation F2 ;
• a cutting step of the old rail 21, in particular the old junction rail 211 (see the Figure 5C ) thereby creating a discontinuity in the railway track 20 in a position spanning the discontinuity of the railway track 20 by the vehicle 132 carrying out the neutralization heating or cooling, the dismantling of the old rails 21 and the laying of the long new rails 22 as the train travels in the direction of travel F2 ;
• a heating or cooling step for neutralizing the end portion 221' of the first long new rail 221 comprising the end 221' to which the end 211' of the old junction rail 211 must be connected;
• after laying at least part of the first long new rail 221 on the sleepers 23 at the end 211' of the old junction rail 211, a step of temporary end-to-end connection of the end 211' of the old junction rail 211 with the end 221' of the first long new rail 221 by a temporary connection device 30 such as a fishplate or a rail puller (see Figure 5D ), guaranteeing the passage of bogies 101 and allowing an end-to-end and ideally neutral position to be maintained, despite possible variations in outside temperature;
• when the work train 100 has passed the temporary connection device 30, a permanent connection step, for example of welding, preferably aluminothermic, of the two connected ends 211', 221' followed by a step of removing the temporary connection device 30.

In a particular configuration, the heating or cooling of the end portion 211' of the old junction rail 211 upstream of its end 211' before cutting the rail can be ensured by at least one of the neutralization heating or cooling means 111 , and/or by all or part of the means 112, 113, 114 for maintaining and/or correcting the reference temperature. In the latter case, the neutralization heating or cooling means 111 can preferably be activated only from the step of neutralizing the end portion 221' of the first of the long new rails 221 at the reference temperature. The advantage of using only all or part of the means 112, 113, 114 for maintaining and/or correcting the reference temperature is that at this location, the old junction rails 211 are laid on the sleepers 23 and the use of the neutralization means 111 such as induction heating could damage the fasteners of the old rails which are, like the rails, also metallic. The maintenance and/or correction heating 112, 113, 114 is less powerful than the induction heating 111 and avoids damaging the fasteners. This is simpler to implement than using a means of varying the power of the neutralization means 111 , in particular induction heating, which would make the equipment more expensive and more complex. The heating or cooling of the end portion 211' of the old junction rail 211 is preferably carried out over a distance greater than the area over which the fasteners are dismantled (see Figure 5B ).

• une étape de chauffage ou de refroidissement de neutralisation à la température de référence d'une portion d'extrémité 222' d'un dernier des longs rails nouveaux 222, la portion d'extrémité comportant l'extrémité 222' du dernier long rail nouveau 222 à laquelle doit être raccordée l'ancienne voie ferrée 20 (voir la figure 6B) ;
• une étape de coupe du rail ancien 21 définissant une extrémité 212' d'un rail ancien de jonction 212 (voir la figure 6C) ;
• une étape de raccordement temporaire bout à bout de l'extrémité 222' du dernier long rail nouveau 222 avec l'extrémité 212' du rail ancien de jonction 212 correspondant par au moins un dispositif de raccordement temporaire 30 tel qu'une éclisse ou un tire-rail (voir la figure 6D) qui permet soit aux rails de l'allonger librement mais pas de se rétracter dans le cas de l'utilisation du chauffage soit de se rétracter librement mais pas de s'allonger dans le cas de l'utilisation d'un refroidissement, et ainsi maintenir une position neutre malgré d'éventuelles variations de température extérieure ;
• une étape de chauffage ou de refroidissement de neutralisation d'une portion d'extrémité 212' du rail ancien de jonction 212 située en amont de son extrémité 212' à laquelle doit être raccordée la portion d'extrémité 222' du dernier long rail nouveau 222, par rapport au deuxième sens de circulation F2 (voir la figure 6D), la portion d'extrémité 212' du rail ancien de jonction 212 comportant l'extrémité 212' du rail ancien de jonction à laquelle doit être raccordée la portion d'extrémité du dernier long rail nouveau 222 : cette étape de chauffage ou de refroidissement est de préférence mise en oeuvre par les moyens de maintien et/ou de correction 113, 114, 112 de la température de référence, plutôt que par les moyens de chauffage ou de refroidissement de neutralisation 111, le chauffage ou refroidissement de la portion d'extrémité 212' du rail ancien de jonction 212 étant de préférence effectué sur une distance supérieure à la zone sur laquelle les attaches sont démontées (voir la figure 6E) ;
• lorsque le train de travaux 100 a dépassé le dispositif de raccordement temporaire 30, une étape de raccordement permanent, par exemple de soudage, par exemple aluminothermique, des deux extrémités raccordées 212', 222' suivie d'une étape de retrait du dispositif de raccordement temporaire 30.

The second phase B also includes a final phase corresponding to the clearance of the stages of laying the long new rails 22 and dismantling the old rails 21 by the works train 100 to finalize the renewal. This final phase is illustrated in detail on the Figures 6A, 6B, 6C, 6D, 6E and 6F , and includes in particular, but not exclusively, the following steps, preferably for each of the two parallel rails at the same level of the railway track 20 :

• a neutralization heating or cooling step at the reference temperature of an end portion 222' of a last of the long new rails 222, the end portion comprising the end 222' of the last long new rail 222 to which the old railway track 20 is to be connected (see Figure 6B ) ;
• a cutting step of the old rail 21 defining an end 212' of an old junction rail 212 (see the Figure 6C ) ;
• a step of temporary end-to-end connection of the end 222' of the last long new rail 222 with the end 212' of the corresponding old junction rail 212 by at least one temporary connection device 30 such as a fishplate or a rail puller (see the Figure 6D ) which allows either the rails to extend freely but not to retract in the case of using heating or to retract freely but not to extend in the case of using cooling, and thus maintain a neutral position despite possible variations in the outside temperature;
• a heating or cooling step for neutralizing an end portion 212' of the old junction rail 212 located upstream of its end 212' to which the end portion 222' of the last long new rail 222 must be connected, relative to the second direction of circulation F2 (see the Figure 6D ), the end portion 212' of the old junction rail 212 comprising the end 212' of the old junction rail to which the end portion of the last long new rail 222 must be connected: this heating or cooling step is preferably implemented by the means 113, 114, 112 for maintaining and/or correcting the reference temperature, rather than by the neutralization heating or cooling means 111, the heating or cooling of the end portion 212' of the old junction rail 212 preferably being carried out over a distance greater than the area over which the fasteners are dismantled (see Figure 6E ) ;
• when the work train 100 has passed the temporary connection device 30, a permanent connection step, for example welding, for example aluminothermic, of the two connected ends 212', 222' followed by a step of removing the temporary connection device 30.

• un poste de travail 102 disposé sur une partie avant de la rame de travaux 130, ici en amont du troisième véhicule 133 dans le sens de la marche F2, est configuré pour retirer les attaches des rails qui les fixe aux traverses 23 de sorte qu'une portion détachée P1 de voie ferrée 20 n'est plus fixée par les attaches ;
• un poste de travail 103, porté par le troisième véhicule 133 et disposé en aval du poste de travail 102 de retrait des attaches, est configuré pour ramasser les attaches retirées ;
• un poste de travail 104, porté par le deuxième véhicule 132 et disposé en aval du poste de travail 103 de ramassage des attaches, est configuré pour démonter des anciennes semelles, généralement en caoutchouc, qui se placent entre la traverse et le dessous du rail, ces semelles ayant pour rôle d'amortir une partie des vibrations et de permettre le cheminement longitudinal du rail sans endommager la traverse 23 ;
• un poste de travail 105, porté par le deuxième véhicule 132 et disposé en aval du poste de travail 104 de démontage des anciennes semelles et en amont des moyens de neutralisations 111, est configuré pour déposer des nouvelles semelles sur les traverses 23 sur lesquelles vont venir reposer les longs rails nouveaux 22 ;
• un poste de travail 106, porté par le premier véhicule 131 et disposé en aval des moyens de maintien et/ou de correction 113 de la température de référence situés au niveau de la zone Z3, est configuré pour ramasser les anciennes semelles démontées par le poste de travail 104 ;
• un poste de travail 107, porté par le premier véhicule 131 et disposé en aval du poste de travail 106 de ramassage des anciennes semelles, configuré pour mettre en place les attaches ; et
• un poste de travail 108, porté par le premier véhicule 131 et disposé en aval poste de travail 107 de mise en place des attaches, configuré pour fixer les attaches des rails et ainsi fixer lesdits rails aux traverses 23, de sorte qu'une portion attachée P2 de la voie ferrée 20 est bloquée par les attaches.

Throughout the progress of work train 130, following the second direction of circulation F2 :

• a work station 102 arranged on a front part of the work train 130, here upstream of the third vehicle 133 in the direction of travel F2, is configured to remove the rail fasteners which fix them to the sleepers 23 so that a detached portion P1 of railway track 20 is no longer fixed by the fasteners;
• a work station 103, carried by the third vehicle 133 and arranged downstream of the fastener removal work station 102 , is configured to pick up the removed fasteners;
• a work station 104, carried by the second vehicle 132 and arranged downstream of the work station 103 for collecting the fasteners, is configured to dismantle old soles, generally made of rubber, which are placed between the sleeper and the underside of the rail, these soles having the role of absorbing part of the vibrations and of allowing the longitudinal path of the rail without damaging the sleeper 23 ;
• a work station 105, carried by the second vehicle 132 and arranged downstream of the work station 104 for dismantling the old soles and upstream of the neutralization means 111, is configured to place new soles on the sleepers 23 on which the long new rails 22 will rest;
• a work station 106, carried by the first vehicle 131 and arranged downstream of the means 113 for maintaining and/or correcting the reference temperature located at the level of the zone Z3, is configured to collect the old soles dismantled by the work station 104 ;
• a work station 107, carried by the first vehicle 131 and arranged downstream of the work station 106 for collecting the old soles, configured to put the fasteners in place; and
• a work station 108, carried by the first vehicle 131 and arranged downstream of the work station 107 for installing the fasteners, configured to fix the rail fasteners and thus fix said rails to the sleepers 23, such that an attached portion P2 of the railway track 20 is blocked by the fasteners.

In this way a new rail is neutralized in a detached state. Of course, these work stations can be substantially moved. As described, in a configuration with a third car 133, it is this car 133 which can ensure the removal of the fasteners from the rails. A step of collecting the fasteners is then preferably implemented directly after their removal. The long new rails 22 are for their part attached either with new fasteners, or with old fasteners previously removed and then collected, in order to ensure recycling of the fasteners if their condition allows it.

It should be noted that a workstation is understood to mean any workstation capable of receiving people to carry out manual operations and/or any equipment intended to carry out these operations automatically or semi-automatically.

Furthermore, during this second phase B , the removal of the fasteners, and therefore the subsequent blocking of the fasteners, is implemented from a downstream portion at the end 211' of the old junction rail 211 comprising the end 211' to which the end 221' of the first long new rail 221 must be connected and extends to an upstream portion at the end 212' of the old junction rail 212 comprising the end 212' to which the end 222' of the last long new rail 222 must be connected, with reference to the second direction of travel F2. In this way, the laying of the long new rails is done at a reference temperature, this laying being followed by operations aimed at subsequently fixing it in accordance with the predetermined reference temperature.

On the figure 7 a diagram is shown illustrating the operation of the railway convoy 10, in particular its progress along the railway track 20 : the abscissa indicating the evolution of time during the work and the ordinate indicating the position relative to the railway track 20. A first curve C100, higher here, corresponds to the progress of the works train 100 and a second curve C140, lower than the curve C100, corresponds to the progress of the railway vehicle 140 traveling independently and at a distance d from the works train 100.

During the first phase A, the works train 100 moves from a starting position X0 to an arrival position X1 along the railway track 20. During this movement following the first direction of travel F1, the works train 100 alternates between dynamic steps A1 , of unloading the long new rails 22 along the railway track 20, and static steps A3 , marking stages during which each long new rail is engaged in guide tunnels of the works train to ensure the proper unloading of these long new rails 22 along the railway track 20.

In parallel with the progress of the work train 100, the railway vehicle 140 moves in stages, alternating between static A2 stages of preparation for welding and dynamic A4 stages of movement from one end of two long new rails to another end following the first direction of travel F1.

Following the first phase A, the second phase B continues during which the work train 100 moves from the arrival position X1 to the departure position X0 along the railway track 20. During this movement in the second direction of travel F2, the work train 100 alternates between dynamic steps B3 of loading the old rails 21 onto the transport train 120 and static steps B5 marking levels during which the old rail 21 is cut during its loading so that it can be stored in a plurality of elementary sections on the transport train 120.

In such an embodiment, tests have shown that the work train 100 could move at a speed of 2500 m/h during the first phase A, and at a speed of 600 m/h during the second phase B , while being able to move following working radii of 250m and on slopes of 40%o. Such a method according to the invention also offers the advantage of being able to be implemented if necessary by leaving free any adjacent railway tracks which can therefore be circulated in complete safety.

In parallel with the progress of the work train 100 during this second phase B , the railway vehicle 140 moves in stages by alternating welding steps B2 and steps B4 of moving from one end of two long new rails to another following the second direction of travel F2. Steps B6 and B7 mark a movement of the welding machine 140 and the work train 100, respectively, in the continuity of its progress and beyond the starting position X0 in order to guarantee the welding between the two connected ends 212', 222' at the end of the worksite. The initial phases B1 ( Figures 5A to 5F ) and final B4 ( Figures 6A to 6F ) of the second phase B are indicated by steps, which is a simplification given the very low speed of movement of the work train 100 during these two phases A and B. Furthermore, such a method makes it possible to simply and relatively quickly implement the operations of electric welding of the LRS rails, the dismantling and reassembly of the rail fasteners, and the neutralization of the rails.

Naturally, the invention is described in the foregoing by way of example. It is understood that a person skilled in the art is able to carry out different variant embodiments of the invention without departing from the scope of the invention.

For example, the composition of the work train may be different. The work train may consist of only two cars as illustrated in the figures 5 And 6 or three cars as shown in the figures 1, 2 , 3 and 4 . More specifically, the work train can be configured to work without the third work vehicle 133 of the work train 130. In such a configuration, the old track fasteners can be dismantled with hand tools upstream of the railway convoy, with reference to the second direction of travel F2,

Furthermore, the rails can be renewed in parallel two by two so as to renew the entire railway track during the operations, and/or successively the along one side only of the railway track so as to renew the rails of a single row. Indeed, it can be envisaged that only successive rails on one side of the railway track are renewed, which can be interesting on sections of railway track such as curved sections. In other words, the initial and/or final laying processes can be implemented, as for renewal, on one row of rails of the railway track or simultaneously on the two parallel rows of rails of the railway track.

In an alternative or complementary configuration, the neutralization may be carried out otherwise than by heating or cooling, by mechanical constraints likely to cause the rail portions to stretch corresponding to their expansion at this reference temperature. The reference state then corresponds to a given expansion state as a reference, itself corresponding to a state of the rail portion if it were subjected to this reference temperature.

It is also possible to envisage that the first and second phases A and B are implemented spaced out in time: the first phase A can be implemented one night, and the second phase B can be implemented the following night.

As for the dismantling of the old rails, instead of being loaded onto the transport train, the old rails could also be unloaded along the railway track from their position on the sleepers.

Bogies can also be formed by any type of wheel set.

Such a rail convoy is particularly interesting in that it allows for the renewal of a railway track, offering the shortest possible immobilization of the railway track to reduce the duration of the construction site, while guaranteeing good safety of the railway track laid. Of course, it is also possible to use such a rail convoy for operations that do not involve all the stages. The rail convoy can be used to only transport and unload the long new rails along the railway track from the transport train, either outside of the railway track, either inside, with an optional welding operation and installation of the roller supports.

Claims (9)

1. Initial method for laying new long rails (22) of a railway track (20) by means of a work train (100) travelling in a direction of travel (F2), the initial method being intended to be implemented during a process for replacing old rails (21) of the railway track (20) of the type comprising a phase (B) during which the new long rails (22) are laid and subsequently fastened to a fixed structure (23) of the railway track (20) when the work train is travelling in said direction of travel (F2), the initial laying method comprising:

   - a step of laying at least one portion of a first of the new long rails (221) on the fixed structure (23) at at least one end (211') of an old joining rail (211);

   - a temporary end-to-end connection step for connecting the end (211') of the old joining rail (211) to at least one end (221') of the first new long rail (221) by means of at least one temporary connection device (30);

   - a step of permanent connection, for example by welding, of the two connected ends of the old joining rail (211) and the first new long rail (221);

   - prior to the laying step, a step of heating or cooling, for neutralizing to the reference temperature, at least one end portion (221') of the first new long rail (221), the end portion comprising the end (221') of the first new long rail (221) to which the end (211') of the old joining rail (211) is required to be connected.
2. Initial method for laying rails according to claim 1, characterized in that it comprises a step of neutralizing, preferably by heating or cooling, an end portion of the old joining rail (211) comprising the end (211') of the old joining rail (211) to which the end portion (221') of the first new long rail is required to be connected.
3. Initial method for laying rails according to either claim 1 or claim 2, characterized in that the step of heating or cooling for neutralizing the end portion of the old joining rail is performed by heat transfer or insulation means which preferably comprise an infrared radiation source for heating said end portion of the old joining rail to the reference temperature.
4. Initial method for laying rails according to any of the preceding claims, characterized in that, prior to the step of temporary end-to-end connection of the end (211') of the old joining rail (211) to the end (221') of the first new long rail (221) by the temporary connection device (30), a step of cutting the old joining rail (211) is performed, in order to form the end (211') of the old joining rail (211) which is to be connected.
5. Initial method for laying rails according to any of the preceding claims, characterized in that the temporary connection device (30) comprises at least one fishplate or rail driftpin.
6. Initial method for laying rails according to any of the preceding claims, characterized in that, prior to or following the step of temporary end-to-end connection of the end (211') of the old joining rail (211) to the end (221') of the first new long rail (221) by the temporary connection device (30), said ends (211', 221') undergoing a preparation step in view of the permanent connection step, for example a step of abrasive machining.
7. Final method for laying new long rails (22) of a railway track (20) by means of a work train (100) travelling in a direction of travel (F2), the final method being intended to be implemented during a process for replacing old rails (21) of the railway track (20) of the type comprising a phase (B) during which the new long rails (22) are laid and subsequently fastened to a fixed structure (23) of the railway track (20) when the work train is travelling in said direction of travel (F2), the final laying method comprising:

   - a step of laying at least one portion of a last of the new long rails (222) on the fixed structure (23) at at least one end (212') of an old joining rail (212);

   - a temporary end-to-end connection step for connecting an end (222') of the last new long rail (222) to at least the end (212') of the old joining rail (212) by means of at least one temporary connection device (30);

   - a step of permanent connection, for example by welding, of the two connected ends of the old joining rail (212) and the last new long rail (222);

   - prior to the laying step, a step of heating or cooling, for neutralizing to the reference temperature, at least one end portion (222') of the last new long rail (222), the end portion comprising the end (222') of the last new long rail (222) to which the end (212') of the old joining rail (212) is required to be connected.
8. Final method according to claim 7, characterized in that it comprises a step of neutralizing, preferably by heating or cooling, an end portion (212') of the old joining rail (212) comprising the end (212') of the old joining rail to which the end portion of the last new long rail (222) is required to be connected.
9. Method for replacing old rails (21) of a railway track (20) of the type comprising a phase (B) during which the new long rails (22) are laid and subsequently fastened to a fixed structure (23) of the railway track (20) by a work train (100) travelling in a direction of travel (F2), the replacement method being characterized in that the phase (B) is initiated by the initial method for laying new long rails (22) according to any of claims 1 to 6, and/or finalized by the final method for laying new long rails (22) according to either claim 7 or claim 8.

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