WORK TRAIN FOR THE RENEWAL OF THE BALLAST AND SLEEPERS ON A SECTION OF TRACK

Abstract

Work train (100) for the renewal of ballast and sleepers on a section of track (1A, 1B), said work train comprising: - a suction device (10) for the old ballast, - a means of storing (20) the sleepers (2a, 2b), - a main wagon (30) comprising, from front to rear in the direction of travel: - a ballast regulator (340) comprising at least one regulator (341) configured to push the unsuctioned old ballast towards the center of the track, - a trolley (310), movable in translation, comprising an articulated arm (311) configured to remove the old sleepers from the track and lay new sleepers (2b), - a sleeper uncoupling / coupling station (320) for the rails (3), - a track ballasting hopper (330), - a means of storing new ballast (4b) as well as a ballasted conveyor (60). Figure for the abbreviation: Figure 5

Description

Title of the invention: WORK TRAIN FOR THE RENEWAL OF BALLAST AND SLEEPERS OF A PORTION OF TRACK Technical field of the invention

[0001] The present invention relates to a work train for renewing the ballast and sleepers of a portion of track. The work train is particularly intended to operate in an underground environment such as a metro network. The track may in particular be for rolling stock fitted with iron bearings or pneumatic bearings. The invention also relates to the method for renewing the ballast and sleepers implemented by the aforementioned work train. Technological background

[0002] The metro system implemented in large cities generally constitutes a primarily underground network. Different types of metro can coexist on the same network, which can thus include metro lines whose rolling stock is equipped with iron bearings and metro lines whose rolling stock is equipped with pneumatic bearings. This is the case, for example, of the Paris metro in France.

[0003] Conventionally, when the rolling stock is equipped with iron bearings, it rolls on tracks IA called irons as shown in [Fig.l]. These tracks IA typically comprise sleepers 2, made of wood or concrete, positioned perpendicular to rails 3, which are fixed to the sleepers 2 by lag screws 5, and a ballast 4 which allows the anchoring of the track IA. The metro network being generally electric, a side rail 6 is present to electrically supply the rolling stock.

[0004] When the rolling stock is equipped with pneumatic bearings, it rolls on tracks called IB tires as shown in [Fig.2]. These IB tracks typically comprise sleepers 2 on which are fixed, by means of lag screws 5, rolling tracks 7 on which the pneumatic wheels roll, and lateral guide bars 8 allowing the guidance of horizontal pneumatic wheels and also ensuring the electrical supply of the rolling stock. The 3-iron rails remain present even on an IB tire track. The ballast 4, allowing the anchoring of the IB tire track, is arranged under and between the sleepers 2.

[0005] By their configuration, the so-called tire tracks are wider than the so-called iron tracks and consequently have sleepers that are generally longer than the sleepers of a railway track.

[0006] Faced with the aging and wear of the network and in particular of the various tracks, it becomes necessary for operators to regenerate their networks. In order to maintain a correct condition of the network, certain components must be renewed. Thus, the sleepers and the ballast appear to be those that must be replaced massively. Indeed, the metro lines being essentially underground, they suffer from various problems linked in particular to water infiltrations which tend to damage the wooden sleepers, which rot and disintegrate, but also linked to the punctual injections of concrete intended to reinforce certain vaults which have left solid and massive residues in the track which distort the latter and pose problems of differential settlement. Finally, the attrition of the ballast due to the numerous commercial circulations of the rolling stock as well as to pollution makes its replacement necessary.

[0007] The renewal of ballast and sleepers is carried out industrially for the tracks of so-called "main line" surface trains on the national network. It then uses large, heavily mechanized work trains which make it possible to achieve outputs close to 1000 meters of renewed track for interventions lasting 4 to 5 hours.

[0008] However, these work trains are poorly suited to the specific constraints of the metro network. Indeed, underground infrastructure is often built in small gauges which make access difficult and directly impact the dimensions of the work trains that can operate there. The track curves, often tight, also make maneuvers complicated. In addition, the intensive operation of the network severely limits the time allowed for work, often by a few hours at night.

[0009] It should also be noted that these work trains traditionally used on the surface are not designed to deal with tire tracks which, as mentioned previously, have different characteristics compared to conventional railway tracks.

[0010] To deal with the renewal of the railway tracks of metro lines, mechanized solutions have already been developed in the past. They were based on the use of a bucket-type ballast stripper specially designed for replacing ballast and on lorries for handling sleepers. In particular, they allowed the replacement of ballast and sleepers of 60 meters of track over a period of approximately 5 hours, by dealing with small areas of 5 meters renewed end to end without touching the rails. In other words, the method used was based on a one-off deconsolidation of the track, thus avoiding having a significant length of track without ballast or difficulties in surrendering, i.e. freeing the track, in the event of a breakdown.

[0011] However, these solutions had drawbacks. Indeed, when the ballast was removed, the track was wedged using wooden blocks and the operators intervened directly in the excavation, that is to say in a free volume under the rails formed by the removal of the ballast, to secure the sleepers to the lorries. This represented difficult working conditions and compromised the safety of the operators. Another drawback was the fact that these solutions were not designed for the renewal of the tire tracks, the presence of the tracks and the guide bars being a hindrance.

[0012] Another solution implemented to renew the ballast and sleepers of underground metro networks is based on the scheduling of one-off projects during which work teams intervene with light means. A work train, generally present on the track adjacent to the one benefiting from the ballast and sleeper renewal, transports the new ballast and the new sleepers. This work train can also be equipped with a mechanical shovel which moves on the wagons of the work train and which helps to remove the ballast as well as to load it onto the work train.

[0013] This type of solution also has disadvantages, which mainly lie in the low yield of the renewal of the ballast and sleepers, which is around 5 meters for 3 hours of intervention, due to the fact that most of the work remains manual and not very mechanized. This level of yield does not allow the maintenance of a network in good condition because the latter then wears out faster than it is regenerated.

[0014] Also, an objective of the invention is to propose a work train which does not have at least one of the aforementioned drawbacks.

[0015] Another objective of the invention is to propose a work train making it possible to achieve a significantly improved average efficiency in renewing ballast and sleepers, both on railways and on tyre tracks.

[0016] Another objective of the invention is to propose a work train ensuring improved safety for operators as well as high reliability. Summary of the invention

[0017] A work train is therefore proposed for the renewal of ballast and sleepers of a portion of track, this portion of track comprising at least one pair of rails, sleepers, called old, and the ballast, called old, this work train comprising: - a device for suctioning old track ballast and a means of storing associated old ballast, - a means of storing sleepers, - a main wagon fitted with two bogies between which extend two parallel beams, these beams having an overall omega shape and each comprising at each end a lower part linked to a bogie and an upper part, the main wagon comprising, from front to rear in the direction of travel: - a leveling station comprising at least one leveler mounted under the two beams, this leveler being configured to fold back, by means of at least one rotating arm, the old ballast not sucked up by the suction device, located under each end of a sleeper, towards the center of the track, so as to form a excavation bottom under the track, - a trolley mounted so as to move in translation on and along the beams, the trolley comprising an articulated arm equipped with a rotating gripping element so that the articulated arm has access to the track by passing between the two beams in order, on the one hand, to remove the old sleepers from the track and, on the other hand, to install new sleepers, - a sleeper detachment / connection station suspended from the two beams and configured to move along the two beams, said sleeper detachment / connection station being arranged so that the articulated arm has access to the track, - a track ballast hopper, - a means of storing new ballast and a ballast conveyor extending from the means of storing new ballast to the ballast hopper.

[0018] Thus, thanks to the invention, an improvement in the efficiency of the ballast and sleeper renewal operations on a section of track is ensured. Indeed, the centralization on a single wagon of the various tools necessary for renewal allows a rationalization of the operations, that is to say an optimization of these operations both in their sequence and in their duration. On the one hand, the sleeper detachment / attachment station facilitates the work of the operators to remove the fixings of the old sleepers and fix the new ones by having them intervene directly above the rails, and, on the other hand, the trolley with its articulated arm ensures the handling of the sleepers directly above the track, the articulated arm passing between the beams of the main wagon to have access to the track.In addition, the articulated arm allows the old sleepers to be handled directly to the dedicated sleeper storage facility and new sleepers to be retrieved for installation.

[0019] The work train, according to the invention, may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another: - the two beams have a spacing between them taken at the level of the upper part which is less than a spacing between the beams taken at the level of a lower part; - the main wagon includes a control cabin for the trolley and the articulated arm, suspended between the two beams, so that in use an operator has a clear view of the track from the control cabin; - the main wagon includes an articulated support for a suction head of the old ballast suction device; - the station for disconnecting / connecting the sleepers to the rails has two seats, each suspended from one of the two beams above a rail and configured to translate perpendicularly to the two beams; - the regulator is configured to be mobile in axial and lateral translation relative to the beams; - at least one arm of the regulator has a width at most equal to a spacing between two consecutive crosspieces; - the regulator is designed to rest, when in use, on the track rails; - the main wagon comprises a compactor equipped with at least one vibrating plate for crushing and distributing the new ballast between at least two new sleepers, said compactor being suspended from the two beams, said compactor being movable in axial and lateral translation relative to the beams; - the work train has batteries for an independent power supply of the work train.

[0020] The invention also relates to a method for renewing ballast and sleepers of a portion of track implemented by a works train as described above, the method comprising: - A) a priming phase comprising the following steps: Al) sucking up the old ballast between at least the rails of the track by means of the suction device so as to form a free volume under the rails, this free volume having a length, defined according to the orientation of the rails, at least equal to the length of an old or new sleeper; A2) using the leveler, fold back into the free volume the old, unsucked ballast towards the center of the track and level the old, unsucked ballast under the track to form a substantially flat and uniform excavation bottom; A3) separating a plurality of old sleepers from the track rails so as to form an opening defined in the plane of the rails and opening into the free volume and having a length at least equal to the length of an old or new sleeper, said old sleepers falling onto the bottom of the excavation once separated; A4) for each old, detached sleeper, grasp and turn the old, detached sleeper in the free space using the articulated arm, then remove the said old, detached sleeper through the opening before storing the said old, detached sleeper in the sleeper storage means; - B) a nominal phase comprising the following steps: Bl) using the articulated arm, insert through the opening and then, after rotation in the free volume, secure a new sleeper to the track rails in place of an old sleeper removed, said new sleeper having been recovered from the sleeper storage means; B2) ballast the new ballast through the ballast hopper so as to partially fill the free volume, said new ballast having been conveyed from the new ballast storage means to said hopper by a conveyor; B3) suck up the old ballast between at least the rails and two new old sleepers still attached to the rails; B4) fold back the old, unvaccinated ballast as in step A2); B5) detaching a new old sleeper from the track rails so that the length of the opening remains substantially equal to that formed in step A3), said new old sleeper falling onto the bottom of the excavation once detached; B6) grasp and turn the new, detached, old sleeper in the free space using the articulated arm, then remove the new, detached, old sleeper through the opening before storing the new, detached, old sleeper in the sleeper storage means; and B7) repeat steps Bl) to B6) until the ballast and sleepers of the predefined portion of the track are renewed.

[0021] The method according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another: - the process includes, after the nominal phase B), a finishing phase C) which comprises the following steps: Cl) using the articulated arm, insert through the opening and then, after rotation in the free volume, place a plurality of sleepers on the bottom of the excavation new, the plurality of new sleepers being equal in number to the plurality of old sleepers from step A3), said new sleepers having been recovered from the sleeper storage means; C2) secure each new sleeper of the plurality of new sleepers to the rails of the track so as to close the opening leading into the free volume; and C3) ballast the new ballast on the track so as to fill the free volume - in steps Al) and B3), the old ballast is sucked out from under the old sleepers to a depth of between 20 cm and 50 cm; - prior to steps Al) and B3), the old ballast is moistened using a watering device; - the bottom of the excavation is located under the sleepers at a depth of between 20 cm and 30 cm; - each of the rotations of steps A4) and B6) is carried out so that the old sleeper is positioned substantially in the axis of the rails; - after ballasting, a stage of compacting the new ballast is carried out by a compactor between the new joined sleepers; - each step of the process is powered by batteries. Brief description of the figures

[0022] The invention will be better understood with the aid of the following description, given solely by way of example and with reference to the appended drawings in which:

[0023] [Fig.l] represents a schematic sectional view of a track for rolling stock fitted with iron bearings,

[0024] [Fig. 2] represents a schematic sectional view of a track for rolling stock fitted with pneumatic bearings,

[0025] [Fig. 3] represents a schematic side view of an embodiment according to the invention,

[0026] [Fig. 4] represents a schematic side view of an alternative embodiment according to the invention,

[0027] [Fig.5] represents a schematic perspective view of the embodiment of [Fig.4],

[0028] [Fig.6] represents a schematic perspective view of a detail of the embodiment of [Fig.5], in particular the carriage,

[0029] [Fig.7] represents a schematic perspective view of a detail of the embodiment of [Fig.5], in particular the carriage after rotation and removal of an old sleeper from the track,

[0030] [Fig.8] represents a schematic cross-sectional view of the embodiment of [Fig.4], in particular the sleeper detachment / coupling station,

[0031] [Fig.9] shows another schematic view of the sleeper decoupling / coupling station of [Fig.8], when a sleeper is placed on the bottom of the excavation,

[0032] [Fig. 10] shows another schematic view of the sleeper decoupling / coupling station of [Fig.8], when a sleeper is caught by the articulated arm to be removed / inserted from / to the track,

[0033] [Fig. 11] shows a schematic cross-sectional view of the embodiment of [Fig. 4], in particular the suction device,

[0034] [Fig. 12] shows a schematic cross-sectional view of the embodiment of [Fig. 4], in particular the adjustment station,

[0035] [Fig. 13] represents a schematic perspective view of a detail of the embodiment of [Fig. 5], in particular the ballast hopper and the compactor,

[0036] [Fig. 14] shows a schematic cross-sectional view of [Fig.4], in particular the ballast hopper,

[0037] [Fig. 15] shows a schematic cross-sectional view of [Fig.4], in particular the compactor,

[0038] [Fig. 16] represents a top view of the main wagon according to the invention, without the trolley being shown, in the case of a curved portion of track,

[0039] [Fig. 17] represents a block diagram of the method for renewing ballast and sleepers of a portion of track according to the invention,

[0040] [Fig. 18A] represents a schematic view of the first part of a kinematic breakdown of the method according to the invention applied to a tire track, and

[0041] [Fig.l8B] represents a schematic view of the second part of the kinematic breakdown of [Fig.l8A]. Detailed description of the invention

[0042] With reference to Figures 1 and 2, already described in the above, there are several types of tracks for rolling stock in a metro network: IA rail tracks and IB tire tracks. In the following, reference will be made for convenience to track IA, IB since the invention is suitable for use on these two types of tracks as detailed below. Still for convenience, the following will also refer to the “rails 3 and other elements”. By this designation, it is understood that reference is made to the side rails 6, the running tracks 7 and / or the guide bars 8.

[0043] We are now interested in figures 3 to 15 which illustrate a works train 100 for the renewal of a ballast 4 and the sleepers 2 of a portion of track IA, IB according to the invention and details concerning different aspects of this works train 100.

[0044] In situation, the work train 100 according to the invention is brought onto a portion of track IA, IB composed of at least one pair of rails 3, sleepers 2a, called old, and ballast 4a, called old. It is understood that the old sleepers 2a and the old ballast 4a must be renewed and changed respectively by new sleepers 2b and new ballast 4b.

[0045] The work train 100 comprises a suction device 10 for the old ballast of the track IA, IB as well as an associated storage means 50, a storage means 20 for the sleepers 2a, 2b and a storage means 40 for new ballast 4b.

[0046] The suction of the suction device 10 can for example be carried out by means of one or more fans or one or more vacuum pumps. A vacuum pump has the advantage of being able to maintain a substantially constant suction.

[0047] The work train 100 also comprises a main wagon 30 provided with two bogies 31 between which extend two beams 32 parallel to each other. The beams 32 have an overall omega shape. Each beam 32 thus comprises, at each end, a lower part 34, 34', linked to one of the bogies 31, and an upper part 35.

[0048] Advantageously, the two beams 32 have a spacing between them taken at the level of the upper part 35 which is less than a spacing between the beams 32 taken at the level of a lower part 34, 34'. It is understood that this spacing is a lateral spacing. This allows the main wagon 30 to be able to cross the narrowest parts of a tunnel of the metro network on which the works train is intended to be used.

[0049] The main wagon 30 comprises, from front to rear in the direction of travel, a leveling station 340, a trolley 310, a station 320 for disconnecting / connecting the sleepers 2a, 2b to the rails 3 and other elements and a hopper 330 for ballast of the track IA, IB.

[0050] A ballast conveyor 60 also extends from the storage means 40 for the new ballast 4b to the ballast hopper 330 of the main wagon 30. We are talking here about a conveyor 60 in general which can be composed of a multitude of conveyors placed in series.

[0051] We now look in more detail at the main car 30.

[0052] The trolley 310 of the main wagon 30 comprises an articulated arm 311 mounted on and between the two beams 32 so that the articulated arm 311 has access to the track IA, IB by passing between the two beams 32 to, on the one hand, remove the old sleepers 2a from the track IA, IB and, on the other hand, lay new sleepers 2b. To grip the sleepers 2a, 2b, the articulated arm 311 is provided with a rotating gripping element 314.

[0053] The carriage 310 is mounted to move in translation on and along the beams 32. It is understood that the carriage 310 is mounted in the upper part 35 of the beams 32. For example, the carriage 310 can be located on rails 33 mounted on and along the beams 32 so that the carriage 310, with the articulated arm 311, can move on these rails 33.

[0054] The articulated arm 311 can furthermore be directly controlled from the carriage 310, as shown in [Fig.3], where an operator is installed on the carriage 310, therefore on the beams 32.

[0055] However, this configuration is not the most optimal insofar as the operator's field of vision, in particular between the two beams 32, is obstructed by the articulated arm 311. In addition, since the operator is located high up relative to the track IA, IB, precise manipulation of the sleepers 2a, 2b may prove difficult.

[0056] Also, advantageously, the main wagon 30 comprises a control cabin 312 for the trolley 310 and the articulated arm 311. This control cabin 312 is suspended between the two beams 32 above the track IA, IB so that in use an operator has a clear view of the track IA, IB from the control cabin 312, as shown in Figures 4 to 7. It is understood that the articulated arm 311 is, in such a case, controlled remotely from the control cabin 312. From this control cabin 312, the operator can also control the movement of the trolley 310 equipped with the articulated arm 311 along the beams 32.

[0057] The control cabin 312 is advantageously located downstream of the adjustment station 340 and upstream of the decoupling / coupling station 320.

[0058] Alternatively, an operator may control the trolley 310 and the articulated arm 311 with a remote control, such as a radio control, while being next to the main wagon 30.

[0059] With reference to [Fig.8], the station 320 for disconnecting / connecting the sleepers 2a, 2b to the rails 3 and other elements is suspended from the two beams 32, above the rails 3, and is configured to translate along the two beams 32. It is understood that the disconnecting / connecting station 320 is suspended from the upper part 35 of the beams 32. A sliding connection 321 can, for example, allow the disconnecting / connecting station 320 to translate along the two beams 32. The disconnecting / connecting station 320 can also be suspended from one or more rails fixed to the beams 32. It is preferred that the movement of the disconnecting / connecting station 320 along the beams 32 is limited on one side by the leveling station 340 and on the other by hopper 330.The movement of the decoupling / coupling station 320 can be limited on one side by the control cabin 312 when the latter is present and on the other side by the hopper 330. The decoupling / coupling station 320 is further designed so that the articulated arm 311 has access to the track IA, IB.

[0060] Advantageously, the decoupling / coupling station 320 comprises two seats 322, each suspended from one of the two beams 32 above a rail 3. Each seat is configured to translate along this beam 32 as indicated previously.

[0061] Advantageously, each of these seats 322 is configured to be able to translate perpendicularly to the beams 32, for example by means of a slide. In this way, the operator seated on a seat 322 of the uncoupling / coupling station 320 can adjust his position relative to the rails 3, side rails 6, running tracks 7 and / or guide bars 8 of the track IA, IB to facilitate the removal or placement of the lag screws 5 of the sleepers 2a, 2b. In addition, this also makes it possible to adjust his lateral position when the track IA, IB is curved, as shown in [Fig. 16], where an offset is observed between the beams 32 of the main wagon 30 and the track IA, IB.

[0062] With reference to [Fig. 11], the main wagon 30 may comprise, upstream of the regulating station 340, a mobile support 360 for a suction head 12 of the suction device 10 for the old ballast 4a, the suction head 12 then being connected by a flexible pipe 11 to the storage means 50 for the old ballast 4a. This mobile support 360 allows an operator to precisely control the suction head 12 of the suction device 10 for the old ballast 4a under the track IA, IB. The mobile support 360 can be controlled by the operator by means of a control unit 13.

[0063] The main wagon 30 may comprise, at the same level as the mobile support, a device 370 for watering the old ballast 4a, as visible in [Fig. 18A]. Watering the old ballast 4a with water makes it possible to dilute the pollution which over time has either clogged the old ballast 4A or made it compact. In other words, watering makes it possible to detach the grains of old ballast 4a from each other, or to decompact the old ballast 4a, which facilitates its suction by the suction device 10. This also makes it possible to facilitate the adjustment operation as described below.

[0064] Advantageously, the main wagon 30 may comprise a mechanical decompaction device, not shown, to ultimately improve the suction of the ballast. This device may, for example, be vibrating needles intended to be planted in the ballast 4a.

[0065] With reference to [Fig. 12], the main wagon 30 comprises, upstream of the uncoupling / coupling station 320 but downstream of the mobile support 360, when present, a leveling station 340. Leveling is understood to mean an operation consisting of leveling a ground so as to give it a regular surface. Also, this leveling station 340 comprises a leveler 341 mounted under the two beams 32. It is understood that the leveler is mounted under the upper part 35 of the beams 32.

[0066] The leveler 341 is configured to fold, by means of at least one arm 342 movable in rotation, the old ballast 4a not sucked up by the suction device 10, towards the center of the track IA, IB, so as to form under the track IA, IB an excavation bottom 91. This excavation bottom 91 is further arranged to be leveled, substantially flat and uniform. Preferably, the old ballast 4a folded down by the leveler 341 is that located under each end of an old sleeper 2a.

[0067] The regulating station 340 may comprise a control cabin 345 of the regulator 341 which is suspended between the two beams 32 above the track IA, IB so that in use an operator has a clear view of the track IA, IB, and in particular of the free volume 90 under the track IA, IB, from the control cabin 345. It is understood that the control cabin 345 is suspended from the upper part 35 of the beams 32.

[0068] Conventionally, the regulator 341 comprises a block 344 positioned transversely to the track IA, IB from which the motor block of the arm 342 is suspended, the latter being able to move laterally under the block 344.

[0069] Advantageously, the regulator 341, via the block 344, is, in use, at least supported on the rails 3 of the track IA, IB in order to increase its stability and transmit more force to the arm 342.

[0070] Advantageously, the regulator 341 is configured to be movable in axial and lateral translation relative to the beams 32. These translations are permitted by the presence of jacks for example, fixed between the regulator 341 and the beams 32 and / or along the beams 32. An axial translation makes it possible, among other things, to compensate for a variation in spacing, or travel, between the sleepers 2a, while a lateral translation, as described previously, is advantageous for compensating for the offset which is observed between the beams 32 of the main wagon 30 and the track IA, IB when this same track IA, IB is curved.

[0071] Advantageously, the arm 342 of the regulator has a width which is at most equal to the spacing existing between two consecutive old crosspieces 2a.

[0072] Furthermore, the arm 342 can be provided with “fingers” 343 designed to scrape and tear off more easily the old, unsucked ballast 4a which, over time, has become compact.

[0073] As a variant, not shown, the regulator 341 may comprise two arms 342, each located on one side and the other of the regulator 341.

[0074] As a variant, not shown, the adjustment station 340 may comprise two adjusters 341, placed one behind the other.

[0075] With reference to Figures 13 to 15, the main wagon 30 may also comprise, downstream of the hopper 330, a compactor 350 provided with at least one vibrating plate 351 for crushing and distributing the new ballast 4b, deposited by the hopper 330, between at least two new sleepers 2b. The compactor 350 is suspended from the two beams 32 of the main wagon 30. The compactor 350 may, alternatively, be suspended from a substructure of these same beams 32 which extends under the conveyor 60.

[0076] The compactor 350 is further configured to be movable in axial and lateral translation relative to the beams 32. The axial translations are enabled by rails or slides 352 fixed to the beams 32 while the lateral translations are enabled by the presence of jacks or slides for example. These translations have the same advantages as described previously for the regulator 341.

[0077] Like the compactor 350, the hopper 330 can be configured to be movable in axial and lateral translation relative to the beams 32. The axial translations are enabled by rails or slides 332 fixed to the beams 32 while the lateral translations are enabled by the presence of jacks or slides for example. These translations have the same advantages as described previously for the regulator 341.

[0078] Returning to Figures 3 to 5, the storage means 20 for the sleepers 2a, 2b may be a wagon located downstream, in the direction of travel, from the main wagon 30. The storage means 20 may comprise several racks 21 intended to receive the old sleepers 2a or new sleepers 2b, as well as an exchange zone 22 for the old sleepers 2a and new sleepers 2b. This exchange zone 22 is also accessible to the articulated arm 311 of the trolley 310. The articulated arm 311 places, for example, an old sleeper 2a removed in the exchange zone 22 before recovering a new sleeper 2b brought by a handling gantry 23 from one of the racks 21. The handling gantry 23 can be movable along the sleeper storage means 20 by being mounted on rails specific to the storage means 20, for example by being fixed to uprights of the wagon. In this way, the routing of the sleepers 2a, 2b from the racks 21 to the exchange zone 23 or vice versa is facilitated.

[0079] A part of the conveyor 60 is also located under the storage means 20 of the sleepers 2a, 2b to allow the routing of the new ballast 4b to the main wagon 30.

[0080] The storage means 40 for the new ballast 4b may be in the form of one or more wagons located downstream, depending on the direction of travel, from the storage means 20 for the sleepers 2a, 2b. The storage means 40 may comprise several hoppers containing new ballast 4b discharging onto the conveyor 60. It is understood that the conveyor 60 thus extends from the storage means 40 for the new ballast 4b to the ballast hopper 330 on the track 1A, 1B, passing through the storage means 20 for the sleepers 2a, 2b.

[0081] The work train 100 may include batteries, not shown, for an autonomous power supply. This makes it possible to dispense with the electrical network coming from the side rails 6 or the guide bars 8 whose electrical supply is cut off during work. On the other hand, using an autonomous power supply has the advantage of emitting little pollution into the air, which limits the impact on the health of operators. This is not the case with diesel machines, for example.

[0082] The invention also relates to a method P for renewing ballast and sleepers of a portion of track IA, IB implemented by a works train 100 as described above.

[0083] The method P according to the invention comprises:

[0084] A) a priming phase comprising the following steps: Al) sucking up between at least the rails 3 and two sleepers 2a, 2b of the track IA, IB the old ballast 4a by means of the suction device 10 so as to form a free volume 90 under the rails 3, this free volume 90 having a length, defined according to the orientation of the rails 3, at least equal to a length of an old sleeper 2a or new sleeper 2b; A2) folding back into the free volume 90, by means of the leveler 341, the old ballast 4a not sucked up towards the center of the track IA, IB and leveling the old ballast 4a not sucked up under the track IA, IB to form a substantially flat and uniform excavation bottom 91; A3) separating a plurality of old sleepers 2a from the rails 3 of the track IA, IB so as to form an opening 92 defined in the plane of the rails 3 and opening into the free volume 90 and having a length at least equal to the length of an old sleeper 2a or new sleeper 2b, the old sleepers 2a falling onto the excavation bottom 91 once separated; and A4) for each old crosspiece 2a detached, grasp and turn in the free volume 90 the old crosspiece 2a detached by means of the articulated arm 311, then remove the old crosspiece 2a detached through the opening 92 before storing the old crosspiece 2a detached in the storage means 20 of the crosspieces 2a, 2b,

[0085] B) a nominal phase comprising the following steps: Bl) by means of the articulated arm 311, insert through the opening 92 then, after rotation in the free volume 90, secure to the rails 3 of the track IA, IB a new sleeper 2b in place of an old sleeper 2a removed, the new sleeper 2b having been recovered in the storage means 20 of the sleepers 2a, 2b; B2) ballast the new ballast 4b through the ballast hopper 330 so as to partially fill the free volume 90, the new ballast 4b having been conveyed from the storage means 40 of the new ballast 4a to the hopper 330 by a conveyor 60; B3) suck up the old ballast 4a between at least rails 3 and two new old sleepers 2a still attached to rails 3; B4) fold back the old ballast 4a not sucked up as in step A2); B5) detaching a new old sleeper 2a from the rails 3 of the track IA, IB so that the length of the opening 92 remains substantially equal to that formed in step A3), the new old sleeper 2a falling onto the bottom of the excavation 91 once detached; B 6) grasp and turn in the free volume 90 the new old crosspiece 2a detached by means of the articulated arm 311, then remove the new old crosspiece 2a detached through the opening 92 before storing the new old crosspiece 2a detached in the storage means 20 of the crosspieces 2a, 2b; and B7) repeat steps Bl) to B6) until ballast 4 and sleepers 2 of the predefined portion of track IA, IB are renewed.

[0086] The steps of method P are detailed in the following, with reference to the block diagram of [Fig. 17] and the kinematic breakdown of figures 18A and 18B.

[0087] The method P comprises a start-up phase A) during which the route IA, IB is prepared to launch the work.

[0088] At a step P08, prior to step A1) or P10, the old ballast 4a can be moistened by means of a watering device 370 so as to make the old ballast 4a less compact thanks to the percolation of water in the old ballast 4a. This moistening of the old ballast 4a increases the separation of the ballast grains from each other and facilitates the following suction and / or adjustment steps, when implemented.

[0089] At a step P10, or step A1), the old ballast 4a at least located between the rails 3 of the track IA, IB is sucked up by means of the suction device 10. In this way, a free volume 90 is formed under the rails 3, as shown in [Fig.l 1]. This free volume 90 is arranged so as to have a length at least equal to the length of an old sleeper 2a or new sleeper 2b so that they can be maneuvered in the free volume 90. The length of the free volume 90 is understood to mean a dimension defined according to the orientation of the rails 3, that is to say extending substantially parallel to the rails 3.

[0090] In this step P10, the old ballast 4a can be sucked under the old sleepers 2a to a depth of between 20 cm and 60 cm to form the free volume 90.

[0091] At a step P11 or step A2), following step P10, a mechanical leveling ensures, by means of the leveler 341, a folding of the old ballast 4a not sucked up at step P10 towards the center of the track IA, 1B. The leveler 341 is inserted into the free volume 90 under the old sleepers 2a and the arm 342 of the leveler 341 is rotated on one side of the free volume 90, then on the other, to break the old ballast 4a not sucked up which has remained under the ends of the sleepers 2a and fold it towards the center of the track IA, 1B. In this way, the mechanical leveling ensures a leveling old ballast 4a not sucked under the track IA, IB to form a substantially flat and uniform excavation bottom 91, as shown in [Fig. 12]. In addition, it is ensured that the width of the free volume 90 is at least equal to the length of a sleeper 2a, 2b.

[0092] In this step PI 1, the excavation bottom 91 is located under the sleepers 2a, 2b at a depth of between 20 cm and 30 cm.

[0093] At this stage, part of the rails 3, and other elements, and of the sleepers 2a of the track portion IA, IB are in the air, that is to say they are not resting on any ballast.

[0094] In a step P12 or step A3), a plurality of old sleepers 2a are separated from the rails 3 and other elements of the track IA, IB by the operator(s) of the separation / separation station 320 so as to form an opening 92. This opening 92 is defined in the plane of the rails 3. The opening 92 also opens into the free volume 90. This opening 92 has a length at least equal to the length of an old sleeper 2a or new sleeper 2b, as shown in FIGS. 6 to 10 and 18. In this step, the lag screws 5 holding the old sleepers 2a to the rails 3 and other elements of the track IA, IB are removed. To facilitate the operation, the articulated arm 311 can be used to hold the old sleeper 2a in place, using its rotating gripping element 314 ([Fig.8]). The old sleeper 2a, once detached, then falls or is placed in the free volume 90, and preferably on the bottom of the excavation 91 ([Fig.9]).In the case where the distance separating two old sleepers 2a is less than the length of a sleeper 2a, 2b, it is necessary to separate several old sleepers 2a to form the opening 92 as described previously.

[0095] At a step P14 or step A4), each of the old sleepers 2a separated in the previous step is removed through the opening 92 formed in step P12. Beforehand, each old sleeper 2a separated will have performed a rotation, on a plane parallel to the plane of the rails 3, in the free volume 90 to find itself substantially in the axis of the rails 3. The rotation, which is generally 90°, is carried out using the articulated arm 311 ([Fig. 10] and 18A, B). It is understood that, in this configuration, it is necessary that, in order to pass through the opening 92, a sufficient number of old sleepers 2a have been separated in step P12. The articulated arm 311 extracts the old sleeper 2a through the opening 92 and lifts it, without being hindered by the decoupling / coupling station 320, between the two beams 32 of the main wagon 30 (figures 6 and 7) before storing it in the storage means 20 for the sleepers 2a, 2b.

[0096] In the example of figures 18A, 18B, once the old sleeper 2a has been extracted, the carriage 310 carrying the articulated arm 311 is maneuvered on the rails 33 to move towards the storage means 20 of the sleepers 2a, 2b, represented here by a wagon as described above. The old sleeper 2a is placed in the exchange zone 22 then stored via the handling gantry 23 in one of the dedicated racks 21.

[0097] This step P14 preferably ends when all the old sleepers 2a separated in step P12 are stored in the storage means 20.

[0098] At this stage, the initiation phase A) is completed and the process P implemented by the work train 100 enters a so-called nominal phase B), that is to say that the site is in a repeated, quasi-automatic operating mode.

[0099] At a step P16 or step B1), a new sleeper 2b is inserted by means of the articulated arm 311 through the opening 92 into the free volume 90 and then, after rotation in this free volume 90, is secured to the rails 3 and other elements of the track IA, IB. In other words, the process of step P16 can be considered as being the reverse of the process of step P14. Indeed, a new sleeper 2b is recovered from the storage means 20, for example in the exchange zone 22, by the articulated arm 311. The carriage 310 carrying the articulated arm 311 is maneuvered to bring the new sleeper 2b above the work zone, to pass the new sleeper 2b between the two beams 32 then into the opening 92. It is understood that the new sleeper 2b is oriented substantially along the axis of the rails 3. A rotation of the new sleeper 2b is carried out in the free volume 90 by the articulated arm 311 so as to place the new sleeper 2b substantially perpendicular to the rails 3.The new sleeper 2b is then secured by means of lag screws 5 by the operator(s) of the decoupling / coupling station 320 to the rails 3 and other elements of the track IA, IB in place of an old sleeper 2a removed, preferably the first old sleeper 2a removed. It is understood that once the new sleeper 2b is secured, the opening 92 has a length less than the length of a sleeper 2a, 2b.

[0100] At a step P18 or step B2), the new ballast 4b is spread on the track IA, IB through the ballast hopper 330 to partially fill the free volume 90 under the track IA, IB (figures 14 and 18B). This filled part can for example be the volume separating the newly laid new sleeper 2b and the previous sleeper. The new ballast 4b is, beforehand, conveyed from the storage means 40 of the new ballast 4a to the hopper 330 by the conveyor 60.

[0101] At a step P19, compaction of the new ballast 4b can be carried out by means of the compactor 350 between the new sleepers 2b.

[0102] At a step P20 or step B3), the old ballast 4a is sucked between at least the rails 3 and two new old sleepers 2a still secured to the track. It is understood that these two new old sleepers 2a are located after the plurality of old sleepers 2a already detached at step P14. It is further understood that this step allows to enlarge the free volume 90. These new old crosspieces 2a are therefore located at one end of the free volume 90.

[0103] Prior to this step P20, a step P08' identical to step P08 can be carried out.

[0104] At a step P22 or step B4), the old ballast not sucked up at step P20 is folded back by means of the regulator 341 as at step Fold.

[0105] In a step P24 or step B5), a new old sleeper 2a is separated from the rails 3 and the other elements of the track IA, IB, in a manner similar to that of step P12. It is understood that the new old sleeper 2a which is separated is the one which is located at one end of the opening 92 and that once separated, it falls or is deposited on the bottom of the excavation 91. In this way, the length of the opening 92 remains substantially equal to that formed in step P12. It is understood that the length of the opening 92 at the end of this step P24 must be greater than the length of the opening 92 at the end of step P16.

[0106] In step P26 or step B6), the new old crosspiece 2a is removed through the opening 92 then stored in the storage means (20) of the crosspieces 2a, 2b in a manner similar to that of step P14.

[0107] At a step P28 or step B7), the previously described steps P16 to P26 are repeated in the same order until the ballast and sleepers of the predefined portion of track IA, IB are renewed.

[0108] With reference to the time indicators from 02:02:00 to 02:23:00 of [Fig.l8B], to conclude the work, the process P may comprise, taking place after the nominal phase B), i.e. after the step P28, a finishing phase C) which comprises the following additional steps: Cl) by means of the articulated arm 311, insert through the opening 92 then, after rotation in the free volume 90, place on the bottom of the excavation 91 a plurality of new sleepers 2b, the plurality of new sleepers 2b being equal in number to the plurality of old sleepers 2a from step A3), the new sleepers 2b having been recovered in the storage means 20 of the sleepers 2a, 2b; C2) attach each new sleeper 2b of the plurality of new sleepers 2b to the rails 3 of the track IA, IB so as to close the opening 92 opening into the free volume 90; and C3) ballast the new ballast 4b on track IA, IB so as to fill the free volume 90.

[0109] Thus, at a step P30 or step C1), a plurality of new sleepers 2b are recovered one by one in the storage means 20 of the sleepers 2a, 2b by the articulated arm 311 before being placed on the bottom of the excavation 91 under the rails 3, each new sleeper 2b being previously turned in the free volume 90 so as to be substantially perpendicular to the rails 3. It is preferred that the plurality of new sleepers 2b comprises a number of new sleepers 2b equal to the number of old sleepers 2a of the plurality of old sleepers 2a described in step P12 or step A3).

[0110] It is understood that at this step P30, the new sleepers 2b must necessarily all be placed on the bottom of the excavation 91 before being secured because, otherwise, they could no longer be inserted under the rails 3.

[0111] At a step P32 or step C2), the new sleepers 2b placed on the bottom of the excavation 91 are secured one after the other to the rails 3 and other elements of the track IA, IB so as to close the opening 92 leading into the free volume 90.

[0112] At a step P34 or step C3), the new ballast 4b is spread on the track IA, IB through the ballast hopper 330 to fill the free volume 90 under the track IA, IB. The new ballast 4b can be conveyed in the same manner as in step P18.

[0113] After step P34, a step P19' identical to step P19 can be carried out.

[0114] At step P36, the time allowed for carrying out the work is completed and track IA, IB is returned to commercial metro traffic.

[0115] It will be noted that the means implemented at each stage of the method P are supplied with electrical energy by batteries.

[0116] It should be noted that the method P as described above does not take place entirely statically. Indeed, the work train 100 advances as part of the track portion IA, IB is renewed as shown in the kinematic breakdown of the method P in FIGS. 18A and 18B. The work train 100 only advances when all of the tasks described above are completed, i.e. the tasks of suction, leveling, decoupling, sleeper maneuvering, securing and ballasting and when the compacting task is completed.

[0117] Also, it is important to note that the localized deconsolidation of track IA, IB and the sequencing of the steps of method P allow that at no time do the bogies 31 of the main wagon 30, nor any other bogie of the work train 100, roll on the part of track IA, IB which is in the air, without the support of a ballast.

[0118] Figures 18A and 18B relate more specifically to the kinematic breakdown of the method P implemented by a single work train 100 in a given time to carry out the renewal of a predefined portion of an IB tire track. The time t indicating the time elapsed (in hours, minutes, seconds) since the actual start of the work is given as an expected example of the implementation of the method P. Thus, it is expected that by following the method P, in less than 2h30, the work train 100 can allow the replacement of at least 21 old sleepers 2a with its associated ballast, i.e. approximately 12.5 linear meters of IB tire track, in especially when the travellage, that is to say the spacing between the sleepers, is 60 cm.

[0119] The IB tire tracks have a more complex construction than the classic IA railway tracks, it is expected that the efficiency of the renewal of the ballast and the sleepers on these IA tracks, under conditions identical to those described previously, is approximately twice that on IB tire tracks, which represents approximately 42 old sleepers 2a with their associated ballast, or approximately 25 linear meters.

[0120] It should be noted that the efficiency can be further improved by using several work trains 100. For example, the work trains can be placed one after the other on the same track or else be placed one on a first track and another on the adjoining track.

[0121] In light of what has been described in the foregoing, it is clear that the work train 100 according to the invention allows an improvement in the efficiency of the ballast and sleeper renewal operations on a portion of track. Indeed, the centralization on a single wagon of the various tools necessary for the renewal allows an optimization of the operations in their sequence and in their duration. On the one hand, the sleeper detachment / attachment station facilitates the work of the operators to remove the fasteners of the old sleepers and fix the new ones by having them intervene directly above the rails, and, on the other hand, the trolley with its articulated arm ensures the handling of the sleepers directly from above the track, the articulated arm passing between the beams of the main wagon to have access to the track.In addition, the articulated arm allows the old sleepers to be stored directly in the storage facility, in particular, when provided, in a volume dedicated to the exchange of sleepers and then to recover new ones to be installed.

[0122] Another advantage is to ensure that the track elevation is maintained. In fact, when implementing the method, the rails are not dismantled and remain in place. A portion of the rail is thus kept in the air, without resting on the ballast, which facilitates work on the track and the removal / installation of sleepers.

[0123] Another advantage, linked to the centralization of the various tools on the main wagon, is the “compact” aspect of the work train which allows it to operate efficiently in confined environments.

[0124] Yet another advantage is to allow an improvement in operator safety. Indeed, operators no longer operate directly in the bottom of the excavation to separate / reconnect the sleepers and remove / install them. In addition, since the articulated arm is located directly on the beams of the main wagon and passes between these beams, the risks of a collision with an operator are greatly reduced since the articulated arm has no reason to pivot outside the axis of the track.

Claims

1. Claims Work train (100) for the renewal of ballast and sleepers of a portion of track (IA, IB), said portion of track comprising at least one pair of rails (3), sleepers (2a), called old, and the ballast (4a), called old, said work train comprising: - a suction device (10) for the old ballast (4a) from the track as well as a storage means (50) for the associated old ballast, - a means of storing (20) the sleepers (2a, 2b), - a main wagon (30) provided with two bogies (31) between which extend two beams (32) parallel to each other, said beams (32) having an overall omega shape and each comprising at each end a lower part (34, 34') linked to a bogie (31) and an upper part (35),, said main wagon (30) comprising, from front to rear in the direction of travel: • a leveling station (340) comprising at least one leveler (341) mounted under the two beams (32), said leveler (341) being configured to fold, by means of at least one arm (342) movable in rotation, the old ballast (4a) not sucked up by the suction device (10), located under each end of a sleeper (2a), towards the center of the track (IA, IB), so as to form under the track a excavation bottom (91), • a carriage (310) mounted movable in translation on and along the beams, the carriage comprising an articulated arm (311) provided with a gripping element (314) rotating so that the articulated arm has access to the track (IA, IB) by passing between the two beams to, on the one hand, remove the old sleepers (2a) from the track (IA, IB) and, on the other hand, lay new sleepers (2b), • a station for disconnecting / connecting (320) the sleepers (2a, 2b) to the rails (3) suspended from the two beams (32) and configured to translate along the two beams, said station for disconnecting / connecting the sleepers being arranged so that the articulated arm (311) has access to the track, • a track ballast hopper (330), - a means (40) for storing new ballast (4b) as well as a ballast conveyor (60) extending from the means for storing new ballast to the ballast hopper (330).

2. A work train (100) according to claim 1, wherein the two beams (32) have a spacing between them taken at the upper part (35) which is less than a spacing between the beams (32) taken at a lower part (34, 34').

3. A work train (100) according to any one of claims 1 or 2, wherein the main wagon (30) comprises a control cabin (312) for the trolley (310) and the articulated arm (311), suspended between the two beams (32), so that in use an operator has a clear view of the track from the control cabin (312).

4. Work train (100) according to any one of claims 1 to 3, wherein the main wagon (30) comprises an articulated support (360) for a suction head (12) of the suction device (10) of the old ballast (4a).

5. Work train (100) according to any one of claims 1 to 4, in which the station (320) for detaching / attaching the sleepers (2a, 2b) to the rails (3) comprises two seats (322), each being suspended from one of the two beams above a rail (3) and configured to translate perpendicular to the two beams (32).

6. Work train (100) according to any one of claims 1 to 5, wherein the regulator (341) is configured to be movable in axial and lateral translation relative to the beams (32).

7. Work train (100) according to any one of claims 1 to 6, wherein said at least one arm (342) of the regulator (341) has a width at most equal to a spacing between two consecutive sleepers (2a).

8. A work train (100) according to any one of claims 1 to 7, wherein the regulator (341) is arranged to be, in use, supported on the rails (3) of the track.

9. Work train (100) according to any one of claims 1 to 8, wherein the main wagon (30) comprises a compactor (350) provided with at least one vibrating plate (351) for crushing and distributing the new ballast (4b) between at least two new sleepers (2b), said compactor (350) being suspended from the two beams (32), said compactor being movable in axial and lateral translation relative to the beams.

10. Work train (100) according to any one of claims 1 to 9 comprising batteries for an autonomous electrical supply of the work train.

11. Method (P) for renewing ballast and sleepers of a portion of track (IA, IB) implemented by a work train (100) according to any one of claims 1 to 10, said method comprising: - A) a priming phase comprising the following steps: Al) sucking (P10) between at least the rails (3) of the track (IA, IB) the old ballast (4a) by means of the suction device (10) so as to form a free volume (90) under the rails (3), said free volume (90) having a length, defined according to the orientation of the rails (3), at least equal to a length of an old (2a) or new (2b) sleeper; A2) fold (Fold) into the free volume (90), using the leveler (341), the old ballast (4a) not sucked up towards the center of the track (IA, IB) and level the old ballast (4a) not sucked up under the track to form a substantially flat and uniform excavation bottom (91);A3) detaching (P12) a plurality of old sleepers (2a) from the rails of the track so as to form an opening (92) defined in the plane of the rails (3) and opening into the free volume (90) and having a length at least equal to the length of an old (2a) or new (2b) sleeper, said old sleepers (2a) falling onto the excavation bottom (91) once detached; A4) for each detached old sleeper, grasping and turning in the free volume the detached old sleeper by means of the articulated arm (311), then removing (P14) said detached old sleeper through the opening (92) before storing said detached old sleeper in the sleeper storage means (20);- B) a nominal phase comprising the following steps: B1) by means of the articulated arm, insert (P16) through the opening (92) then, after rotation in the free volume, secure to the rails of the track a new sleeper (2b) in place of an old sleeper (2a) removed, said new sleeper having been recovered from the sleeper storage means (20); B2) ballast (P 18) the new ballast (4b) through the ballast hopper (330) so as to partially fill the free volume (90), said new ballast having been conveyed from the new ballast storage means (40) to said hopper by a conveyor (60); B3) sucking up (P20) the old ballast between at least the rails (3) and two new old sleepers still secured to the rails; B4) folding down (P22) the unsucked old ballast as in step A2); B5) separating (P24) a new old sleeper (2a) from the track rails so that the length of the opening (92) remains substantially equal to that formed in step A3), said new old sleeper (2a) falling onto the excavation bottom (91) once separated; B6) grasping and turning in the free volume the new old sleeper separated by means of the articulated arm, then removing (P26) the new old sleeper separated through the opening before storing the new old sleeper separated in the sleeper storage means; and B7) repeat (P28) steps Bl) to B6) until the ballast and sleepers of the predefined portion of the track (IA, IB) are renewed.

12. Method (P) according to claim 11 comprising, after the nominal phase B), a finishing phase C) which comprises the following steps: C1) by means of the articulated arm, inserting (P30) through the opening (92) then, after rotation in the free volume, depositing on the bottom of the excavation (91) a plurality of new sleepers (2b), the plurality of new sleepers (2b) being equal in number to the plurality of old sleepers (2a) of step A3), said new sleepers having been recovered from the sleeper storage means (20); C2) securing (P32) each new sleeper (2b) of the plurality of new sleepers to the rails of the track so as to close the opening (92) opening into the free volume (90); and C3) ballasting (P34) the new ballast (4b) on the track so as to fill the free volume (90).

13. Method (P) according to any one of claims 11 or 12, in which, in steps A1) and B3), the old ballast (4a) is sucked under the old sleepers (2a) to a depth of between 20 cm and 50 cm.

14. Method (P) according to any one of claims 11 to 13, in which, prior to steps A1) and B3), the old ballast (4a) is moistened by means of a watering device (370).

15. Method (P) according to any one of claims 11 to 14, in which the excavation bottom (91) is located under the sleepers (2a, 2b) at a depth of between 20 cm and 30 cm.

16. Method (P) according to any one of claims 11 to 15, in which each of the rotations of steps A4) and B6) is carried out so that the old sleeper is positioned substantially in the axis of the rails (3).

17. Method (P) according to any one of claims 11 to 16, in which, after ballasting, a step of compacting the new ballast (4b) is carried out by a compactor (350) between the new sleepers (2b) joined together.

18. Method (P) according to any one of claims 11 to 17, wherein each step of the method (P) is powered with electrical energy by batteries.

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