1 Title: Track warning system for monitoring at least a portion of a railway track for railway workers, as well as a safety helmet for such system. 5 Description The present invention relates to a track warning system for monitoring at least a portion of a railway track for railway workers, as well as a safety helmet for such a track warning system. In order to ensure the safety of the maintenance workers on the 10 track, also known as railway workers or track workers or rail gang in short, often a certain part of the railway track, for example, one or more sections thereof, are taken out of service. During the time that a portion of the railway track is taken out of service, that part of the railway track can not be used at that time and this may 15 cause undesirable disruption to the (public) timetable. Especially when it is a heavily used part of the railway network, or when work must be carried out at the wrong time of day, during rush hour for example. At these times it may be undesirable that the specific part of the railway track is taken out of service. In such a case, maintenance should be carried out on an in-service section of the railway track, in between 20 moments in which trains pass. In order to warn the rail gang of an approaching train, is known to use track warning systems that warn the rail gang so that they can move in a timely manner to a safe area. Such known detection systems communicate via a radio frequency, RF signal to the warning means, further ahead in proximity to the rail track workers and therefore the servicing. 25 Such communication has the disadvantage of being susceptible to malfunction. Also, the range or coverage is short and moreover, a current status can not be determined. An embodiment of the invention seeks to provide an improved track warning system. More particularly, a track warning system that provides a solution to 30 at least some of the above-mentioned drawbacks. Alternatively or additionally, an embodiment of the invention seeks to at least provide the public with a useful choice. In accordance with a first aspect of the invention, there is provided a track warning system for monitoring at least a portion of a railway track for railway 35 track workers, comprising: at least one train detection unit, comprising detection means arranged for detecting the presence of a train in the section of the railway track, as well as communication means arranged for communicating information 2 concerning the presence of the train; at least one signaling unit, comprising communication means arranged to communicate with the communication means of the at least one train detection unit, as well as signaling means arranged for outputting of at least a warning signal to the railway track workers indicative of the 5 presence of the train, wherein the communication means of the at least one train detection unit and the at least one signaling unit are further arranged to communicate over a public wireless telecommunication network, being one or more of GSM-R, HSDPA, HSUPA, 3GPP LTE, LTE ADVANCED and further generations. In accordance with a second aspect of the invention, there is 10 provided a safety helmet for use by railway track workers, arranged for a track warning system according to the first aspect described above, comprising communication means for communicating with at least one or more of the train detection unit, the signaling unit, a local area network router and a remotely located server , as well as signaling means arranged for emitting at least one or more of a 15 vibration signal, an audible signal and a visual signal, wherein the communication means are arranged to communicate over a public wireless telecommunication network, being one or more of GSM-R, HSDPA, HSUPA, 3GPP LTE , LTE ADVANCED and further generations. 20 The railway network is being used more and more intensively and must meet increasing conditions. Therefore regular maintenance is required. In order to safely carry out the maintenance work, portions of a track can be taken out of service, for example, with a presently known shunt bars. It may be considered desirable to take heavily trafficked parts of the 25 track out of service or to perform maintenance during busy times of the day, such as during rush hour. In such a case, it should be possible to carry out the maintenance on an in-service section of the track, in between the moments the trains passes. The present disclosure therefore provides a track warning systems to safeguard the rail gang by warning them of an approaching train so they can move in a timely manner 30 to a safe area. Such a tack warning system consists in its most simple embodiment of at least one train detection unit and at least one signaling unit. The train detection unit comprises detection means for detecting the presence of a train, either by detection in or near the track, or directly from the train security system (interlocking). 35 Further, the train detection unit comprises communication means which are arranged to communicate information concerning the presence of the train to other units of the system. When a train comes within range of the detection means, or the 3 security system detects the train, a signal will be send which is communicated by said communication means to other components of the track warning system, such as, for example, to the signaling unit. The signaling unit includes corresponding communication means to 5 receive the signal, and signaling devices which deliver one or more warning signals to the rail gang, in order to warn them of the approaching train. This may be an audible signal, but also a visual signal or a combination of both. The inventor has come to realize that all existing track warning systems are used for local activities. To this end they will also be installed locally 10 and hence accordingly communicate locally. This conventional point-to-point type of communication creates several problems. For example, the range of such a local networks is limited, which may be a limiting factor in the distance required between the train detection unit and the signaling unit. Further, such local (radio) communication is not always reliable and the information that is communicated is 15 only available locally. To this end, a track warning system according to the present disclosure is characterized by communication means of both the train detection and the signaling unit that are able to communicate over a wireless public telecommunications network, being one or more of GSM-R, HSDPA, HSUPA, 3GPP 20 LTE, LTE Advanced, or further generations. This has several advantages, the range is so large that availability is not an issue anymore. Because of the network, range not being a limiting factor anymore. Repeaters are therefore superfluous. Also, continuous testing of the connection is unnecessary. Furthermore, bandwidth is not a limiting factor anymore, 25 and can even be used according to the needs of the system or can be scaled-up. Another major advantage is that the communication by such a matter is taken out of the local zone and, in principle, can be made widely available and can be adapted or applied accordingly. A track warning system that communicates through such a network, results in improved availability, higher 30 reliability, higher speed and greater bandwidth. Such a track warning system further provides the ability to give multiple users at all levels within the railway system insight in the situation on site, such that, if necessary, can be intervened. The invention will be explained in more detail, by way of non-limiting example only, with reference to the figures, in which figures: 35 Figure 1 shows a section of a railway track with a overview of the various components of a track warning system according to an embodiment of the invention; 4 Figure 2 shows a sketch of the situation of a track warning system in a section of a railway track with a few components of a track warning system according to an embodiment of the invention; Figures 3 shows a safety helmet of a track warning system 5 according to an exemplary embodiment of the invention. For better understanding of the invention, the corresponding parts in the following description of the figures will be referred to with identical reference numerals. In Fig. 1 is illustrative of a portion shown of a railway track 105 10 which consists of several rails 105a-d. Trains can ride along these rails. In this figure, two sets of rails 105a-b and 105c-d are shown. In the middle of the rails, this part is displayed by the interruption in the rails 105a-d, a work area or work zone is defined 190. Within this work area, the (maintenance) work is carried out. During the work, the railway workers or railway gang should be timely warned of an 15 approaching train, such that they can leave the work zone 190 in time and the risk of accidents is minimized. It is important that the railway gang can therefore count on a reliable, accurate warning system that warns them timely so that there is still sufficient time to leave the work area 190. The track warning system 100 is therefore provided in its most 20 minimal embodiment of at least one train detection unit 110, 111 and at least one signaling unit 120, 121, 150. In practice, however, it will usually more likely be a plurality of detection units and a plurality of alarm units, such as the current situation may require and, for example, depending on the size of the work area 190, the number of railway works, and the time duration, or the ambient noise on the site. 25 In the track warning system 100 of FIG. 1 six train detection units 110a-d, 111a-b are present and shown. These can be of various types. Some are disposed in between the tracks 105a-d. Others are arranged close to the track and of the ultrasonic type 111a-b, which detect the presence of a train on the basis of an ultrasonic signal. These are aimed in a direction from which to expect a train. 30 As shown in Fig. 1, all components of the system 100 are connected with each other. This is illustrative shown in the form of the lines 175 between the various units. These lines are to be considered only illustrative and not intended to be a representation for a physical wired connection between the specific parts of the system. This connection could be carried out in a wired manner, but in a 35 practical embodiment it is often wirelessly. Further, it may also be a combination of both. That is to say, that some units are wirelessly connected and other wired or partially wired and partially wireless. The track warning system according to the 5 invention does not communicate via a local point-to-point radio link but via a public wireless telecommunications network. That is to say, with public is meant that the units of the system 100 are also accessible outside the working zone 190, and communication between the various components/units of the system 100 takes 5 place over a public network. Various forms of non-local communication are also conceivable. All of the examples of the train warning system according to the invention communicate over a public wireless telecommunication network according to claim 1. With a telecommunications network is in the context of the invention meant, a composition 10 of different nodes, by which one or more connections can be made possible between two or more terminals of the network. Over these connection electron communication can take place. This electronic communication could relate to data as well as telephony, or a combination thereof, packet and/or circuit switched. In Fig. 1, the system 100 comprises a central unit 160. This is a 15 (central or non-central/local) server 160. This server is considered central, because it is in a position to be able to see at least all communication between the various components of the system 100 and/or to read-out but also be able to store, but also to adapt in a further embodiment. If one of the train detection units detects a train (which train can also be detected from the train safety system, e.g. the interlocking) 20 this information about the presence, or approach of the train will be communicated to the signaling unit. This communication occurs always via the telecommunications network to which the server 160 is connected and via which network all the components, including the server 160, are in communication with each other. This allows the server 160 to read-out the information, to save it for later perusal, but it 25 can also be manipulate and/or configured. As indicated, it is important that, for example in the situation of an accident, that possibilities exist which make it possible to, afterwards, determine whether a train was detected, when it had occurred, and/or a warning signal is issued and if yes, when, etc. The saving, or logging, of all kinds of data can be 30 carried out locally. That is to say, for every part of the system, in the part itself. It can, however, also be performed centrally, preferably by the server 160. In an alternative, it may also at be performed at both ends. If the logging is carried out in the server, it can be made available elsewhere (widely) by the server. For example, to a central train management or planning department 170. 35 Another important advantage is that the configuration can be done remotely. That is to say, this can create temporary or (semi) permanent configurations for the track warning system. This in turn has the advantage that the 6 configuration can be performed prior to the work and does not need to be carried out on-site. This saves valuable time and the period which is necessary in order to carry out the relatively dangerous work on a track that has not been taken out of service, may be limited to only the time for the actual work without the additional time for 5 setting up and configuring of the track warning system. Another additional advantage is that the track worker, in comparison with conventional warning systems, need to be present in an unattended track in less time. After all, conventional track warnings system must be installed first and then configured and tested. Only after all these steps have been carried out, the 10 system can be put into use. Since this part of the track is not taken out of service, this is a dangerous period in which the track workers present in or near a track which is in use and not taken out of service, and for which the track warning system is not yet operational. In order to ensure safety, the this time period should be minimized, but preferably reduced, most preferably reduced to zero. This can be 15 realized with a track warning system according to the invention, because at least the configuration and testing can be carried out remotely, such that the various components of the system 100 can be controlled remotely via the telecommunication network. If use is made of train detection units and/or signaling units that are permanently installed, the railway worker does not need to go in or near the track, 20 but only configuration and testing is needed to be performed at a sufficient distance from the dangerous track, by which a safe workplace can be realize. In Fig. 1 is shown for this purpose, for example, a control unit 140. This is, for example, a tablet with an application that via the telecommunications network is in communication with the various components of the system 100 and 25 with the central server 160. By means of this tablet 140, for example, a railroad worker can activate the train detection units, and link them to a signaling unit in order configure a guarded work zone 190. With the tablet 140 subsequently also a test can be carried out, in order to determine whether the configuration can be put safely in operation. The tablet can also be used as a source of information by which, 30 in a passive manner, status information can be read-out from the various components of the system. For those entitled, the application can, either through the tablet 160 or via another device such as a (smart) phone, laptop or desktop computer set the configuration via the telecommunications network. In an example, a specially equipped department within the railway management could for this 35 purpose schedule maintenance work for a portion of the track. The work area 190 in which these activities are performed, can then be monitored by a track warning system according to the invention, of which the configuration of the system is pre- 7 configured by this department in accordance with the defined work area 190. For example, one can select a configuration consisting of one mobile detection unit 120 which is arranged to alert the railway gangs by means of a sound signal and light, one mobile detection unit 121 which alarms with a strong sound, and per direction 5 and per rail one inductive detection unit 110a-d, and per direction one ultrasonic detection unit 111a-b. Optionally, a shunt bar, ZKL 130, can be added to the track warning system, and/or one or more safety helmets 150. As soon as the department has coupled/linked the various components within the system 100 the first step of the configuration is ready. An additional, but preferred second step may be carried 10 out to test all components of the configuration during a test phase. If the test phase has been successfully completed, the maintenance job can be made available to a contractor who will carry out the maintenance work on the track at the work area 190. This job will, for example, be made available via a tablet 140, by which a command presented on the screen is activated by the department. In this order, the 15 track warning system 100 is configured appropriately for the work area 190. The contractor on site, only needs to accept and the order by an activation command and the maintenance work can be started. In Fig. 1 is further also shows a shunt bar 130. This shunt bar is able to create a short circuit between the rails 105c-d so that the relay of the track 20 circuit current system drops out and the signal of the section to which the zone belongs work jumps red. This can be included as an additional safety measure in the system 100. Fig. 2 also shows a work station or work area 190, in which railway gangs can carry out 220 (maintenance) work. With reference 210a a train is 25 indicated approaching the area 190 on the track. This train is detected by the detection units 110b. This detection unit is in communicative connection with the central server 160 via a telecommunication network in accordance with the description of Fig. 1. The server can optionally be present locally, but is located in a preferred embodiment, at some distance from the work area 190, for example, in a 30 central data center. Fig. 3 shows a safety helmet 300 according to an aspect of the invention. This safety helmet is arranged for alarming the user of the helmet is several manners. For example, by means of a (LED) light 320 which is aimed directly at the eyes of the user, and lights up if a signal is received from a train 35 detection unit that detects an approaching. Furthermore, the helmet includes a vibration module 340 which vibrates upon receiving such a signal and thus alerts the user accordingly. In addition, the helmet 150 includes one or more speakers 330, 8 which can alarm the user by means of a sound signal. The whole communicates with the other components of the system via a communications module that is not shown but is arranged for the system according to claim 1. With the aid of the LEDs 310, the status can be read-out and be seen whether there is, for example, an incoming 5 message, or whether the connection to the network is still live/operable. To this end, the logo can also light up to indicate that the helmet is activated. The term 'comprising' as used in this specification and claims means 'consisting at least in part of'. When interpreting statements in this specification and claims which include the term 'comprising', other features besides 10 the features prefaced by this term in each statement can also be present. Related terms such as 'comprise' and 'comprised' are to be interpreted in similar manner. In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the 15 invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art. 20